KINDAI UNIVERSITY


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NISHIKAWA Hiroaki

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FacultyDepartment of Biomedical Engineering / Graduate School of Biology-Oriented Science and Technology
PositionProfessor
Degree
Commentator Guidehttps://www.kindai.ac.jp/meikan/355-nishikawa-hiroaki.html
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Last Updated :2020/09/01

Education and Career

Education

  •   1989 04  - 1993 03 , Kindai University, Faculty of Science and Engineering

Academic & Professional Experience

  •   2018 04 ,  - 現在, Faculty of Biology-Oriented Science and Technology, Department of Biomedical Engineering, Kindai University
  •   2010 04 ,  - 2018 03 , Faculty of Biology-Oriented Science and Technology, Department of Biomedical Engineering, Kindai University
  •   2011 12 ,  - 2012 03 , The Institute of Scientific and Industrial Research, Osaka University
  •   2008 04 ,  - 2010 03 , Faculty of Biology-Oriented Science and Technology, Department of Electronic Systems and Information Engineering, Kindai University
  •   2003 04 ,  - 2008 03 , Faculty of Biology-Oriented Science and Technology, Department of Electronic Systems and Information Engineering, Kindai University
  •   1998 04 ,  - 2003 03 , Faculty of Biology-Oriented Science and Technology, Department of Electronic Systems and Information Engineering, Kindai University

Research Activities

Research Areas

  • Manufacturing technology (mechanical, electrical/electronic, chemical engineering), Electronic devices and equipment
  • Nanotechnology/Materials, Thin-film surfaces and interfaces
  • Nanotechnology/Materials, Crystal engineering
  • Nanotechnology/Materials, Applied materials
  • Nanotechnology/Materials, Composite materials and interfaces

Published Papers

  • Fabrication of Flexible BaTiO3 Thin Films, S. Umatani, H. Nishikawa, IEEJ Transactions on Electronics, Information and Systems, IEEJ Transactions on Electronics, Information and Systems, 139(3), 211 - 212, Mar. 2019 , Refereed
  • Controlling the Chemical Composition of Hydroxyapatite Thin Films using Pulsed Laser Deposition, H. Nishikawa, R. Yoshikawa, Trans. Mat. Res. Soc. Japan, Trans. Mat. Res. Soc. Japan, 40, 111 - 114, Jun. 2015 , Refereed
  • バイオセラミックスの現状と新展開 アパタイト薄膜の形成とバイオセンサへの応用, HONTSU SHIGEKI, NISHIKAWA HIROAKI, KUSUNOKI MASANOBU, J Soc Inorg Mater Jpn, J Soc Inorg Mater Jpn, 19(361), 504 - 510, Nov. 01 2012
  • Examination of enamel regeneration method using the hydroxyapatite/α-TCP composite sheet, Hontsu Shigeki, Yoshikawa Kazushi, Matsuda Taiyo, Kusunoki Masanobu, Maruyama Toshiro, Yamamoto Ei, Kato Nobuhiro, Nishikawa Hiroaki, Preprints of Annual Meeting of The Ceramic Society of Japan
    Preprints of Fall Meeting of The Ceramic Society of Japan, Preprints of Annual Meeting of The Ceramic Society of Japan
    Preprints of Fall Meeting of The Ceramic Society of Japan, 2012(0), 706 - 706, 2012 , Refereed
    Summary:We have succeeded to regenerate tooth enamel by using flexible hydroxyapatite (HAp) sheets. In this study, we tried enamel regeneration by composite sheet which deposited a α-TCP thin film on the HAp sheet. The HAp/α-TCP composite sheets are stick onto polished surface of extracted teeth with calcium phosphate solution. The time dependence of the composition at the interfaces between the composite sheet and the teeth surfaces was evaluated by an X-ray diffraction (XRD) method. After one day past, the XRD pattern completely matched with that of teeth enamel. Also, the adherence between composite sheet and teeth enamel was evaluated by tensile test.
  • Regeneration of enamel by a self-organization process of apatite sheet, Hontsu Shigeki, Yamamoto Kazuyo, Kato Nobuhiro, Yamamoto Ei, Maruyama Toshiro, Matsuda Taiyo, Nisikawa Hiroaki, Kusunoki Masanobu, Hayami Takashi, Yoshikawa Kazushi, Preprints of Annual Meeting of The Ceramic Society of Japan
    Preprints of Fall Meeting of The Ceramic Society of Japan, Preprints of Annual Meeting of The Ceramic Society of Japan
    Preprints of Fall Meeting of The Ceramic Society of Japan, 2011(0), 231 - 231, 2011 , Refereed
    Summary:We have attempted to regenerate tooth enamel artificially by using flexible hydroxyapatite (HAp) sheets. The sheets are affixed onto polished surface of extracted teeth with calcium phosphate solution. The time-dependent variation of the composition at the interfaces between the HAp sheets and the teeth surfaces was evaluated by an X-ray diffraction (XRD) method. After one week past, the XRD pattern completely matched with that of teeth enamel. The adherence between HAp sheet and teeth enamel was evaluated by tensile test using a stainless rod with a diameter of 3 mm glued onto the HAp sheet. The test validated that the adherence between HAp sheet and tooth enamel is much stronger than 3.4 MPa in affixing post-21 days.
  • Superconducting magnetostatic wave devices using HTS/perovskite - type manganite PCMO heterostructure, M. Terakago, S. Mine, T. Sakatani, S. Hontsu, H. Nishikawa, M. Nakamori, H. Tabata, T. Kawai, Supercond. Sci. Technol., Supercond. Sci. Technol., 14(12), 1140 - 1143, Dec. 2001 , Refereed
  • Mechanically Tunable High - Temperature Superconducting Microwave Filter with Large Shift of Resonant Frequency, S. Hontsu, T. Sakatani, A. Fujimaki, H. Nishikawa, M. Nakamori, T. Kawai, Jpn. J. Appl. Phys., Jpn. J. Appl. Phys., 40(11A), L1148 - L1150, Nov. 2001 , Refereed
  • Preparation of Superconducting Magnetostatic Wave (MSW) Devices Consisting of High - Tc superconductor (HTS)/ Perovskite - Type Manganite Heterostructures: Application of Pr0.85Ca0.15MnO3 as a MSW Waveguide, S. Hontsu, T. Sakatani, H. Nishikawa, M. Nakamori, A. Fujimaki, T. Kawai, Jpn. J. Appl. Phys., Jpn. J. Appl. Phys., 40(10B), L1100 - L1102, Oct. 2001 , Refereed
  • Mechanism for excimer-laser ablation in alkaline-earth metals, H. Nishikawa, M. Kanai, G. Szabo, T. Kawai, Phys. Rev. B, Phys. Rev. B, 61(2), 967 - 973, Jan. 2000 , Refereed
  • Time-Resolved Studies of Ion Desorption from Ca surfaces Using Double-Pulsed Laser Ablation Technique, H. Nishikawa, G. Szabo, T. Kawai, Jpn. J. Appl. Phys., Jpn. J. Appl. Phys., 35(8A), L985 - L988, Jul. 1996 , Refereed
  • Effect of laser fluence and ambient gas pressure on surface morphology and chemical composition of hydroxyapatite thin films deposited using pulsed laser deposition, Hiroaki Nishikawa, Tsukasa Hasegawa, Akiko Miyake, Yuichiro Tashiro, Satoshi Komasa, Yoshiya Hashimoto, APPLIED SURFACE SCIENCE, APPLIED SURFACE SCIENCE, 427(Part B), 458 - 463, Jan. 2018 , Refereed
    Summary:The dependence of the surface morphology and chemical composition of hydroxyapatite (HA) thin films on the laser fluence and ambient gas pressure during their formation by pulsed laser deposition was studied as the first step to investigate the effect of physical and chemical interactions between the ablated chemical species and ambient gas molecules on HA film formation. It was found that a higher fluence could decrease the number of large protrusions on the surface of HA thin films. However, too high a fluence caused a phosphorus deficiency from the stoichiometric value, particularly in the case of lower ambient gas pressure. It was also found that for lower fluences, the atomic species among the ablated chemical species were easily scattered by collision processes with ambient gas molecules. This was caused by the lower velocity of the ablated chemical species and higher ambient gas pressure, which induced a shorter mean free path. In addition, these collision processes played an important role in the adsorption, migration, and re-evaporation of the ablated chemical species on the substrate via chemical reactions. (C) 2017 Elsevier B.V. All rights reserved.
  • Effect of ablation laser pulse repetition rate on the surface protrusion density of hydroxyapatite thin films deposited using pulsed laser deposition, Hiroaki Nishikawa, Shinji Umatani, MATERIALS LETTERS, MATERIALS LETTERS, 209, 330 - 333, Dec. 2017 , Refereed
    Summary:The effect of the pulse repetition rate of the ablation laser on surface protrusion density was investigated for hydroxyapatite thin films deposited using pulsed laser deposition. Atomic force microscope surface images showed a marked decrease in surface protrusion density at lower pulse repetition rate, while protrusion-free areas exhibited similar morphologies independent of the pulse repetition rate. These results indicate that the surface protrusions were not formed or enlarged from surface migration of atomic species on the surface, which formed the smooth surface of the protrusion-free area. The postulated origin of the protrusions was large particles or droplets produced directly from the target irradiated with the ablation laser. These results suggest that the optimum pulse repetition rate for protrusion-free hydroxyapatite thin film surfaces is <= 3 Hz. (C) 2017 Elsevier B.V. All rights reserved.
  • Relationship between the Ca/P ratio of hydroxyapatite thin films and the spatial energy distribution of the ablation laser in pulsed laser deposition, Hiroaki Nishikawa, Tsukasa Hasegawa, Akiko Miyake, Yuichiro Tashiro, Yoshiya Hashimoto, Daveh H. A. Blank, Guus Rijnders, MATERIALS LETTERS, MATERIALS LETTERS, 165, 95 - 98, Feb. 2016 , Refereed
    Summary:Variation of the Ca/P ratio in hydroxyapatite (Ca-10(PO4)(6)(OH)(2)) thin films was studied in relation to the spot size of the ablation laser for two different spatial energy distributions in pulsed laser deposition. One energy distribution is the defocus method with a raw distribution and the other is the projection method without the weak portion at the edges of the ablation laser spot. A Ca/P ratio closer to that of stoichiometry was obtained with the larger spot sizes for both methods, and with the projection method compared to the defocus method. It is considered that a more uniform spatial energy distribution of the ablation laser improves the Ca/P ratio. (C) 2015 Elsevier B.V. All rights reserved.
  • A novel membrane-type apatite scaffold engineered by pulsed laser ablation, Yoshiya Hashimoto, Hiroaki Nishikawa, Masanobu Kusunoki, PeiQi Li, Shigeki Hontsu, DENTAL MATERIALS JOURNAL, DENTAL MATERIALS JOURNAL, 34(3), 345 - 350, Jun. 2015 , Refereed
    Summary:Cell sheet technology is a scaffold-free method for tissue reconstruction. A sheet-shaped scaffold would be suitable for the regeneration of periodontal membrane. We designed a stem cell sheet combining human mesenchymal stromal cells (hMSCs) and a 10-mu m thick biological apatite (BAp) membrane fabricated with an ArF pulsed laser ablation for periodontal regeneration. X-ray diffraction showed that crystalline hydroxyapatite (HAp) was present in BAp and HAp membranes after post-annealing. Energy dispersive analysis of the BAp membrane revealed peaks of Na and Mg in addition to Ca and P. Approximately 3x10(4) hMSCs were cultured on BAp and HAP membranes for 7 and 14 days. From in vitro assays, hMSCs grew faster and had higher osteoblast differentiation when cultured on the BAp membrane than did the cell culture on the HAp membrane. Stem cell sheets combined with a BAp membrane may have potential applications in guided bone regeneration and osteoconductive scaffolds.
  • Evaluation of dentin tubule sealing rate improved by attaching ultrathin amorphous calcium phosphate sheet, Nobuhiro Kato, Arata Isai, Ei Yamamoto, Hiroaki Nishikawa, Masanobu Kusunoki, Kazushi Yoshikawa, Kenzo Yasuo, Kazuyo Yamamoto, Shigeki Hontsu, Key Engineering Materials, Key Engineering Materials, 631, 258 - 261, 2015 , Refereed
    Summary:Dentin hypersensitivity is induced by mechanical stimuli or heat stimuli applied via dentin tubules exposed by lost of dental enamel or gingival recession. Common treatments for dentin hypersensitivity are resin coating or laser irradiation. However, these treatments have some problems such as poor biocompatibility or insufficient durability. We have been developing a treatment that creates artificial tooth enamel by attaching flexible ultrathin calcium phosphate sheet having a crystal structure similar to that of tooth enamel to seal the dentin tubules. In this study, the quantitative evaluation of dentin tubule sealing rate improved by attaching ultrathin amorphous calcium phosphate (ACP) sheet on human dentin is presented. The obtained sealing-rate by APC sheet application was 70.9 ±4.8%.
  • Electronic Reconstruction at the Isopolar LaTiO3/LaFeO3 Interface: An X-Ray Photoemission and Density-Functional Theory Study, J. E. Kleibeuker, Z. Zhong, H. Nishikawa, J. Gabel, A. Mueller, F. Pfaff, M. Sing, K. Held, R. Claessen, G. Koster, G. Rijnders, PHYSICAL REVIEW LETTERS, PHYSICAL REVIEW LETTERS, 113(23), 237402-1 - 237402-5, Dec. 2014 , Refereed
    Summary:We report the formation of a nonmagnetic band insulator at the isopolar interface between the antiferromagnetic Mott-Hubbard insulator LaTiO3 and the antiferromagnetic charge transfer insulator LaFeO3. By density-functional theory calculations, we find that the formation of this interface state is driven by the combination of O band alignment and crystal field splitting energy of the t(2g) and e(g) bands. As a result of these two driving forces, the Fe 3d bands rearrange and electrons are transferred from Ti to Fe. This picture is supported by x-ray photoelectron spectroscopy, which confirms the rearrangement of the Fe 3d bands and reveals an unprecedented charge transfer up to 1.2 +/- 0.2 e(-)/interface unit cell in our LaTiO3/LaFeO3 heterostructures.
  • Water adsorption and desorption on plasma-activated PET film surface, indication of hydrogen bonding, Kazuya Hanada, Miyoshi Yokura, Masatsugu Nagashima, Yuichi Nakamura, Hiroaki Nishikawa, Yuri Strzhemechny, Zorica Orel, Sanapa Lakshmi Reddy, Yukiko Izumi, Shigehisa Tomita, Tamio Endo, JAPANESE JOURNAL OF APPLIED PHYSICS, JAPANESE JOURNAL OF APPLIED PHYSICS, 53(5), 05FB23-1 - 05FB23-6, May 2014 , Refereed
    Summary:A plasma-irradiated poly(ethylene terephthalate) (PET) film has a long lifetime of bonding capability. To clarify its origin, a PET film was irradiated with oxygen plasma. It was then exposed to normal atmosphere including water vapor. FTIR absorption on the irradiated and non-irradiated films was measured at different times after the start of evacuation. The irradiated film has a larger amount of OH than the non irradiated film, and OH is generated on the film surface. The irradiated film has a larger amount of adsorbed water, because the surface is activated by the created OH. The adsorbed water is desorbed rapidly with increasing evacuation time in the non irradiated film, but it is desorbed more gradually in the irradiated film. Water has hydrogen bonds with OH; thus, the water desorption is suppressed. The OH absorption band is shifted to the lower wave number side owing to the hydrogen bonds. The irradiated surface may be protected by the water from the atmosphere. (C) 2014 The Japan Society of Applied Physics
  • Bonding effect of plasma-irradiated PET films can be preserved after soaking in various liquid reagents, Miyoshi Yokura, Kenichi Uehara, Kazuya Hanada, Yoshinobu Nakamura, Hiroaki Nishikawa, Tetsuo Tsuchiya, Sanapa Lakshmi Reddy, Reji Philip, Yukiko Izumi, Shigehisa Tomita, Tamio Endo, JAPANESE JOURNAL OF APPLIED PHYSICS, JAPANESE JOURNAL OF APPLIED PHYSICS, 53(5), 05FB21-1 - 05FB21-6, May 2014 , Refereed
    Summary:To clarify the bonding mechanism for the plasma-irradiated PET films and the origin of the long lifetime of the bonding ability, we soaked the irradiated films in various types of liquid reagent, then tried to bond them by heat-pressing. The irradiated films do not lose the bonding ability after soaking in water, acid, alkali, and organic solvents, whereas they lose it after soaking in ionic solutions of AlCl3 and FeCl3. The COOH is created on the surface by the irradiation, but it is consumed by the chemical reaction with Al and Fe ions. This is the origin of the inactivation of the irradiated surface and the disappearance of the bonding ability after the soaking. The result supports our proposal of "dehydrated condensation reaction" concerning COOH as the bonding mechanism. The irradiated films should be stable in a normal atmosphere for a long time because they are not subjected to water, acid, alkali, and organic solvents. c 2014 The Japan Society of Applied Physics
  • Preparation of [100] oriented SrTiO3 thin films on flexible polymer sheets, Hiroaki Nishikawa, Yusuke Morita, Masanobu Kusunoki, Shigeki Hontsu, Hidekazu Tanaka, Tamio Endo, JAPANESE JOURNAL OF APPLIED PHYSICS, JAPANESE JOURNAL OF APPLIED PHYSICS, 53(5), 05FB06-1 - 05FB06-4, May 2014 , Refereed
    Summary:In this study, we prepared a uniaxially oriented oxide on a flexible polymer substrate. We first grew [100] oriented SrTiO3 (STO) on a MgO(100) substrate. After bonding the STO film to a poly(ethylene naphthalete) (PEN) sheet with a photoresist, we etched the MgO substrate with a phosphoric acid solution to transfer the oxide film to the PEN sheet. The thin (300nm) STO films did not crack after release, even after bending the sheet around a rod with a 1cm radius, while the thicker (800 nm) films did. Ultimately, this process could be adapted to prepare a flexible epitaxial oxide. (C) 2014 The Japan Society of Applied Physics
  • Control of crystallinity of hydroxyapatite sheet, M. Kusunoki, T. Matsuda, N. Fujita, Y. Sakoishi, R. Iguchi, S. Hontsu, H. Nishikawa, T. Hayami, Key Engineering Materials, Key Engineering Materials, 583, 47 - 50, 2014 , Refereed
    Summary:A technique to control the crystallinity of hydroxyapatite (HA) was investigated for applications such as dentistry, regenerative medicine, cell culture scaffolding, and bio-sensors. An amorphous HA film was first produced by pulsed laser deposition. After deposition, it was separated from a substrate as a free-standing sheet. Annealing was then performed to control the crystallinity of the sheet. It was found that conventional annealing in an electric oven was not suitable for HA sheets, because it led to curling and cracking. Since such problems were assumed to be caused by thermal stress, annealing was next carried out with the HA sheet enclosed in HA powder in the center of a metal capsule. This method allowed annealing to be successfully carried out without causing any curling or cracking. Uniform pieces with dimensions of 10 mm × 10 mm cut from a large HA sheet were annealed at temperatures of 200 to 800 °C and then examined using X-ray diffraction. It was found that the intensity of the diffraction peaks associated with crystalline HA changed with annealing temperature, and that the strongest peaks were observed for the sample annealed at 500 °C. These results indicate that the crystallinity of the HA sheet can be controlled using the proposed method. © (2014) Trans Tech Publications, Switzerland.
  • C-Axis-Oriented Hydroxyapatite Film Grown Using ZnO Buffer Layer, Yasuhiro Sakoishi, Ryo Iguchi, Hiroaki Nishikawa, Shigeki Hontsu, Takashi Hayami, Masanobu Kusunoki, APPLIED PHYSICS EXPRESS, APPLIED PHYSICS EXPRESS, 6(11), 115501-1 - 115501-3, Nov. 2013 , Refereed
    Summary:A method of fabricating c-axis-oriented hydroxyapatite film on a quartz crystal microbalance (QCM) sensor was investigated. ZnO was used as a template to obtain a hexagonal hydroxyapatite crystal of uniaxial orientation. The ZnO was grown as a c-axis film on a Au/quartz with the surface structure of a QCM sensor. Under optimized conditions, hydroxyapatite was deposited by pulsed laser deposition. X-ray diffraction showed the hydroxyapatite film to be oriented along the c-axis. Because Au and ZnO are applied to many devices, the anisotropic properties of hydroxyapatite may be incorporated into these devices as well as QCM sensors. (C) 2013 The Japan Society of Applied Physics
  • Adhesive Strength between Flexible Hydroxyapatite Sheet and Tooth Enamel, E. Yamamoto, N. Kato, H. Nishikawa, M. Kusunoki, T. Hayami, K. Yoshikawa, S. Hontsu, BIOCERAMICS 24, BIOCERAMICS 24, 529-530, 522 - +, 2013 , Refereed
    Summary:Tooth enamel cannot be reconstructed once it is destroyed immoderately. Hydroxyapatite (HAp) thin sheet can potentially be used for a novel dental biomaterial to repair the enamel. Using a pulsed laser deposition (PLD) method, we have successfully created a flexible HAp sheet of less than a few micrometers in thickness. Due to its flexibility, the HAp sheet is tightly adhered on curved surfaces at the target site. In the present study, we newly developed double-layered sheets composed of HAp film coated with tricalcium phosphate (TCP) thin layer. The HAp/TCP sheet was adhered to the extracted human teeth using a calcium phosphate solution for 3 days. The adhesive strength between the HAp/TCP sheet and tooth enamel was evaluated by quasi-static tensile tests. Moreover, the interface structure between them was observed by a scanning electron microscopy. As a result of the mechanical evaluation, the adhesive strength was greater than approximately 2.5 MPa. The electron microscopic observation revealed that the sheet was partially fused with the enamel. These findings suggest the possibility that enamel defects are repaired using the HAp/TCP sheet for a short duration.
  • Long Lifetime of Plasma Effect on Bonding of Poly(ethylene terephthalate) Films and Surface Analyses, Miyoshi Yokura, Kazuya Hanada, Kenichi Uehara, Yuichi Nakamura, Lakshmi Sanapa Reddy, Hiroaki Nishikawa, Masatsugu Nagashima, Tamio Endo, JAPANESE JOURNAL OF APPLIED PHYSICS, JAPANESE JOURNAL OF APPLIED PHYSICS, 51(11), 11PG14-1 - 11PG14-6, Nov. 2012 , Refereed
    Summary:Poly(ethylene terephthalate) (PET) films can be bonded directly by oxygen plasma irradiation and heat press at low temperatures of 100-160 degrees C. The irradiated films were kept in the atmosphere for six years, yet they can be bonded tightly. The irradiated surface is extremely active just after the irradiation, and it is considerably active after five years. Dry- and wet-peel tests suggest hydrogen bonding and chemical bonding. The films are bonded by these two elements at lower press temperatures, while by the pure chemical bonding at higher temperatures. Fourier transform infrared spectroscopy (FTIR) results on the non-irradiated, irradiated and bonded samples indicate that OH and COOH groups are created at the surface, they are responsible for the both bondings. Dehydrated condensation reaction is proposed for the chemical bonding. The hydrogen bonding is broken by water penetration, causing smaller peel strength under the wet-peel test. Cross-linking layer may be the origin for the long lifetime. (C) 2012 The Japan Society of Applied Physics
  • Fabrication of hydroxyl apatite coating titanium web scaffold using pulsed laser deposition method, Shigeki Hontsu, Yoshiya Hashimoto Dr., Yoshihiro Yoshikawa, Masanobu Kusunoki, Hiroaki Nishikawa, Akihiro Ametani, Journal of Hard Tissue Biology, Journal of Hard Tissue Biology, 21(2), 181 - 188, 2012 , Refereed
    Summary:To develop an improved surface conformation of titanium web (TW) scaffold, we examined the in vitro and in vivo biocompatibility of a thin hydroxyapatite (HA) deposited by pulsed laser ablation. Thin HA film was deposited on titanium discs using an pulsed laser operating at a repletion rate of 10 Hz and annealed by heating at 380°C for 1 h. The presence of HA not only along the surface but also in the TW inner region was confirmed by the elementary mapping of calcium, phosphorous, and titanium. X-ray diffraction pattern showed that crystalline HA was present in the HA coating. Microscopic images after actin staining with rhodamine phalloidin revealed that the spread of clonal stromal cells was markedly greater on HA coating than on untreated TW. When infused with clonal stromal cells, the HA-coated TW could indeed generate bone formation in the backs of nude mice. However, the appearance of new bone was not enhanced by the HA coating, likely because air in the porous scaffold during cell loading reduces the cell-scaffold contact. Mild vacuum loading techniques might enable differences of osteo-differentiation between HA-coated TW and non-coated TW to emerge. © 2012 The Hard Tissue Biology Network Association Printed in Japan, All rights reserved.
  • Fabrication of very thin high-temperature-superconducting films required for high-sensitivity optics/superconductivity converters, Daisuke Ito, Katsumi Kotani, Tomoki Miyake, Hiroaki Nishikawa, Shigeki Hontsu, Masanobu Kusunoki, IEEJ Transactions on Electronics, Information and Systems, IEEJ Transactions on Electronics, Information and Systems, 132(11), 1722 - 1726, 2012 , Refereed
    Summary:We studied a method to obtain superconductivity even in very thin films of YBa2Cu3Oy (YBCO). These thinner YBCO films will be able to be applied to optics/superconductivity (opt/super) converters with high optical sensitivity. Opt/super converters composed of YBCO nano-bridges or nano-wires require a low critical current that is determined by the film thickness. According to X-ray diffraction, critical temperature (Tc) and residual resistivity ratio for the substrates of MgO (100), SrTiO 3 (100) and NdGaO3 (110), superconducting features are influenced by the lattice mismatching layer in YBCO closing to a hetero-epitaxy interface between YBCO and single crystal substrate. YBCO films with different thicknesses varying from 80 to 10 nm were prepared on SrTiO3, using a suitable temperature. The values of Tc slightly decreased when reducing YBCO thickness from 80 to 20 nm, and then declined sharply at less than 20 nm. It is considered that a layer in the beginning of deposition less than 20 nm causes stress in the crystal lattice. The Tc of 20 nm YBCO film on SrTiO3 was 80.8 K. It can work above liquid N2 temperature. © 2012 The Institute of Electrical Engineers of Japan.
  • Regeneration of tooth enamel by flexible hydroxyapatite sheet, S. Hontsu, N. Kato, E. Yamamoto, H. Nishikawa, M. Kusunoki, T. Hayami, K. Yoshikawa, Key Engineering Materials, Key Engineering Materials, 493-494, 615 - 619, 2012 , Refereed
    Summary:Before a tooth erupts, the ameloblasts are lost, which means that the tooth enamel does not regenerate itself after tooth eruption. In the present study, we attempt to regenerate the tooth enamel artificially using a flexible hydroxyapatite (HAp) sheet. First, a HAp film was deposited on a soluble substrate by pulsed laser deposition (PLD) using an ArF excimer laser. Next, the HAp film was collected as a freestanding sheet by dissolving the substrate using a solvent. The HAp sheet was adhered to the extracted human teeth using a calcium phosphate solution. The variation of the crystal structure of the HAp sheet with time was investigated by X-ray diffraction analysis. Furthermore, the variation in the mechanical characteristics with time between the HAp sheet and dental enamel were evaluated using tensile and scratch tests. The results suggest that the HAp sheet became fused to the tooth enamel within approximately one week. © (2012) Trans Tech Publications.
  • Osteoconduction of a stoichiometric and bovine hydroxyapatite bilayer-coated implant, Takashi Hayami, Shigeki Hontsu, Yuichi Higuchi, Hiroaki Nishikawa, Masanobu Kusunoki, CLINICAL ORAL IMPLANTS RESEARCH, CLINICAL ORAL IMPLANTS RESEARCH, 22(7), 774 - 776, Jul. 2011 , Refereed
    Summary:Objective: To impart rapid and durable osteoconductivity to implants, a commercial titanium screw implant was coated with stoichiometric hydroxyapatite (HA; 50 nm thick), and then with bovine hydroxyapatite (B-HA; 300 nm thick) using the pulsed laser deposition technique. As control specimens, a commercial implant coated with HA (20 mu m thick) using the flame spraying method (sprayed implant) and a simple titanium implant (basic implant) was used. Methods: The osteoconductivities of these three types of implant, after implantation for 4-24 weeks, were histologically evaluated. Results: Peeling of HA from the sprayed implant was observed by scanning electron microscopic observation. In the fourth postoperative week, the bilayered implant was already closely adhered to bone. On the other hand, the basic implant was surrounded by a gap containing connective tissue. With the sprayed implant, the bone adhered to the thick HA coating. Conclusion: The bilayer deposition technique supplies quick and long-term fixation of implants to bone, because the B-HA film dissolves to aid osteoconduction right immediately after implantation and the HA thin film maintains osteoconduction without dissolution. Neither of the thin-film fractures easily compared with thick coatings.
  • Fabrication of a Large Hydroxyapatite Sheet, Masanobu Kusunoki, Yoshiaki Kawakami, Taiyo Matsuda, Hiroaki Nishikawa, Takashi Hayami, Shigeki Hontsu, APPLIED PHYSICS EXPRESS, APPLIED PHYSICS EXPRESS, 3(10), 100073-1 - 100073-3, 2010 , Refereed
    Summary:A large hydroxyapatite (HA) sheet of 50 mm diameter was constructed using a new fabrication process. The HA sheet was prepared by pulsed laser deposition (PLD) and then separated from the substrate. An intermediate layer of spin-coated photoresist between the PLD film and the substrate was dissolved in acetone to enable the separation. Sufficient crystallinity was obtained after postannealing. The area of the HA sheet prepared by the proposed process was approximately 20 times larger than that of the HA sheet prepared by the previous process. The proposed process can also be used for larger sheets. The HA sheet has promise in medical and dental applications. (C) 2010 The Japan Society of Applied Physics
  • Strong uniaxial in-plane magnetic anisotropy of (001)- and (011)-oriented La0.67Sr0.33MnO3 thin films on NdGaO3 substrates, H. Boschker, M. Mathews, E. P. Houwman, H. Nishikawa, A. Vailionis, G. Koster, G. Rijnders, D. H. A. Blank, PHYSICAL REVIEW B, PHYSICAL REVIEW B, 79(21), 214425, Jun. 2009 , Refereed
    Summary:Epitaxial La0.67Sr0.33MnO3 (LSMO) ferromagnetic thin films were coherently grown on NdGaO3 (NGO) substrates with different crystal orientations of the surface plane. On the (110)(o)- and (001)(o)-oriented substrates, the film grows in the (001)(pc) orientation, and on the (100)(o)-, (010)(o)-, and (112)(o)-oriented substrates the film is (011)(pc) oriented (we will use subindices o and pc for the orthorhombic and pseudocubic crystal structures, respectively). The lattice parameters and pseudocube angles of the deformed LSMO pseudocube have been determined from x-ray diffraction measurements. The in-plane magnetic easy and hard directions of these films have been determined from the dependence of the remnant magnetization on the angle of the in-plane applied field. For all substrate orientations there is a strong in-plane uniaxial magnetic anisotropy, determined by the crystal directions of the substrate surface. The easy and hard magnetic-anisotropy directions are explained consistently by the (bulk) inverse magnetostriction model, except for the film on NGO (112)(o).
  • Rotation of the magnetic easy axis in La0.67Sr0.33MnO3 thin film on NdGaO3(112), Hiroaki Nishikawa, Evert Houwman, Hans Boschker, Mercy Mathews, Dave H. A. Blank, Guus Rijnders, APPLIED PHYSICS LETTERS, APPLIED PHYSICS LETTERS, 94(4), 042502, Jan. 2009 , Refereed
    Summary:The in-plane magnetic anisotropy is studied for pseudocubic {011}(pc) oriented La0.67Sr0.33MnO3 (LSMO) thin film grown on orthorhombic NdGaO3(NGO)(112)(o) (the subindices "pc" and "o" indicate the pseudocubic and orthorhombic lattice structure, respectively). The direction of the in-plane remanent magnetization of LSMO thin films with different thicknesses is determined. With increasing film thickness the easy axes rotate and the anisotropy changes from uniaxial to biaxial. This is associated with the increasing symmetry of the LSMO with increasing thickness, starting with a monoclinic LSMO structure at the nonrectangular NGO(112)(o) surface unit cell of the substrate, developing into an orthorhombic structure at the top part of the thickest films.
  • Preparation of freestanding hydroxyapatite membranes with excellent biocompatibility and flexibility, Hiroaki Nishikawa, Ryota Hatanaka, Masanobu Kusunoki, Takashi Hayami, Shigeki Hontsu, APPLIED PHYSICS EXPRESS, APPLIED PHYSICS EXPRESS, 1(8), 088001-1 - 088001-3, Aug. 2008 , Refereed
    Summary:Hydroxyapatite (HAp) is one of the most widely used materials for tissue culture scaffolding in regenerative medicine. To apply HAp as a suitable material for tissue culture scaffolding, we have developed freestanding HAp membranes that can be directly transplanted "as is" into a diseased site after tissue culturing. These freestanding HAp membranes are highly biocompatible, provide early cell proliferation and differentiation, and their flexibility allows some degree of configuration to the target site. This tissue culture scaffold is ideal from the standpoint of harvesting tissue and directly transplanting it to the diseased site. (C) 2008 The Japan Society of Applied Physics.
  • Cytocompatibility of calcium phosphate coatings deposited by an ArF pulsed laser, Y. Hashimoto, M. Kawashima, R. Hatanaka, M. Kusunoki, H. Nishikawa, S. Hontsu, M. Nakamura, JOURNAL OF MATERIALS SCIENCE-MATERIALS IN MEDICINE, JOURNAL OF MATERIALS SCIENCE-MATERIALS IN MEDICINE, 19(1), 327 - 333, Jan. 2008 , Refereed
    Summary:In the current studies, we deposited ultra-thin hydroxyapatite films on a pure titanium substrate by pulsed laser deposition, and we examined the effects of these surfaces on rat bone marrow (RBM) cells. This method allowed deposition of 500-, 2,000-, and 5,000-angstrom-thick hydroxyapatite films. X-ray diffraction showed that the amorphous films recrystallized to a hydroxyapatite crystal structure after annealing. The proliferation of RBM cells was unaffected by the hydroxyapatite films, but osteocalsin and alkaline phosphatase mRNA and protein levels were elevated in cells grown on 2,000- and 5,000-angstrom-thick films. These results indicate that ultra-thin hydroxyapatite films generated by pulsed laser deposition are better at promoting osteogenesis than pure titanium surfaces.
  • Cytocompatibility of calcium phosphate coatings deposited by an ArF pulsed laser, Y. Hashimoto, M. Kawashima, R. Hatanaka, M. Kusunoki, H. Nishikawa, S. Hontsu, M. Nakamura, JOURNAL OF MATERIALS SCIENCE-MATERIALS IN MEDICINE, JOURNAL OF MATERIALS SCIENCE-MATERIALS IN MEDICINE, 18(7), 1457 - 1464, Jul. 2007 , Refereed
    Summary:In the current studies, we deposited ultra-thin hydroxyapatite films on a pure titanium substrate by pulsed laser deposition, and we examined the effects of these surfaces on rat bone marrow (RBM) cells. This method allowed deposition of 500-, 2000-, and 5000-angstrom-thick hydroxyapatite films. X-ray diffraction showed that the amorphous films recrystallized to a hydroxyapatite crystal structure after annealing. The proliferation of RBM cells was unaffected by the hydroxyapatite films, but osteocalsin and alkaline phosphatase mRNA and protein levels were elevated in cells grown on 2000- and 5000-angstrom-thick films. These results indicate that ultra-thin hydroxyapatite films generated by pulsed laser deposition are better at promoting osteogenesis than pure titanium surfaces.
  • Imparting cell adhesion to poly(vinyl alcohol) hydrogel by coating with hydroxyapatite thin film, Takashi Hayami, Kazuaki Matsumura, Masanobu Kusunoki, Hiroaki Nishikawa, Shigeki Hontsu, MATERIALS LETTERS, MATERIALS LETTERS, 61(13), 2667 - 2670, May 2007 , Refereed
    Summary:To impart good cell adhesion to poly(vinyl alcohol) hydrogel (PVA-H) as an artificial articular cartilage, hydroxyapatite thin film 300 nm thick was deposited by a pulsed laser deposition technique on PVA-H, which has virtually no cell adhesion. A cell culture method was used to study the effect of hydroxyapatite deposition on PVA-H upon cell adhesion among mouse fibroblasts. The cell adhesion of water content 33% PVA-H coated with the amorphous hydroxyapatite film showed a maximum as high as that of commonly used tissue culture dishes. This technique was also effective for improving cell adhesion, even on a higher water content (53%) PVA-H. This is a novel technique to improve the biocompatibility and attachment of PVA-H and with the underlying bone and natural cartilage. (C) 2006 Elsevier B.V. All rights reserved.
  • Designing coplanar superconducting lumped-element bandpass filters using a mechanical tuning method, S Hontsu, K Agemura, H Nishikawa, M Kusunoki, IEICE TRANSACTIONS ON ELECTRONICS, IEICE TRANSACTIONS ON ELECTRONICS, E89C(2), 151 - 155, Feb. 2006 , Refereed
    Summary:A coplanar type lumped-element 6-pole microwave Chebyshev bandpass filter (BPF) of center frequency (f(0)) 2.0 GHz and fractional bandwidth (FBW) 1.0% was designed. For the design method, theory of direct coupled resonator filters using K-inverters was employed. Coplanar type lumped-element BPFs are composed of a meander-line L and interdigital C elements. The frequency response was simulated and analyzed using an electromagnetic field simulator (Sonnet-EM). Further, the changes in fo and FBW of the BPF were also realized by the mechanical tuning method.
  • Mechanical tuning of superconducting lumped element filter, S Hontsu, K Iguchi, K Agemura, H Nishikawa, M Kusunoki, IEEE TRANSACTIONS ON APPLIED SUPERCONDUCTIVITY, IEEE TRANSACTIONS ON APPLIED SUPERCONDUCTIVITY, 15(2), 972 - 975, Jun. 2005 , Refereed
    Summary:The tunable filter has variable center frequency (f(o)) and variable bandwidth (BW) that can be adapted to software defined radio. In our mechanical tunable filter, capacitance of each element is changed by motion of dielectric plate that is located above the capacitive elements. The dielectric plates are moved by piezoelectric bimorph actuators. Tuning test of the fo in a cryocooler is performed using an actual superconducting filter fabricated with YBa2Cu3Oy thin film deposited on an MgO (100) substrate. Taking into account of the effective change of parallel capacitance to ground plane by movement of dielectric plates above the element, we choose the coplanar wave guide type filter that has the ground plane on top side of the substrate. Suitable design of the mechanically tunable superconducting lumped element filter is discussed.
  • Protein adsorption on patterned hydroxyapatite thin films fabricated by pulsed laser deposition, M Kusunoki, M Kawasima, H Nishikawa, K Morimoto, T Hayami, S Hontsu, T Kawai, JAPANESE JOURNAL OF APPLIED PHYSICS PART 2-LETTERS & EXPRESS LETTERS, JAPANESE JOURNAL OF APPLIED PHYSICS PART 2-LETTERS & EXPRESS LETTERS, 44(8-11), L326 - L327, 2005 , Refereed
    Summary:Protein adsorption on hydroxyapatite (HAP) thin film was investigated before and after patterning. Hydroxyapatite thin film 100 nm thick was deposited by pulsed laser deposition. The film was patterned by photolithography and wet etching with HCl solution. Proteins (phospholyrase b, bovine serum albumin, and others) labeled with fluorescein isothiocyanate (FITC) were used as the reagent. After the HAP film was soaked in the reagent and washed with pure water, a conspicuous contrast in FITC was observed between the HAP pattern and the glass substrate (or photoresist). This behavior showed that the biocompatibility of the HAP thin film was not influenced by the patterning process. Our technique for HAP thin film is adaptable for applications involving biosensors as electronic devices and scaffolds for tissue culture.
  • Error in surface resistance originating from the dielectric loss of the parallel-plate dielectric resonator using the two-resonators method, M Kusunoki, H Nishikawa, S Hontsu, PHYSICA C-SUPERCONDUCTIVITY AND ITS APPLICATIONS, PHYSICA C-SUPERCONDUCTIVITY AND ITS APPLICATIONS, 412, 1524 - 1527, Oct. 2004 , Refereed
    Summary:An error in surface resistance (R-s) originating from the dielectric loss (tan delta) of the parallel plate dielectric resonator using the two-resonators method is investigated. In the two-resonators method, the error in R-s(DeltaR(s)) due to the difference in tan delta(Delta tan delta) between the TE011 and TE01n mode rods is examined, considering the actual scattering of values of tan delta among sapphire rods. Taking this scattering into account, the projected value of DeltaR(s) cannot be disregarded for general R-s values (about 0.1 mOmega) of HTS films. As a comparative simulation, the case of a single resonator was also considered where the tan delta is neglected in the estimate of R-s. Due to the uncertainty and complexity in the two-resonators method, this method is not so superior to the single-rod resonator measurement by neglecting tan 6 at higher resonance frequency. (C) 2004 Elsevier B.V. All rights reserved.
  • Preparation and design of a mechanically tunable superconducting lumped-element filter, S Hontsu, S Mine, H Nishikawa, M Nakamori, A Fujimaki, T Kawai, SUPERCONDUCTOR SCIENCE & TECHNOLOGY, SUPERCONDUCTOR SCIENCE & TECHNOLOGY, 17(5), S255 - S258, May 2004 , Refereed
    Summary:We have proposed a novel type of tunable superconducting microwave filter consisting of planar lumped elements which can independently change their centre frequency, bandwidth and skirt characteristics. The independent control is realized by applying the technique of mechanical tuning to the interdigital capacitors C which constitute the filter. We design a three-pole Chebyshev band-pass filter (BPF) with a centre frequency of 6 GHz, 3 dB fractional bandwidth (FBW) of 1.67% and passband ripple of 0.1 dB. The values of C and the meander line inductor L element are calculated using an electromagnetic simulator. The designed filter is fabricated using YBa2Cu3O7-delta (YBCO) film deposited on a MgO(100) substrate (10 mm x 10 mm x 0.5 mm). The measured transmission characteristic shows the typical BPF-like frequency dependence. This result is the first report on the planar lumped-element BPF with a high frequency of 6 GHz. Furthermore, the large shift of the centre frequency of the order of a gigahertz is obtained by an experiment in the mechanical tuning method.
  • Study of mechanically tunable superconducting microwave filter using lumped elements, S Hontsu, S Mine, H Nishikawa, M Nakamori, A Fujimaki, M Inoue, A Maehara, T Kawai, IEEE TRANSACTIONS ON APPLIED SUPERCONDUCTIVITY, IEEE TRANSACTIONS ON APPLIED SUPERCONDUCTIVITY, 13(2), 720 - 723, Jun. 2003 , Refereed
    Summary:We propose a mechanically tunable superconducting microwave filter based on lumped elements composed of planar meander-line inductors (L) and inter-digital capacitors (C). As the first step, we have designed and evaluated a 3-pole Chebyshev bandpass filters with lumped elements using a circuit simulator. It is found that the center frequency, bandwidth and skirt rejection of the filter can be controlled by changing only the capacitance. The L and C elements values are estimated using an electromagnetic simulator. Furthermore, we have fabricated the inter-digital capacitor designed with the above procedure. We have evaluated change of the C values using mechanical tuning as a step toward a tunable superconducting microwave filter.
  • Preparation of perovskite type manganite on Al2O3 substrate as an excellent buffer layer for YBa2Cu3O7-delta growth, H Nishikawa, S Hontsu, M Nakamori, H Tabata, T Kawai, IEEE TRANSACTIONS ON APPLIED SUPERCONDUCTIVITY, IEEE TRANSACTIONS ON APPLIED SUPERCONDUCTIVITY, 13(2), 2725 - 2728, Jun. 2003 , Refereed
    Summary:The perovskite type ferromagnetic manganite Pr0.8Ca0.2MnO3 (PCMO) buffer layers for superconducting microwave devices were examined in order to allow Al2O3 single crystal to be used as a substrate for YBa2Cu3O7-delta (YBCO) growth and to provide functionality for microwave devices. The use of magnetic buffer layers with YBCO is effective to magnetically controllable superconducting microwave devices. The (0001) surface of the Al2O3 and [113]-oriented YBCO are used in this study due to the similarity of ion configurations at the interface. YBCO grown on the PCMO buffer shows a critical temperature of 87.5 K. The straight line of YBCO grown on the Al2O3 (0001) buffered by the PCMO shows relatively good transmission property with the, insertion loss of less than 0.7 dB below 70 K measured at 2 GHz. These results indicate that PCMO is a suitable magnetic buffer layer for YBCO growth on Al2O3 (0001).
  • Characteristics of mechanically tunable superconductive resonators, S Mine, M Terakago, T Sakatani, S Hontsu, H Nishikawa, A Fujimaki, M Nakamori, H Tabata, T Kawai, SUPERCONDUCTOR SCIENCE & TECHNOLOGY, SUPERCONDUCTOR SCIENCE & TECHNOLOGY, 15(4), 635 - 638, Apr. 2002 , Refereed
    Summary:In order to realize superconductive microwave devices with large tuning characteristics, we have studied a mechanically tunable superconductive resonator beneath a dielectric and/or magnetic floating plate (FP) as a first step. The resonator consists of a half-wavelength coplanar waveguide (CPW). The principle of the mechanically tunable method is that variations of the effective permittivity and/or the effective permeability for the microwave waveguide line can be obtained by changing the distance between the resonator and the FP. In computer simulations of electromagnetic fields for the mechanically tunable half-wavelength CPW resonator, we have obtained a large shift of the resonant frequency with a band of 1.75 GHz to 7 GHz (tunability is approximately 25%) using the (La0.3Sr0.7)(Al0.65Ta0.35)O-3 (LSAT) single crystal (dielectric constant (epsilon(r)) = 22.8, loss tangent (tandelta) = 1.7 x 10(-4)) as the FP. Based on the results, we have performed an experiment using a half-wavelength CPW resonator made from YBa2Cu3O7-delta thin film and the LSAT FP. The result shows a drastic resonant frequency shift of approximately 1.36 GHz (tunability is approximately 20%) when the LSAT FP is moved, using an electromagnetic actuator. In this experiment, it is also noted that the insertion loss is quite low, less than 0.8 dB, compared to previous reports for various tunable filters. Moreover, we have also measured the tuning characteristics with a TiO2 single crystal (epsilon(r) = 85.4, tandelta = 2.5 x 10(-4)) as the FP. As a result, we have obtained quite large tuning characteristics of approximately 2 GHz (tunability is approximately 28%).
  • Preparation of directly stacked YBa2Cu3O7-delta/oxide magnetic material thin films on Al2O3(0001) substrate, H Nishikawa, S Hontsu, T Sakatani, M Nakamori, M Terakago, S Mine, H Tabata, T Kawai, SUPERCONDUCTOR SCIENCE & TECHNOLOGY, SUPERCONDUCTOR SCIENCE & TECHNOLOGY, 15(1), 170 - 173, Jan. 2002 , Refereed
    Summary:The incorporation of magnetic material buffer layers for superconducting microwave devices is examined in order to allow Al2O3 single crystal to be used as a substrate for YBa2Cu3O7-delta (YBCO) growth and to provide functionality for microwave devices. Two magnetic materials are examined; Ni0.35Zn0.65Fe2O4 (NZFO), which is a spinel-type ferrite, and Pr0.8Ca0.2MnO3 (PCMO), a perovskite-type ferromagnetic material. The use of magnetic buffer layers with YBCO is applicable to magnetically controllable superconducting microwave devices. The (0001) surface of the Al2O3 and [113]-oriented YBCO are used in this study due to the similarity of ion configuration at the interface. YBCO grown on Al2O3(0001) buffered with NZFO does not exhibit superconducting behaviour, whereas that grown on the PCMO buffer superconducts at a critical temperature of 87.5 K. This result indicates that PCMO is a suitable magnetic buffer layer for YBCO growth on Al2O3(0001).
  • Mechanism for excimer-laser ablation in alkaline-earth metals, H Nishikawa, M Kanai, G Szabo, T Kawai, PHYSICAL REVIEW B, PHYSICAL REVIEW B, 61(2), 967 - 973, Jan. 2000 , Refereed
    Summary:The time-of-flight distribution and the amount of desorbed monovalent ion were measured for laser ablation of alkaline-earth metals. The experiment is performed using two wavelengths (193-nm ArF excimer laser and 248-nm KrF excimer laser), a fluence of less than 500 mJ/cm(2) and an effective pulse duration of 14-20 ns. Ion desorption occurs at a lower fluence than that predicted by a thermal evaporation model. The relationship between the amount of desorbed ion and the fluence shows highly nonlinear behavior. Based on the obtained results, a model is proposed in which the laser ablation of alkaline-earth metals is caused by the core electron ionization via the multiphoton photochemical process.
  • Preparation of all-oxide ferromagnetic/ferroelectric/superconducting heterostructures for advanced microwave applications, Shigeki Hontsu, Hiroaki Nishikawa, Harutaka Nakai, Junya Ishii, Masaya Nakamori, Akira Fujimaki, Yasumasa Noguchi, Hitoshi Tabata, Tomoji Kawai, Superconductor Science and Technology, Superconductor Science and Technology, 12(11), 836 - 839, Nov. 1999 , Refereed
    Summary:As candidates for functional layers. 3d transition metal oxides with perovskite structures show some interesting properties, such as ferromagnetism, ferroelectricity and superconductivity. Accordingly, combinations of these properties can be used to create new tunable microwave devices. Ferromagnetic/ferroelectric/superconducting multistructures, such as La0.70Sr0.30MnO3 (LSMO)/Pb(Zr0.52Ti0.48)O3 (PZT)/YBa2Cu3O7-y (YBCO) and YBCO/PZT/LSMO, have been fabricated by ArF excimer laser deposition on LaSrGaO4 (LSGO) [001] and (La0.30Sr0.70)(Al0.65Ta0.35)O3 (LSAT) [001] substrates. The resulting trilayer films have a highly c-axis oriented structure. Epitaxial YBCO films formed on PZT/LSMO//LSAT have a zero-resistance temperature of 87 K. Moreover, D-E and M-H hysteresis loop are observed for the LSMO/PZT/YBCO//LSGO structure using a conventional Sawyer-Tower circuit and a superconducting quantum interference device (SQUID). The remanent polarization and coercive field of the PZT layer are found to be 19 μC cm-2 and 275 kV cm-1 at 70 K, respectively. The remanent magnetic moment and coercive magnetic field are about 2.6 μB/site and 50 Oe respectively at 78 K. Furthermore, the microwave surface resistance (RS) (22 GHz) of the YBCO film in the YBCO/PZT/LSMO structure was 1.32 mΩ at 77 K. These results suggest that LSMO/PZT/YBCO structures are favourable for use in superconducting microwave applications such as tunable phaseshifters and filters.
  • Modification of cleaved surfaces of Bi2Sr2CaCu2O8 single crystals induced by ArF excimer laser irradiation, Kawayama, I, JJ Dubowski, H Nishikawa, T Kawai, APPLIED SURFACE SCIENCE, APPLIED SURFACE SCIENCE, 143(1-4), 313 - 318, Apr. 1999 , Refereed
    Summary:The variation of surface morphology and chemical composition of cleaved surfaces of (001) Bi2Sr2CaCu2O8 (BSCCO) crystals was investigated following irradiation in vacuum with an ArF excimer laser. Results were obtained for laser fluences in the range from 20 to 500 mJ/cm(2). Distinctive surface structures of BSCCO have been observed having a strong correlation with the laser fluence and number of pulses delivered to the site. The development of a relatively smooth surface (delta similar to 20 nm) has been observed for irradiation at 500 mJ/cm(2). The formation of a 'hexatic' micro-structure on the surface of ablated crystals suggests that a two-dimensional phase transition has occurred, At lower laser fluences, rough surfaces (0.05 mu m < delta < 3 mu m) were developed with characteristic pyramids and/or cone-shape islands. The results indicate that surface modification is due to different mechanisms corresponding to the surface temperature being raised by direct laser irradiation and laser heated plasma. (C) 1999 Elsevier Science B.V. All rights reserved.
  • Heteroepitaxy of perovskite-type oxides on oxygen-annealed SrTiO3(1 0 0) important factors for preparation of atomically flat oxide thin films, Hiroaki Nishikawa, Masaki Kanai, Tomoji Kawai, Journal of Crystal Growth, Journal of Crystal Growth, 179(3-4), 467 - 476, 1997 , Refereed
    Summary:Thin film growth of perovskite-type oxides, CaTiO3 and La0.7Sr0.3MnO3, on atomically smooth SrTiO3(1 0 0) substrate has been studied by in-situ reflection high-energy electron diffraction (RHEED) and ex-situ atomic force microscope (AFM) in order to understand the key points to keep the surface flatness. It is found out that the termination of substrate surface by AO layer of perovskite structure (ABO3), i.e., CaO, SrO and BaO, is quite effective to prepare the atomically flat thin films. Among these top layers, the SrO termination gives the best result. CaTiO3 film on SrTiO3(1 0 0) can keep the atomically flat surface in spite of large lattice mismatch (∼ 2.3%), while La0.7Sr0.3MnO3 needs more strict lattice matching to keep the flat surface. Structure and orientation of SrO are analyzed by only in-situ RHEED observation as the first step of real-time growth control. Furthermore, the migration process of Sr supplied by laser ablation is studied by time-resolved measurement of RHEED intensity. The growth process of thin film by laser ablation method is discussed with this experiment.
  • Laser ablation of alkaline earth metals investigated by time-of-flight mass spectroscopy: Ion desorption by core-electron excitation, H Nishikawa, M Kanai, T Kawai, JAPANESE JOURNAL OF APPLIED PHYSICS PART 2-LETTERS, JAPANESE JOURNAL OF APPLIED PHYSICS PART 2-LETTERS, 35(4A), L425 - L428, Apr. 1996 , Refereed
    Summary:The time-of-flight distribution and the amount of desorbed monovalent ions have been measured in the laser ablation of alkaline earth metals. The obtained relationship between the amount of ions and the laser fluence indicates that the desorption is caused by 5-, 4- and 3-photon processes for Ca, Sr and Ba, respectively when an ArF excimer laser is used as a light source. On the basis of the results, a model is proposed in which the laser ablation of the alkaline earth metals is triggered by excitation of the core electrons at the highest energy level.
  • Laser ablation process and growth control of oxide thin films in laser molecular beam epitaxy, T Kawai, H Nishikawa, K Koguchi, M Kanai, ADVANCED LASER PROCESSING OF MATERIALS - FUNDAMENTALS AND APPLICATIONS, ADVANCED LASER PROCESSING OF MATERIALS - FUNDAMENTALS AND APPLICATIONS, 397, 169 - 174, 1996 , Refereed
  • LASER-ABLATION MECHANISM OF SR METAL INVESTIGATED BY TIME-OF-FLIGHT MASS-SPECTROSCOPY, H NISHIKAWA, M KANAI, T KAWAI, S KAWAI, JAPANESE JOURNAL OF APPLIED PHYSICS PART 2-LETTERS, JAPANESE JOURNAL OF APPLIED PHYSICS PART 2-LETTERS, 33(8A), L1090 - L1092, Aug. 1994 , Refereed
    Summary:In order to investigate the laser ablation mechanism, the velocity distribution and amount of Sr+ produced by ArF excimer laser irradiation of Sr metal have been measured by time-of-flight (TOF) mass spectroscopy. The velocity distribution of Sr+ agrees with the Maxwell-Boltzmann distribution corrected by the center-of-mass velocity. The relationship between the amount of produced ions and laser fluence suggests that Sr+ is produced by a 4-photon process. Based on these experimental results, a simple model for the laser ablation mechanism of Sr metal is proposed.

Books etc

  • Correlated Functional Oxides: Nanocomposites and Heterostructures, H. Nishikawa, N. Iwata, T. Endo, Y. Takamura, G.-H. Lee, P. Mele, Contributor, Atomic Processes of Pulsed Laser Deposition During Growth of Alkaline Earth Oxide Thin Films, Springer,   2016 11 , 9783319437774
  • Nanocomposites, Nanostructures and Heterostructures of Correlated Oxide Systems, T. Endo, H. Nishikawa, N. Iwata, A. Bhattacharya, L. W. Martin, Joint editor, Materials Research Society,   2012 10 , 9781605114316
  • Porous Metals and Metal Foaming Technology, H. Nishikawa, T. Hayami, S. Hontsu, M. Kusunoki, Joint author, Addition of Advanced Biocompatibility to a Porous Artificial Root, p.59-p.62,   2006 02 , 4889034056

Conference Activities & Talks

  • Flexible epitaxial thin films of perovskite type oxides: The fabrication processes and the electronic properties, Hiroaki Nishikawa, Collaborative Conference on Materials Research 2019,   2019 06 , 招待有り
  • Controlling the Electronic Properties of LaMO3 (M = Mn, Fe, Co) by Electron Doping beyond the Hetero-interface with LaTiO3, Hiroaki Nishikawa, The International Conference on Optoelectronic and Nano Materials for Advanced Technology,   2019 01 , 招待有り
  • Coating Process of Epitaxial Oxide Thin Films on Flexible Substrate, Hiroaki Nishikawa, Shinji Umatani, Collaborative Conference on Materials Research 2018,   2018 06 , 招待有り
  • Characteristic Adsorption of Amino Acids on Surface of Al2O3 (0001) Single Crystal in Water Solution, Hiroaki Nishikawa, Ayaka Saito, American Physical Society 2018 March Meeting,   2018 03
  • Transfer Process of Epitaxial Functional Oxide Thin Films onto Flexible Substrates, Shinji Umatani, Hiroaki Nishikawa, American Physical Society 2018 March Meeting,   2018 03
  • Electronic Properties of Electron Transfer Heterointerface between LaFeO3 and SrTiO3, H. Nishikawa, The 15th International Union of Materials Research Society-International Conference on Advanced Materials,   2017 09
  • Transfer Process of Epitaxial Oxide Thin Films onto Flexible Polymer Sheet, H. Nishikawa, S. Kaneko, T. Endo, The 15th International Union of Materials Research Society-International Conference on Advanced Materials,   2017 08
  • Establishment of process to separate epitaxial functional oxide thin films from substrates, S. Umatani, H. Nishikawa, 4th Japan-Korea International Symposium on Materials Science and Technology 2017,   2017 08
  • Electronic properties of charge transfer heterointerface between LaFeO3 and SrTiO3, H. Nishikawa, 4th Japan-Korea International Symposium on Materials Science and Technology 2017,   2017 08 , 招待有り
  • Adsorption of amino acids on atomically flat surface of oxides in water solution, H. Nishikawa, A. Saito, 4th Japan-Korea International Symposium on Materials Science and Technology 2017,   2017 08 , 招待有り
  • Flexibilization of Epitaxial Thin Films of Perovskite Type Oxide by Using Decal Process, H. Nishikawa, M. Yokura, S. Kaneko, T. Endo, The 26th annual meeting of MRS-Japan,   2016 12
  • Specific Adsorption Behavior of Amino Acid on Al2O3 Surface, A. Saito, H. Nishikawa, International Conference on Technologically Advanced Materials and Asian Meeting on Ferroelectricity,   2016 11
  • Flexible Thin Film of Epitaxially Grown Functional Oxides, H. Nishikawa, The 3rd Korea-Japan International Symposium on Materials Science and Technology,   2016 11 , 招待有り
  • Fabrication of Epitaxial BaTiO3 Thin Film on Polymer Sheet as a Vibration Generator, H. Nishikawa, M. Yokura, S. Kaneko, T. Endo, International Conference on Technologically Advanced Materials and Asian Meeting on Ferroelectricity,   2016 11 , 招待有り
  • Electronic properties of LaFeO3/SrTiO3 heterointerface, H. Nishikawa, Global Forum on Advanced Materials and Technologies for Sustainable Development 2016,   2016 06
  • Transfer process of epitaxially grown piezoelectric BaTiO3 thin films to flexible polymer sheets, H. Nishikawa, M. Yokura, S. Kaneko, T. Endo, Global Forum on Advanced Materials and Technologies for Sustainable Development 2016,   2016 06
  • Epitaxial Thin Films of Oxide Prepared on Flexible Polymer Substrate, H. Nishikawa, M. Yokura, S. Kaneko, T. Endo, The 14th International Union of Materials Research Societies-International Conference on Advanced Materials,   2015 10 , 招待有り
  • Effect of Gas Pressure in Pulsed Laser Deposition on Chemical Composition of Hydroxyapatite Thin Films, T. Hasegawa, Y. Hashimoto, H. Nishikawa, The 14th International Union of Materials Research Societies-International Conference on Advanced Materials,   2015 10
  • Effect of concentration and pH of buffered phosphoric acid aqueous solution to surface nanostructures of Al2O3 (0001), A. Saito, T. Tsunemine, T. Makino, M. Kusunoki, H. Nishikawa, The 14th International Union of Materials Research Societies-International Conference on Advanced Materials,   2015 10
  • Dielectric properties of epitaxial hydroxyapatite thin films grown on Al2O3 (0001) substrate, H. Nishikawa, The 13th International Symposium on Sputtering and Plasma Processes,   2015 07
  • Relationship between the chemical composition and the crystallinity of hydroxyapatite thin films prepared by pulsed laser deposition, T. Hasegawa, Y. Hashimoto, H. Nishikawa, The 13th International Symposium on Sputtering and Plasma Processes,   2015 07
  • Stoichiometric Control for Hydroxyapatite Thin Film Prepared by Pulsed Laser Deposition Technique, H. Nishikawa, R. Yoshikawa, The 26th Annual Conference of the European Society for Biomaterials,   2014 09
  • Control of the Chemical Composition for Hydroxyapatite Thin Film by Pulsed Laser Deposition Technique, H. Nishikawa, R. Yoshikawa, International Union of Materials Research Societies, International Conference in Asia 2014,   2014 08
  • Filling Control of Perovskite Type Charge-transfer Insulators via Interface Electron Reconstruction from SrTiO3, H. Nishikawa, The International Union of Materials Research Societies - International Conference on Electronic Materials 2014,   2014 06 , 招待有り
  • Fabrication of Crystalized Functional Oxide Thin Films on Flexible Polymer Substrates, H. Nishikawa, Y. Morita, M. Yokura, H. Tanaka, T. Endo, The Japan Society of Applied Physics 2014 Spring Meeting,   2014 03 , 招待有り
  • Carrier doping to transition metal oxides from SrTiO3 single crystal via interface electron reconstruction, H. Nishikawa, F. Itani, The 5th Promotion Center for Global Materials Research at National Cheng Kung University Symposium,   2013 12 , 招待有り
  • Electronic Properties of Hetero-interface between LaMO3 Thin Film (M = Cr, Fe, Mn) and SrTiO3 (100) Single Crystal, H. Nishikawa, F. Itani, The 23rd Annual Meeting of MRS-Japan,   2013 12 , 招待有り
  • Photocarrier Injection into Perovskite LaMO3 (M = Fe, Co), H. Nishikawa, G. Fujihara, The 20th International Workshop on Oxide Electronics,   2013 09
  • Flexible Thin Film of Epitaxially Grown Perovskite Type Titanate, H. Nishikawa, H. Tanaka, T. Endo, M. Kusunoki, S. Hontsu, 2013 The Japan Society of Applied Physics, Materials Research Society Joint Symposia,   2013 09
  • UV control of the electric/magnetic properties of transition metal oxides grown on SrTiO3 single crystal, H. Nishikawa, The 6th IEEE/International Conference on Advanced Infocomm Technology 2013,   2013 07 , 招待有り
  • Interface Properties between LaFeO3 Thin Film and SrTiO3 Single Crystal, F. Itani, I. Kawayama, T. Kanki, M. Kusunoki, S. Hontsu, H. Tanaka, M. Tonouchi, H. Nishikawa, The Japan Society of Applied Physics 2013 Spring Meeting,   2013 03
  • Electron transfer at the interface of a Mott-Hubbard insulator LaTiO3 and a charge-transfer insulator LaFeO3, H. Nishikawa, The 2nd International Conference on Optoelectronic Materials and Thin Films for Advanced Technology,   2013 01 , 招待有り
  • Epitaxial thin films of perovskite titanate on flexible polymer materials, H. Nishikawa, Y. Morita, T. Endo, H. Tanaka, M. Kusunoki, S. Hontsu, The 19th International Workshop on Oxide Electronics,   2012 10
  • Fabrication of epitaxially grown thin films of perovskite type titanate on flexible polymer materials, H. Nishikawa, Y. Morita, T. Endo, H. Tanaka, M. Kusunoki, S. Hontsu, The Japan Society of Applied Physics 2012 Autumn Meeting,   2012 09
  • Electric and Magnetic Properties of Hetero-interface between Mott-Hubbard Insulators and Charge Transfer Insulators, H. Nishikawa, F. Itani, J.E. Kleibeuker, I. Kawayama, T. Kanki, H. Tanaka, M. Tonouchi, D.H.A. Blank, G. Rijnders, Materials Research Society 2012 Spring Meeting,   2012 04
  • Interface Charge Transfer and the Electric/Magnetic Properties of the LaFeO3/LaTiO3 Hetero Junction, H. Nishikawa, F. Itani, J.E. Kleibeuker, I. Kawayama, T. Kanki, M. Kusunoki, S. Hontsu, H. Tanaka, M. Tonouchi, D.H.A. Blank, G. Rijnders, The 21st MRS-Japan Academic Symposium,   2011 12
  • Electronic Properties of Interface in Multilayered Mott-Hubbard Insulators / Charge Transfer Insulators, H. Nishikawa, The 1st Annual World Congress of Nano-Science & Technology,   2011 10 , 招待有り
  • Transfer of epitaxial SrTiO3 thin film to flexible polymer sheet by decal process, H. Nishikawa, Y. Morita, M. Kusunoki, S. Hontsu, The 18th International Workshop on Oxide Electronics,   2011 09
  • Control of Ca/P Ratio of Hydroxyapatite Thin Film by Pulsed Laser Deposition, H. Nishikawa, R. Yoshikawa, H. Nakajima, M. Kusunoki, T. Hayami, S. Hontsu, The 24th Annual Meeting of the European Society for Biomaterials,   2011 09
  • Biocompatibility Evaluation of Hydroxyapatite-coated Titanium Fiber Mesh Scaffold, H. Nishikawa, A. Ametani, Y. Hashimoto, M. Kusunoki, T. Hayami, S. Hontsu, The 3rd International Congress on Ceramics,   2010 11
  • Epitaxial Pb(Zr0.52Ti0.48)O3 Thin Film on Flexible Polymer Material and its Piezoelectric Property for Huge Bending Stress, H. Nishikawa, Y. Morita, M. Kusunoki, S. Hontsu, The 17th International Workshop on Oxide Electronics,   2010 09
  • Synthesis of magnesium-containing apatite thin film and its biocompatibility investigated by in-vitro cell cultivation, H. Nishikawa, Y. Shinohara, Y. Hashimoto, M. Kusunoki, T. Hayami, S. Hontsu, The 11th International Conference on Ceramic Processing Science,   2010 08
  • Application of Freestanding Hydroxyapatite Membranes to Tissue Engineering, H. Nishikawa, M. Kusunoki, S. Hontsu, Special Symposium for Celebration on the 10th Anniversary of the Division of Ceramics in Medicine, Biology and Biomimetics,   2009 12
  • Epitaxial La0.67Sr0.33MnO3 Thin Film on Flexible Polymer Material, H. Nishikawa, M. Kusunoki, S. Hontsu, The16th International Workshop on Oxide Electronics,   2009 10
  • Fabrication of Biological Apatite Membranes with Various Shapes toward the Programmable Scaffolds, H. Nishikawa, Y. Hashimoto, N. Taninaka, M. Kusunoki, T. Hayami, S. Hontsu, The IUMRS International Conference in Asia 2009,   2009 06
  • Fabrication of HAp/ZnO Bilayer for Protein Sensitive Field Effect Transistor, H. Nishikawa, M. Kusunoki, S. Hontsu, Materials Research Society 2008 Fall Meeting,   2008 12
  • Uniaxial Magnetic Anisotropy of La0.67Sr0.33MnO3 Thin Films on NdGaO3 with Different Orientations Described by the Neel Anisotropy Model, H. Nishikawa, E.P. Houwman, M. Mathews, J.A. Boschker, G. Rijnders, D.H.A. Blank, The IUMRS International Conference in Asia 2008,   2008 12
  • Freestanding Hydroxyapatite Membranes with Various Shapes and the Application to Tissue Engineering Scaffolds, H. Nishikawa, R. Hatanaka, H. Asano, Y. Hashimoto, M. Kusunoki, T. Hayami, S. Hontsu, The IUMRS International Conference in Asia 2008,   2008 12
  • Asymmetry and rotation of the in-plane magnetic easy axis in La0.67Sr0.33MnO3 thin film grown on NdGaO3(112), H. Nishikawa, E. Houwman, H. Boschker, M. Mathews, G. Rijnders, D. Blank, The 15th International Workshop on Oxide Electronics,   2008 09
  • Thickness Dependence of the Magnetic Anisotropy of La0.67Sr0.33MnO3 Thin Films on NdGaO3 (112), H. Nishikawa, E.P. Houwman, J.A. Boschker, M. Mathews, G. Rijnders, D.H.A. Blank, THIOX Thin Films For Novel Oxide Devices Final Meeting,   2008 04
  • Application of epitaxial hydroxyapatite thin film as a biosensor, H. Nishikawa, H. Homma, M. Kusunoki, S. Hontsu, European MRS 2007 Spring Meeting,   2007 05
  • Preparation of hydroxyapatite sheet with various shapes and its application to programmable tissue engineering scaffold, H. Nishikawa, R. Hatanaka, M. Kusunoki, S. Hontsu, Materials Research Society 2006 Fall Meeting,   2006 11
  • Application of hydroxyapatite thin film as a biosensor, H. Nishikawa, D. Okumura, M. Kusunoki, S. Hontsu, American Physical Society 2006 March Meeting,   2006 03
  • Biosensor Consists of Na - Doped Hydroxyapatite, H. Nishikawa, M. Kusunoki, S. Hontsu, M. Kawashima, T. Kawai, American Physical Society 2005 March Meeting,   2005 03
  • Magnetoelectric properties of magnetic/ferroelectric multilayered thin film, H. Nishikawa, M. Kusunoki, S. Hontsu, T. Kawai, American Physical Society 2004 March Meeting,   2004 03
  • Superconducting Magnetostatic Wave Device Using Interaction Between Superconducting Magnetic Flux and Magnetostatic Waves, H. Nishikawa, S. Hontsu, M. Terakago, T. Kawai, The 8th IUMRS International Conference on Advanced Materials,   2003 10
  • Strain effect of the dielectric anomaly at Néel point for antiferromagnetic RCrO3 (R: La, Nd), H. Nishikawa, S. Hontsu, T. Kawai, American Physical Society 2003 March Meeting,   2003 03
  • Dielectric anomaly at Néel point in antiferromagnetic RCrO3 (R: La, Nd), T. Kubota, H. Nishikawa, S. Hontsu, T. Kawai, American Physical Society 2002 March Meeting,   2002 03
  • Heteroepitaxy of YBa2Cu3O7-d/Pr1-xCaxMnO3 on Al2O3(0001) substrate for superconducting magnetostatic wave devices, H. Nishikawa, S. Hontsu, M. Terakago, S. Mine, M. Nakamori, H. Tabata, T. Kawai, Materials Research Society 2001 Fall Meeting,   2001 11
  • Preparation of Superconducting Magnetostatic Wave Devices on Al2O3(0001) Substrate, H. Nishikawa, S. Hontsu, T. Sakatani, M. Nakamori, M. Terakago, S. Mine, H. Tabata, T. Kawai, The 8th International Workshop on Oxide Electronics,   2001 09
  • Preparation of directly stacked YBa2Cu3O7-d/oxide magnetic material thin films on Al2O3(0001) substrate, H. Nishikawa, S. Hontsu, T. Sakatani, M. Nakamori, M. Terakago, S. Mine, H. Tabata, T. Kawai, The 8th Superconductive Electronics Conference (ISEC '01),   2001 06
  • Magnetoresistance of Fe3O4/Fe3-xMxO4 (M = Co, Ni, Zn) multilayered thin films, H. Nishikawa, S. Hontsu, H. Tanaka, T. Kawai, American Physical Society 2001 March Meeting,   2001 03
  • Relationship between the localized spin configuration and the magnetoresistance of half-metallic Fe3O4, H. Nishikawa, S. Hontsu, H. Tanaka, T. Kawai, The 7th International Workshop on Oxide Electronics,   2000 10
  • Preparation of directly stacked oxide-superconductor/oxide-magnetic material thin films and their magnetic/microwave properties, H. Nishikawa, S. Hontsu, T. Sakatani, H. Tabata, T. Kawai, The 7th International Workshop on Oxide Electronics,   2000 10
  • Magnetoresistance amplification of La1-xSrxMnO3 in [111] oriented La1-xSrxMnO3/La1-ySryFeO3 superlattice, H. Nishikawa, S. Hontsu, H. Tanaka, T. Kawai, American Physical Society 2000 March Meeting,   2000 03
  • Electric and magnetic properties of (La1-xSrxMnO3)m/(La1-xSrxFeO3)n superlattice on SrTiO3(111) substrates, H. Nishikawa, S. Hontsu, T. Kawai, American Physical Society 1999 Centennial Meeting,   1999 03
  • Laser-ablation mechanism of alkaline earth metals, H. Nishikawa, M. Kanai, T. Kawai, American Physical Society 1998 March Meeting,   1998 03
  • Magnetic and transport properties of multiayered ferrite thin films, H. Nishikawa, M. Kanai, T. Kawai, American Physical Society 1998 March Meeting,   1998 03

Misc

  • Transfer Technique on Single Crystal Thin Films of Functional Oxides onto Polymer Substrate, H. Nishikawa, S. Umatani, Bulletin of the Ceramic Society of Japan, 54, 8, 573, 575,   2019 08 , 招待有り
  • P-72 Preparation and evaluation of potassium-containing hydroxyapatite sheet for dentin hyperesthesia treatment, Hatoko Y, Yamamoto E, Kato N, Nishikawa H, Yoshikawa K, Furuzono T, Yamamoto K, Hontsu S, The journal of the Japanese Society for Dental Materials and Devices, 34, 5, 416, 416,   2015 09 15
    Summary:In the therapy for hypersensitivity of tooth, it is known that potassium (K) compounds are often added in the toothpaste because it is believed that neurotransmission is blocked by potassium ions. Recently, we have been proposing the attachment therapy of a hydroxyapatite (HAp) sheet on dentin for hyperesthesia. It is thought that addition of K ions in HAp sheet is more effective for relieve pain of tooth hypersensitivity. In this study, we prepared K-HAp thin film and evaluated it. K-HAp sheet was prepared by using a process for preparing thin film. After that, we evaluated the interface between K-HAp sheet and dentin.
  • P-40 Evaluation on the effect of lap-strake perforated amorphous calcium phosphate sheets on the sealing of dentinal tubules, Ido Y, Isai A, Yamamoto E, Kato N, Nishikawa H, Yasuo K, Hashimoto Y, Yoshikawa K, Yamamoto K, Hontsu S, The journal of the Japanese Society for Dental Materials and Devices, 34, 2, 111, 111,   2015 03 25
    Summary:We propose a new method to shield dentinal tubules by direct attaching an amorphous calcium phosphate (ACP) sheet on the dentin as a treatment of the hyperaesthesia. In this study, we fabricated the perforated ACP sheet in order not only to easily remove liquid on the dentinal surface but also to promote the remineralization at the interface between the sheet and dentin. The ACP sheet was prepared by the pulsed laser deposition technique and the laser process using a metal mask. The interface structure between the ACP sheet and dentin was observed by a SEM. In addition, using Pashle's method, we evaluated the inhibition effect of lap-strake perforated ACP sheets attached to the dentin on its permeability.
  • P-15 Evaluation of the dentin permeability inhibition effect by lap-strake method of the amorphous calcium phosphate sheet, Isai A, Yamamoto E, Kato N, Nishikawa H, Yasuo K, Hashimoto Y, Yoshikawa K, Yamamoto K, Hontsu S, The journal of the Japanese Society for Dental Materials and Devices, 33, 5, 401, 401,   2014 09 20
    Summary:We have fabricated a flexible hydroxyapatite (HAp) sheet using pulsed laser deposition and a sheet isolation technique. We aim to form an artificial enamel layer on the dentin by an amorphous calcium phosphate (ACP) sheet with solubility higher than compared that of the crystallized sheet. In this study, using Pashle's method, we evaluated of the dentin permeability inhibition effect by double layer method of the ACP sheet on dentin as a cure for dental hypersensitivity. The dentin permeability inhibition rate of the dentinal tubule by double layer method of the ACP sheet was 89.17±7.24%. The ACP sheet was yielded results better than of dental resin cement.
  • P-16 Preparation and evaluation of ultra thin potassium-doped hydroxyapatite sheet, Hatoko Y, Yamamoto E, Kato N, Nishikawa H, Yoshikawa K, Furuzono T, Yamamoto K, Hontsu S, The journal of the Japanese Society for Dental Materials and Devices, 33, 5, 402, 402,   2014 09 20
    Summary:In toothpaste formulated for hypersensitivity, potassium compounds such as potassium nitrate and potassium bromide are often added because it is believed that neurotransmission is blocked by the function of potassium ions. Thus far, we have proposed attaching a hydroxyapatite sheet on dentin as a treatment for hyperesthesia. We think that it may be possible to block dental tubules and relieve pain by adding potassium to the sheet for sustained release. In this study, we prepared and evaluated a potassium-doped hydroxyapatite thin film, and applied the process to the preparation of a potassium-doped hydroxyapatite sheet.
  • A-18 Examination of dentine restoration using the Er:YAG laser ablation method (Part1), Hontsu S, Yamamoto E, Kato N, Nishikawa H, Hashimoto Y, Yoshikawa K, Yamamoto K, The journal of the Japanese Society for Dental Materials and Devices, 33, 2, 128, 128,   2014 03 25
    Summary:A calcium phosphate film was deposited on the dentine in the air by applying Er:YAG laser to the laser ablation (PLD) method to try the restoration of the dentine. α-tricalcium phosphate (α-TCP) was used as a target for the film preparation, and cattle enamel and human dentin were used as a substrate. X-ray diffraction (XRD) technique was used for crystallinity evaluation of the deposited layer, and scanning electron microscope (SEM) was used for the evaluation of the substrate-deposited layer interface.
  • Examination of enamel repairing method using ultrathin apatite sheet (Part2), HONTSU S, YOSHIKAWA K, ISAI A, YAMAMOTO E, KATO N, NISHIKAWA H, KUSUNOKI M, HASHIMOTO Y, YAMAMOTO K, The journal of the Japanese Society for Dental Materials and Devices, 32, 2, 125, 125,   2013 03 25
    Summary:We have successfully created a flexible hydroxyapatite (HAp) sheet of less than a few micrometers, and we have been trying to establish the all-HAp restoration technique for tooth enamel. In this study, we evaluated the re-calcification layer at the various sheets (amorphous HAp, HAp, amorphous HAp/amorphous calcium phosphate: ACP, HAp/ACP)-enamel interface by scanning electron microscope (SEM).
  • Formation of the artificial enamel on dentin using the ultrathin apatite sheet, HONTSU S, YOSHIKAWA K, ISAI A, YAMAMOTO E, KATO N, NISHIKAWA H, KUSUNOKI M, HASHIMOTO Y, YAMAMOTO K, The journal of the Japanese Society for Dental Materials and Devices, 31, 5, 445, 445,   2012 09 25
    Summary:We have fabricated a flexible hydroxyapatite (HAp) using a pulsed laser deposition (PLD) method and a film isolation technique. We adhered the HAp sheet to the dentine surface using a calcium phosphate aqueous in order to apply this sheet to hyperesthetic treatment. In the present study, the time dependence of the composition at the interfaces between the HAp/TCP sheet and the dentine was evaluated using X-ray diffraction measurement, and the adhesive strength between the HAp/TCP sheet and the dentine surface was evaluated by quasi-static tensile tests.
  • Examination of enamel repairing method using ultrathin apatite sheet (Part1), HONTSU S, YOSHIKAWA K, MATSUDA T, KATO N, NISHIKAWA H, KUSUNOKI M, HASHIMOTO Y, YAMAMOTO K, The journal of the Japanese Society for Dental Materials and Devices, 31, 2, 112, 112,   2012 03 25
    Summary:We have succeeded to fabricate flexible hydroxyapatite (HAp) sheet for adhering directly onto tooth and bone surfaces using a pulsed laser deposition method and a film isolation technique. We have investigated a method to regenerate the tooth enamel by just attaching the flexible HAp sheet onto the tooth surface with artificial saliva. In this paper, we report the result of adhering the HAp sheet to the enamel assisted by an TCP over-deposition and calcium phosphate aqueous solution in order to reduce the period required to regenerate the enamel.
  • Biosensor Applications of Apatite Thin Films Prepared by Pulsed Laser Deposition, S. Hontsu, M. Kusunoki, H. Nishikawa, Bulletin of the Ceramic Society of Japan, 46, 9, 745, 749,   2011 09 , 招待有り
  • Characteristics of a humidity sensor using a Na-doped hydroxyapatite thin film, S. Hontsu, M. Nakamori, H. Nishikawa, M. Kusunoki, Mem. Fac. B.O.S.T., Kinki Univ., 26, 87, 91,   2010 10 , Refereed
  • Micro-patterning technique for capillary blood vessels on Poly tetrafluoroethylene substrate, M. Kusunoki, T. Wada, H. Kanda, H. Togo, T. Hayami, Y. Hashimoto, H. Nishikawa, S. Hontsu, Mem. Fac. B.O.S.T., Kinki Univ., 25, 1, 6,   2010 03 , Refereed
  • ヒト間葉系幹細胞とハイドロキシアパタイトシートを組み合わせた新規骨再生誘導メンブレンの開発, HASHIMOTO NORIYA, YANAKA NAOKI, KUSUNOKI MASANOBU, NISHIKAWA HIROAKI, MOTOZU SHIGEKI, TAKEDA SHOJI, 日本再生歯科医学会誌, 7, 1, 82,   2009 12 30 , http://jglobal.jst.go.jp/detail.php?from=API&JGLOBAL_ID=201002251391497996
  • 極薄アパタイトシートの軟組織再生足場としての応用, ASANO HIROKI, TOGO HIDETAKA, HASHIMOTO YOSHIYA, KUSUNOKI MASANOBU, NISHIKAWA HIROAKI, HAYAMI TAKASHI, HONTSU SHIGEKI, 再生医療, 8, 260,   2009 02 05 , http://jglobal.jst.go.jp/detail.php?from=API&JGLOBAL_ID=200902204597949231
  • エキシマレーザーアブレーション法によるアパタイト被覆三次元チタン繊維細胞足場の開発, HASHIMOTO YOSHIYA, YOSHIKAWA YOSHIHIRO, ASANO HIROKI, KUSUNOKI MASANOBU, NISHIKAWA HIROAKI, HONTSU SHIGEKI, IKEO TAKASHI, AMETANI AKIHIRO, YOSHINO KAZUTAKA, KUBOKI YOSHINORI, 日本再生歯科医学会誌, 6, 1, 56,   2008 12 30 , http://jglobal.jst.go.jp/detail.php?from=API&JGLOBAL_ID=200902210575381940
  • Examination of Effect on Induce to Differentiated Neuronal Cell on Hydroxyapataite Coated Material, Takehara Toshiyuki, Hatanaka Ryota, Kusunoki Masanobu, Nishikawa Hiroaki, Hashimoto Noriya, Hontsu Shigeki, Hosoi Yoshihiko, Memoirs of the School of Biology-Oriented Science and Technology of Kinki University, 18, 18, 25, 29,   2006 09 30 , http://ci.nii.ac.jp/naid/110006183414
    Summary:Recently, advance to research for regenerative medicine and transplantation medicine of recover tissue. The transplant radical material that becomes an actual work stand of transplanted cells is researched and it is developed along with it. We study the influence on the differentiation induction of the embryonic stem cell (ESC) was examined by compatibility's with the biological tissue paying attention to the hydroxyapatite in which an immune rejection did not happen high either, and using the radical material that did this in the coating. Induce by differentiation from four processes; the initial differentiation structure (embryonic body) and the neural precursor cell were differentiating induced from the Cynomolgus monkey ESC is utilized as a tool for the clinical trial. We then were compared function cell differentiation/proliferation potency on each radical material. It became the one that adhering the neuronal cell was weak, and the cell proliferation potency is low on the titanium radical material though adhering the neuronal cell was high, and the formation of the axon externals structure was observed on the collagen coated and the hydroxyapatite coated radical material. It was thought that the hydroxyapatite was able to use as an excellent work stand in the differentiation proliferation of the neuronal cell, and was able to become a useful transplant radical material from these results.
  • レーザーアブレーション法を用いた生体アパタイト薄膜の細胞適合性評価(in vitro), HASHIMOTO YOSHINARI, HATANAKA RYOTA, KUSUNOKI MASANOBU, NISHIKAWA HIROAKI, HONTSU SHIGEKI, NAKAMURA MASAAKI, 歯科材料・器械, 24, 5, 353,   2005 09 05 , http://jglobal.jst.go.jp/detail.php?from=API&JGLOBAL_ID=200902243156221882
  • エキシマレーザーアブレージョン法を用いたハイドロキシアパタイトコートQCMセンサーの開発, HASHIMOTO YOSHINARI, KUSUNOKI MASANOBU, KAWASHIMA MASAMI, NISHIKAWA HIROAKI, HONTSU SHIGEKI, NAKAMURA MASAAKI, 歯科材料・器械, 23, 5, 328,   2004 09 10 , 10.14832/gsjsdmd.2004f.0.12.0, http://jglobal.jst.go.jp/detail.php?from=API&JGLOBAL_ID=200902295734754481
  • Fabrication and Investigation of High - Temperature Superconductor / Ferroelectric / Ferromagnetic Structures for Electrically and Magnetically Tunable Superconducting Microwave Devices, S. Hontsu, H. Nishikawa, Mem. School B.O.S.T., Kinki Univ., 10, 21, 28,   2002 07 , Refereed
  • Preparation of metal implants coated with high-adhesion hydroxyapatite thin film, Akai Masaya, Hontsu Shigeki, Nishikawa Hiroaki, Matsumoto Toshirou, Hosoi Yoshihiko, Ueda Yukio, 2002, 14, 13, 14,   2002 03 01 , http://ci.nii.ac.jp/naid/110002483680
  • Preparation of a Novel Implant of Lotus-Type Porous Stainless Steel Coated with Hydroxyapatite Thin Film, HONTSU Shigeki, AKAI Masaya, IKEDA Teruyuki, NISHIKAWA Hiroaki, HOSOI Yoshihiko, NAKAJIMA Hideo, 19, 5, 9, 13,   2001 10 10 , http://ci.nii.ac.jp/naid/50000971408

Awards & Honors

  •   2015 10 , The 14th International Union of Materials Research Societies-International Conference on Advanced Materials, Best Poster Award, Effect of concentration and pH of buffered phosphoric acid aqueous solution to surface nanostructures of Al2O3 (0001)
  •   2001 06 , The 8th International Superconductive Electronics Conference, Excellent Poster Award, Tuning Characteristics of Mechanically Tunable Superconducting Microwave Filter