Transactions of the Materials Research Society of Japan
Online ISSN : 2188-1650
Print ISSN : 1382-3469
ISSN-L : 1382-3469
39 巻 , 2 号
選択された号の論文の34件中1~34を表示しています
Review Paper
Regular Papers
  • Yoshinobu Hirose, Shintaro Ueno, Kouichi Nakashima, Satoshi Wada
    2014 年 39 巻 2 号 p. 105-108
    発行日: 2014/06/01
    公開日: 2014/08/16
    ジャーナル フリー
    To enhance the dielectric properties of barium titanate (BaTiO3, BT)/bismuth ferrite (BiFeO3, BF) nano-complex ceramics by a polarization rotation mechanism like a lead zirconate titanate, we tried to introduce structure-gradient region (SGR) in the BT/BF nano-complexes by constructing epitaxial interface between BT and BF layers. The green compacts consisting of TiO2 and BF nano-particles were hydrothermally converted into the BT/BF complexes compacts with various BT/BF molar ratios. It can be observed that the epitaxial BT layers were formed on the BF particles in the BT/BF complex with a molar ratio BT/BF=0.50 by the high-resolution transmission electron microscope. The dielectric properties of these nano-complexes tend to increase monotonically with the BT/BF molar ratio and the remarkable enhancement cannot be found despite of the formation of the BT/BF epitaxial interface. It can be considered that the displacement of Ti ions might be limited by the compressive stress on BT lattices due to the lattice mismatch at the epitaxial interface, and the dielectric properties did not enhance even if the SGR formed.
  • M. Muhibbullah, M. Golam Mowla Choudhury, Junie Jhon M. Vequizo
    2014 年 39 巻 2 号 p. 109-112
    発行日: 2014/06/01
    公開日: 2014/08/16
    ジャーナル フリー
      Copper oxide thin films of the drop chemical deposition technique were annealed in air ambient with the temperature range 100 to 400 °C, and annealing effect was investigated. The crystalline structure of the annealed samples has been converted from Cu2O to CuO phase, and the O/Cu ratio has been changed from 0.78 to 1. The surface morphology of the films was enough smooth after annealing. Photo-electrochemical measurement showed that the photosensitivity has been increased by the annealing.
  • Satoshi Wada, Kenta Yamashita, Ichiro Fujii, Kouichi Nakashima, Nobuhi ...
    2014 年 39 巻 2 号 p. 113-115
    発行日: 2014/06/01
    公開日: 2014/08/16
    ジャーナル フリー
    Barium titanate (BaTiO3, BT) - potassium niobate (KNbO3, KN) nano-structured ceramics with artificial morphotropic phase boundary (MPB) structure, were successfully prepared by solvothermal method at temperatures below 230 ˚C. Various characterizations suggested that the BT-KN nano-structured ceramics exhibited a porosity of around 30 % and heteroepitaxial interface between BT and KN. Their dielectric and piezoelectric properties were measured at room temperature, and the dielectric constant and apparent piezoelectric constant estimated from slope of strain and electric field curve was 370 and 136 pC/N, respectively.
  • Joanna Pawłat, Henryka Stryczewska, Kenji Ebihara, Fumiaki Mitsugi, Ta ...
    2014 年 39 巻 2 号 p. 117-120
    発行日: 2014/06/01
    公開日: 2014/08/16
    ジャーナル フリー
    In many locations, generation of electrical energy is restricted due to unfavorable logistic conditions. That limits introduction of new technologies, requiring electrical power including air, water and soil purification technologies. Small scale treatment installations supplied with electric energy from solar sources were proposed as a good example of zero-emission technology achieved with reasonable cost. Treatment process of agricultural samples, pathogens and pests based on ozone and advanced oxidation process was described.
  • Ryota Imura, Yuuki Kitanaka, Takeshi Oguchi, Yuji Noguchi, Masaru Miya ...
    2014 年 39 巻 2 号 p. 121-124
    発行日: 2014/06/01
    公開日: 2014/08/16
    ジャーナル フリー
    We have investigated the local structure and spontaneous polarization (Ps) of Ba1-xCaxTiO3 (BCT) by density functional theory (DFT) calculations. The DFT calculations based on a supercell approach show that Ca atoms are markedly displaced cooperatively with the adjacent Ti atoms along the Ps direction. It is suggested that the CaTiO3-like octahedral rotation is constructed in the BCT supercell around the Ca atoms, which is the origin of the smaller Ps of BCT.
  • Yusuke Sasaki, Michinari Kohri, Takashi Kojima, Tatsuo Taniguchi, Keik ...
    2014 年 39 巻 2 号 p. 125-128
    発行日: 2014/06/01
    公開日: 2014/08/16
    ジャーナル フリー
    We report the first synthesis of polymer nanoparticles employing the phase inversion temperature (PIT) method using a polymeric surfactant. Oil-in-water nanoemulsions were prepared by the PIT method using amphiphilic comb-like block polymer (polystyrene-b-poly[oligo(ethylene glycol) methyl ether methacrylate], PSt-b-POEGMA) as a polymeric surfactant, and subsequently St droplets were polymerized. PSt-b-POEGMA was synthesized by sequential atom transfer radical polymerization of St and OEGMA. The interfacial property of PSt-b-POEGMA in aqueous media was investigated by surface tension measurement and fluorescence probe technique. Monodisperse PSt nanoparticles with 50 nm in diameter were obtained by a free radical polymerization of St droplets initiated by the water-soluble initiator.
  • Seiya Amano, Kouichi Nakashima, Shintaro Ueno, Satoshi Wada
    2014 年 39 巻 2 号 p. 129-132
    発行日: 2014/06/01
    公開日: 2014/08/16
    ジャーナル フリー
    Barium titanate (BaTiO3) nanocubes were synthesized by solvothermal reaction. The synthesis was performed using barium hydroxide [Ba(OH)2], barium acetate [Ba(CH3COO)2], and titanium dioxide (TiO2) as starting materials, with Ba / Ti atomic ratio of 2.0 and Ti concentration of 0.04 mol / l. A mixture of ethanol, 2-methoxyethernol and water was added to the starting materials and this mixture was heated at 240°C for 18h in an autoclave. X-ray diffraction measurements confirmed the formation of BaTiO3 with a perovskite structure. The water served as an oxygen source for synthesis BaTiO3. Scanning electron microscopy (SEM) and transmission electron microscopy (TEM) observations revealed cube-shaped BaTiO3. In order to synthesize the small-scale BaTiO3 nanocubes, various reaction conditions such as the amount of water addition, kind of barium source, and amount of barium source were investigated. BaTiO3 nanocubes with sharp-edged corners were formed by increasing the proportion of Ba(CH3COO)2 used as a raw material for the barium source.
  • Takahiro Kikkawa, Yohei Kaneko, Atsuhiro Fujimori
    2014 年 39 巻 2 号 p. 133-136
    発行日: 2014/06/01
    公開日: 2014/08/16
    ジャーナル フリー
    Transition behavior from a monolayer on the water surface to a single particle layer of a ternary comb copolymer with highly hydrophobic carbazole units and both hydrogenated and fluorinated side-chains have been investigated by surface pressure−area (π−A) isotherm and atomic force microscopic (AFM) observation. Moreover, we fabricated a polymer nanosphere multilayered organization consisting of such polymer nanoparticles by the Langmuir–Blodgett (LB) technique, and estimated the particle arrangement by performing out-of-plane X-ray diffraction (XRD) analysis. This polymer monolayer is able to form the polymer nanosheet with amorphous layers. The multiparticle layered organization of polymer nanosphere is fabricated from the single particle layer by the LB technique. These layer structures have highly regular arrangement along the c-axis. Further, we investigated molecular arrangement inside of polymer particles by performing in-plane XRD analysis and fluorescence spectroscopy. This copolymer formed side-chain crystals inside the particles. Fluorocarbon chains had a short spacing of 5.0 Å for the two-dimensional side-chain lattice whereas hydrocarbon chains formed sub-cell at short spacing of 4.2 Å. In addition, aggregated structure of carbazole rings is formed by π-π interaction.
  • Haruumi Kamei, Shintaro Ueno, Kouichi Nakashima, Ichiro Fujii, Yoshihi ...
    2014 年 39 巻 2 号 p. 137-140
    発行日: 2014/06/01
    公開日: 2014/08/16
    ジャーナル フリー
    Mn-doped 0.45(Bi0.5K0.5)TiO3-0.1Bi(Mg0.5Ti0.5)O3-0.45BiFeO3 (BKT-BMT-BF) ceramics were prepared using BiFeO3 (BF) particles synthesized by a hydrothermal synthesis as a starting material to reduce defects originating from evaporation of Bi2O3. X-ray diffraction patterns revealed that the synthesized BF powder and the sintered BKT-BMT-BF ceramics consisted of a single perovskite phase. The grain size of the BKT-BMT-BF ceramics was lager than that prepared by a conventional solid state synthesis. The high-field piezoelectric properties were largely improved because of de-pinning of domain walls. The remanent polarization of 24.5 μC/cm2 and the apparent piezoelectric coefficient (d33*) of 268 pm/V were recorded.
  • Makoto Taguchi, Atsuhiro Fujimori
    2014 年 39 巻 2 号 p. 141-144
    発行日: 2014/06/01
    公開日: 2014/08/16
    ジャーナル フリー
    We investigated adsorption behavior of DNA molecules to ternary comb copolymers containing 2-vinyl-4, 6-diamino-1, 3, 5-triazine (VDAT) at air/water interface and their molecular arrangement. A newly ternary comb copolymers as adsorption template was synthesized by radical copolymerization of VDAT, octadecyl acrylate (OA), 2-(perfluorodecyl)ethyl methacrylate (FF10EMA). The IR spectrum and UV-vis spectrum of transferred LB multilayers indicates adsorption of DNA molecules by ternary copolymer templates. There were hydrogenated domains at 40–50 nm diameter scales in phase separated surface structure of Z-type monolayers. Furthermore, adsorbed DNA molecules showed segment domain at 100–200 nm scales. Fluorescence emission bands of adsorbed DNA to copolymer film showed red-shift and became sharper than the one of their so lution. It was caused by formation of aggregate of π-conjugated system in the DNA with uniform aggregation number. In the case of copolymer film containing N-vinyl carbazole (NVCz), small domain at 30-40 nm scales and DNA aggregate with various aggregation number were confirmed.
  • Kenta Goto, Takehiro Higuchi, Ohmi Fuchiwaki, Wataru Nakao
    2014 年 39 巻 2 号 p. 145-152
    発行日: 2014/06/01
    公開日: 2014/08/16
    ジャーナル フリー
    Capsule-type micro actuator driven by the volume change of hydrogen storage alloys (HSA-CMA) was proposed. HSA-CMA is specialized for the use in outer space, and its main application is anticipated to be mounted on the super multi-link space manipulator to capture space debris. It consists of a hollow sphere frame, a membrane of hydrogen storage alloy and a valve. The aim of this study is to examine the performance of HSA-CMA and to gain its optimal design. First, the eligible materials of the HSA membrane and the frame were discussed. Moreover, finite element analyses were carried out to determine the eligible topology parameters of HSA-CMA. Finally, the availability of HSA-CMA was evaluated by comparing its performance with that of other actuators. From the result of the analyses, the design map of HSA-CMA was developed and the available range of the design parameters was determined. The comparison result revealed HSA-CMA was superior to the piezoelectric actuator in the deformation and to the shape-memory alloy actuator in the generative force. It was concluded that HSA-CMA possesses high availability as an actuator used in space and its performance can be adjusted by varying the frame parameters according to the required performance.
  • Takashi Ohhashi, Takaaki Tsuruoka, Hidemi Nawafune, Kensuke Akamatsu
    2014 年 39 巻 2 号 p. 153-156
    発行日: 2014/06/01
    公開日: 2014/08/16
    ジャーナル フリー
    Facile synthesis of metal nanoparticles/metal-organic frameworks (MOFs) nanocomposite based on preferential self-assembly of frameworks on nanoparticle surface was accomplished by versatile layer-by-layer (LBL) approach. We report the successful growth of MIL-100(Fe) films on Ag nanoparticle surface. This approach involves the synthesis of polyvinylpyrrolidone (PVP)-functionalized Ag nanoparticles and stepwise growth of frameworks consisting of Fe3+ ions and benzene-1,3,5,-tricarboxylate (btc) on nanoparticles. Ag nanoparticles can be act as scaffolds for construction of MOF frameworks. The resulting Ag nanoparticle/MIL-100(Fe) core-shell nanostructures were characterized by transmission electron microscopy (TEM). Additionally, HKUST-1, consisting of Cu2+ ions and btc, was synthesized on Ag nanoparticle surface by the same LBL approach. The present approach can be utilized to fabricate various types of metal nanoparticles/MOF nanocomposites that exhibit the optoelectronic properties of the nanoparticles and the molecular sieving effect of the MOFs.
  • Hiroto Kohma, Kanako Uradokoro, Michinari Kohri, Tatsuo Taniguchi, Kei ...
    2014 年 39 巻 2 号 p. 157-160
    発行日: 2014/06/01
    公開日: 2014/08/16
    ジャーナル フリー
    Herein, we describe a general and versatile procedure to fabricate hierarchically structured coatings onto material surfaces using colorless polydopamine (PDA) thin layer and polymer brush layer. Firstly, atom transfer radical polymerization (ATRP) initiator-containing colorless PDA layer was coated onto various types of material surfaces. Then, surface-initiated ATRP was conducted to produce functional polymer brush layer. This methodology will be applied to a broad range of materials to modification of surface properties. Furthermore, one-step hierarchically structured coatings of materials surface were also investigated.
  • Xin Li, Chaoyang Li, Toshiyuki Kawaharamura, Dapeng Wang, Noriko Nitta ...
    2014 年 39 巻 2 号 p. 161-164
    発行日: 2014/06/01
    公開日: 2014/08/16
    ジャーナル フリー
    ZnO nanostructures with well-controlled growth on silicon substrate were fabricated in a reducing gas ambient following by a novel mist chemical vapor deposition (Mist CVD) treatment. The effects of Mist CVD post-treatment time on the crystal growth, structural properties were investigated. It was found that the morphology of ZnO nanostructures was significantly modified and regrown during Mist CVD post-treatment process. The crystallinity of ZnO nanostructures was remarkably changed after Mist CVD post-treatment due to the huge regrowth of nanostructures. The mechanism of the nanostructures growth in Mist CVD was investigated in detail.
  • Hiroyuki Sato, Nanae Yamashita, Tomokazu Iyoda, Motonori Komura
    2014 年 39 巻 2 号 p. 165-168
    発行日: 2014/06/01
    公開日: 2014/08/16
    ジャーナル フリー
    Amphiphilic liquid crystalline diblock copolymer, PEO-b-PMA(Az), forms highly ordered microphase separated film with perpendicular PEO cylinders on various substrate just by thermal annealing. Parallel oriented PEO cylinders film can be also obtained by surface covering method with poly(dimethylsiloxane) (PDMS) which inhibits the surface induced perpendicular cylinder formation. Herein, we present a simple procedure for alignment control of microdomains in micron-scale confined volume by high resolution inkjet printing (SIJ Technology) without patterned substrate. The PEO114-b-PMA(Az)43 lines with a several-micron width were prepared by the inkjet printing and subsequent PDMS top-coating and annealing. We found that PEO cylinders were oriented along the line just by the simple method. On the other hand, perpendicular PEO cylinders were obtained in the line without the top-coating. This method will afford several applications such as metallic nanowires, wire grid arrangement etc., because of the simple process without substrate pattering and desired shapes drawn by the printing system.
  • Kaoru MIZUNO, Kimihiko MORIKAWA, Hiroyuki OKAMOTO, Eiji HASHIMOTO
    2014 年 39 巻 2 号 p. 169-172
    発行日: 2014/06/01
    公開日: 2014/08/16
    ジャーナル フリー
      The vacancy generation process in ultrahigh-purity aluminum single crystals with a low dislocation density was investigated by synchrotron radiation topography using a white X-ray beam. Some straight lines were observed in the topographs taken after temperature rose to 300℃ from room temperature, and they were confirmed to be rows of successive small interstitial-type dislocation loops grown as vacancy sources. It was concluded that the thermal generation mechanism of vacancies in ultrahigh-purity aluminum single crystals with a low dislocation density consists of the following two steps. First, small interstitial loops are heterogeneously formed in the crystal lattice; second, these convert to lengthened loops with the development of screw components and finally grow into rows of dislocation loops emitting vacancies into the lattice. However, contribution of new vacancy generation mechanism, growth of row of interstitial type dislocation loop for thermal equilibrium vacancy concentration is less than several percent. Therefore, major vacancy source is small vacancy cluster or vacancy type dislocation loops grown after slow cooling during crystal growth.
  • Hideto Kawashima, Shintaro Ueno, Kouichi Nakashima, Satoshi Wada
    2014 年 39 巻 2 号 p. 173-176
    発行日: 2014/06/01
    公開日: 2014/08/16
    ジャーナル フリー
    The KN/BT nanocomplex ceramics with the necking structure were prepared by the solvothermal method to improve dielectric properties and piezoelectric response of barium titanate (BaTiO3, BT)-based ceramics by introducing a three-dimensionally connected structure-gradient region (3D-connected SGR). We attempted to form epitaxial potassium niobate (KNbO3, KN) layers on the sintered BT particle compacts with the necking structure by the solvothermal method at the various temperatures. The presence of the 3D-connected SGR in the KN/BT nanocomplex ceramics is suggested by the XRD measurement and the maximal dielectric constant of 1640 (at 1 MHz) and the maximal apparent piezoelectric constant, d33*, of 430 pm/V (at 0.1 Hz) were recorded for the KN/BT nanocomplex ceramics prepared at 200 °C. The introduction of the 3D-connected SGR is possible to contribute to the enhancement in the dielectric properties and the piezoelectric responses.
  • Tohru Nakamura
    2014 年 39 巻 2 号 p. 177-180
    発行日: 2014/06/01
    公開日: 2014/08/16
    ジャーナル フリー
      Adsorption states of tellurobezoates having telluro-carbonyl group were studied on Au(111) by X-ray photoelectron spectroscopy (XPS) and atomic force microscopy (AFM) measurements. XPS spectra show that the molecules form organic tellurium-oxide layers. Acids such as trifluoroacetic and sulfuric acid accelerate an accumulation of tellurium-oxide species originating from Te-phenyl tellurobenzoate molecules to cover the surfaces with thick layers, which indicate relatively high resistances. Conductive AFM revealed the high resistance of accumulated tellurium-oxide films and the disruptive strength against dielectric breakdown.
  • Shintaro Ueno, Yasunao Sakamoto, Kouich Nakashima, Satoshi Wada
    2014 年 39 巻 2 号 p. 181-184
    発行日: 2014/06/01
    公開日: 2014/08/16
    ジャーナル フリー
    To develop the high-volume energy storage device based on ceramic capacitors, we attempted that Ti metal particles working as internal electrodes were distributed in barium titanate (BT) layers. We compared two kinds of the metal particles; uncoated Ti metal particles and Ti-BT core-shell particles (Ti metal particles with thin BT coating layers). The green compacts consisting of the metal particles, titanium oxide precursor particles, and barium titanate fillers were successfully converted into the Ti/BT composite compacts by the hydrothermal method without heating procedure. The effective dielectric constant of these composites tends to increase with a metal content, and then drastically increases up to over 103 near the percolation threshold (insulator-metal transition point). These dielectric constant behaviors can be explained by the percolation theory. By using the core-shell particles, the percolation threshold increases from 0.609 to 0.734, suggesting that the BT shell layers were effective to suppress the current leakage.
  • Sho Sakata, Yuuki Inoue, Kazuhiko Ishihara
    2014 年 39 巻 2 号 p. 185-188
    発行日: 2014/06/01
    公開日: 2014/08/16
    ジャーナル フリー
    Protein adsorption behavior was examined from viewpoint of molecular interaction force generating on material surfaces. To achieve this, the methodology to evaluate the nano-scale molecular interaction forces on the well-defined surfaces by the force-versus-distance curve measurements using atomic force microscopy (AFM) was established. Zwitterionic, cationic, anionic, and hydrophobic polymer brush surfaces were prepared as model surfaces to analyze the interaction forces operating on the surfaces. The amount of proteins adsorbed on the polymer brush surfaces was quantified by surface plasmon resonance measurement. The molecular interaction forces operating on the polymer brush surfaces were evaluated using the AFM probes modified with functional groups. On the zwitterionic polymer brush surface, molecular interaction forces were not observed, and amount of protein adsorption was little. On the other hand, cationic, anionic, or hydrophobic polymer brush surface exhibited strong molecular interaction forces, and large amount of proteins adsorbed on these surfaces. These results indicated that the preparation of material surfaces, which avoid the molecular interactions, is significant for suppression of protein adsorption.
  • Youichi Soutome, Takuma Kanehira, Shuntaro Arai, Munehiro Kubota, Kei- ...
    2014 年 39 巻 2 号 p. 189-192
    発行日: 2014/06/01
    公開日: 2014/08/16
    ジャーナル フリー
    Nanocomposite of poly[tetrafluoroethylene-co-perfluoroethylvinylethel] (abbrev. PFA) / long-chain quaternary phosphonium modified clay (C16-P-MMT) have been prepared by melt-compounding process using fluorinated crystalline polymer and C16-P-MMT. The structures of polymer and dispersed C16-P-MMT in matrix were investigated by using Wide angle X-ray diffraction (WAXD). The crystallization temperature was determined using a Differential Scanning Calorimetry (DSC). From WAXD profiles, it was found that C16-P-MMT were almost uniformly dispersed in matrix, while the characteristic diffraction profiles of C16-P-MMT are not shown in WAXD profiles of nanocomposite. Further, the intensity of most characteristic diffraction profile of PFA is increased for the composite sample as compared with that of the neat PFA. And also the crystallite size of the PFA is increased. These results suggest that degree of crystallinity are increased for the composite sample as compared with that of the neat PFA. In addition, a crystalline peak these nanocomposites showed in DSC thermograms (first cooling) was shifted to higher temperature side than of neat PFA. It is suggested that the origin of this thermal behavior corresponds to occurrence the nucleator effect of C16-P-MMT to the matrix PFA. Further, transparent PFA / C16-P-MMT nanocomposite film was constructed by drawn.
  • Kouichi Nakashima, Shintaro Ueno, Satoshi Wada
    2014 年 39 巻 2 号 p. 193-197
    発行日: 2014/06/01
    公開日: 2014/08/16
    ジャーナル フリー
    Potassium niobate (KNbO3) is a perovskite oxide functional material that has been attracting attention as dielectric materials. The present work describes the fabrication of the KNbO3 nanocubes by wet chemical reaction. The preparation and characterization of the KNbO3 nanocubes were investigated. KNbO3 was prepared using a solvothermal method. 40 mL organic solvent was used such as methanol, ethanol, 2-(2-methoxyethoxy)ethanol, 2-(2-ethoxyethoxy)ethanol, and 2-(2-n-butoxyethoxy)ethanol while niobium oxide (Nb2O5) and potassium hydroxide (KOH) were used as raw materials. The reaction was performed at 230 - 250℃ for 18 h. The characterization was carried out using X-ray diffraction (XRD) and scanning electron microscopy (SEM). When solvothermal syntheses were performed with various organic solvents, KNbO3 was formed from the XRD measurement and KNbO3 nanocubes were obtained from SEM observations. Particularly, KNbO3 nanocubes were the smallest size when the methanol solvent was used in this study.
  • Eigo Kobayashi, Shintaro Ueno, Kouichi Nakashima, Nobuhiro Kumada, Toh ...
    2014 年 39 巻 2 号 p. 199-202
    発行日: 2014/06/01
    公開日: 2014/08/16
    ジャーナル フリー
    (111)-oriented Mn and Nb-doped barium titanate (BaTiO3, BT) ceramics with fine grains were fabricated with an electrophoretic deposition (EPD) method in a high magnetic field and a topotactic phase transition. Initially, accumulations of (0001)-oriented hexagonal Ba(Ti0.95Mn0.05)O3 particles added with 2.5 mol%-Nb2O5 powder were prepared by the EPD method in the high magnetic field of 12 T. Then, the (111)-oriented, Mn and Nb-doped pseudo-cubic BT ceramics with fine grains of ~0.4 µm in diameter were obtained via the topotactic phase transition, with the degree of the (111) orientation being as high as 79 %. The piezoelectric properties of the oriented ceramics were also studied.
  • Takashi Nishida, Ryo Onodera
    2014 年 39 巻 2 号 p. 203-206
    発行日: 2014/06/01
    公開日: 2014/08/16
    ジャーナル フリー
    Tunable microwave devices have been widely investigated because next generation information communication equipment will require accommodation of several communication protocols and frequencies. Barium strontium titanate (Ba,Sr)TiO3 (BST) thin films are expected to be applied in such devices because of their nonlinear dielectric characteristics in microwave frequencies. BST thin films have been deposited on various substrate materials, such as sapphire, MgO and glass, and the characteristics of thin film capacitors fabricated using BST have been investigated. The evaluation of electrical properties on in-plane type BST capacitors with inter-digital electrodes (IDE) and coplanar waveguide (CPW) type devices is important; however, there have been few detailed analyses or reports thus far. We prepared IDE and CPW electrodes of various sizes on BST films on sapphire. The size and voltage dependence of the capacitance and filter characteristics was determined. In this work, BST epitaxial films were deposited on sapphire substrates by rf magnetron sputtering. In order to obtain higher tunability, IDE electrodes with fine patterns below 1 μm were fabricated by electron beam (EB) lithography. The bias voltage dependence of the capacitance of the IDEs was measured. The tunability was found to increase with decreasing electrode spacing. The maximum tunability of 13.6 % was obtained at 100 nm IDE. CPW resonators of 6 mm length and 0.14 mm width were also prepared on BST (BST CPW) by EB lithography. The resonance frequency of 6.9 GHz of the BST CPW was calculated by a microwave simulator, which agreed with the measurement result of 7.47 GHz. A frequency shift of 1.1 % with bias voltage (50 V) was measured, revealing that a CPW type microwave tunable filter was successfully obtained on the BST/sapphire structure.
  • Kazuya Shishito, Hajime Fukuda, Hideyuki Tagaya
    2014 年 39 巻 2 号 p. 207-210
    発行日: 2014/06/01
    公開日: 2014/08/16
    ジャーナル フリー
    Layered organic – inorganic nano hybrids were prepared by the self-assembly reaction of magnesium hydroxide and calcium hydroxide with L-phenylalanine. Layered structures were confirmed by TEM images directly. Interlayer spacing of the layered hybrid was 1.61 nm in the case of magnesium hydroxide and 1.65 nm in the case of calcium hydroxide. It indicates the presence of bi layer structure of L-phenylalanine between the layers. Self-assembly reaction was also confirmed in the reaction of L-phenylalanine with the mixture of magnesium and calcium hydroxides. Interlayer spacing increased with an increase in the amount of calcium hydroxide from 1.61 nm to 1.65 nm.
  • Ohmi Fuchiwaki, Manabu Yatsurugi, Takashi Sato
    2014 年 39 巻 2 号 p. 211-215
    発行日: 2014/06/01
    公開日: 2014/08/16
    ジャーナル フリー
    In this paper, we describe the basic performance of a miniature omnidirectional inchworm robot driven by six piezoelectric actuators and a pair of Y-shaped electromagnets using the inchworm principle of motion. In several experiments, we determined the repeatability of positioning via translational motion in 8 directions within a several centimeter range. We also describe the theory of the feedforward plus feedback control method within 1 step motion and its experimental results with 50 nm measuring resolution. These results may be applied in the development of multi-functional precise processing in the biomedical and nanoscience fields.
  • Jun’ya Tsutsumi, Toshikazu Yamada, Tatsuo Hasegawa
    2014 年 39 巻 2 号 p. 217-219
    発行日: 2014/06/01
    公開日: 2014/08/16
    ジャーナル フリー
    The origin of relaxed exciton formation and its effect on photocarrier generation were examined for a typical donor-acceptor (DA)-type polymer, poly{[9-(1-octylnonyl)-9H-carbazole-2,7-diyl]-2,5-thiophenediyl-2,1,3-benzothiadiazole-4,7-diyl-2,5-thiophenediyl} (PCDTBT), with a focus on the two unique photoabsorption bands that originate from charge-transfer (CT) and main-chain (MC) excitations, respectively. The results of electroabsorption measurements showed that the CT excitation spatially localizes more than the MC excitation, which plays a crucial role for the relaxed exciton formation. The photocarrier generation characteristics are discussed in terms of the spatial localization of the CT and MC excitations.
  • H. Inoue, M. Kato, I.J. Ohsugi
    2014 年 39 巻 2 号 p. 221-223
    発行日: 2014/06/01
    公開日: 2014/08/16
    ジャーナル フリー
    Magnesium silicide has been investigated since for over 30 years because of its superior thermoelectric characteristics and lightweight. Its practical use, however, has not been realized yet, since the main component Mg is hard to be handled. Magnesium silicide bulk is almost produced by sintering with pressing such as spark plasma sintering or hot-pressing. Sintering with pressing is unsuitable for mass-production because of the small product size and the high production cost. In this work, a modified process of usual pressure-less sintering, which is useful for mass-production, was employed to produce sintered bodies of magnesium silicide. Pressing in an inert gas atmosphere successfully yielded pressure-less sintered bodies with a sufficiently small unevenness of the characteristics. The sintered bodies obtained were confirmed to have the superior thermoelectric properties, namely a Seebeck coefficient of -162 μV/K, a resistivity of 0.15 mΩm and 2.54 W/mK for n-type; +209 μV/K, 0.017 mΩm and 2.73 W/mK for p-type.
  • Tomoka Nakazumi, Daigo Murai, Kazuhito Tsukagoshi, Manabu Kiguchi
    2014 年 39 巻 2 号 p. 225-229
    発行日: 2014/06/01
    公開日: 2014/08/16
    ジャーナル フリー
    We have developed a measurement system for investigating metal atomic contacts under defined environmental conditions (0.1 Pa–105 Pa, 4 K–300 K). Using this newly developed system, the conductance behavior and lifetime of Au atomic contacts were investigated in vacuum and in an oxygen atmosphere (~105 Pa) at room temperature. The conductance curves and conductance histograms of the Au contacts in vacuum agreed with those measured in the oxygen atmosphere, indicating a weak interaction between oxygen and Au atomic contact. While the conductance behavior was not affected by the presence of oxygen, the lifetime of the Au atomic contact was slightly increased by the presence of oxygen.
  • Takuma Kanehira, Youichi Soutome, Nanami Honda, Shuichi Akasaka, Atsuh ...
    2014 年 39 巻 2 号 p. 231-234
    発行日: 2014/06/01
    公開日: 2014/08/16
    ジャーナル フリー
    The poly[vinylidenefluoride-co-(tetrafluoroethylene)] (P(VDF-TeFE)) / organo-modified nanodiamond (organo-ND) composite were prepared by the melt-compounding process using fluorinated crystalline polymer and organo-ND. The structure of the polymer and the structures of dispersed organo-ND particles in the polymer matrix were investigated by using an atomic force microscope (AFM). The crystallization temperature was determined using a Differential Scanning Calorimetry (DSC). From the AFM image, the organo-ND disperses in the polymer matrix. These results suggest that organo-ND with hydrocarbon chain can be dispersed in a fluorinated copolymer. From DSC thermograms (first cooling), the crystallization peak of DSC thermograms of the composite appeared at slightly higher temperature than that of the neat P(VDF-TeFE). These results suggest that the polymer crystallizes epitaxially from organo-ND surface.
  • Toshimasa Suzuka, Kazuhito Ogihara, Matsutake Higa
    2014 年 39 巻 2 号 p. 235-238
    発行日: 2014/06/01
    公開日: 2014/08/16
    ジャーナル フリー
      In this study, a polymer-supported terpyridine–palladium complex was prepared and found to promote the transfer reduction of aryl chlorides with potassium formate in water. Thus, terpyridine ligand was prepared from 4-methoxycarbonylbenzaldehyde, 2-acetylpyridine, NH4OAc according to the reported procedures. Immobilization of terpyridine ligand onto a PS-PEG resin took place and the complexation of PS-PEG-terpyridine ligand with Pd(II) underwent to give PS-PEG-terpyridine-Pd(II) complex. The polymeric catalysts showed high catalytic activity and high reusability for the transfer reduction in water.
  • Shigeki Mukoyama, Hitoshi Ohnuki, Hideaki Endo, Daiju Tsuya, Mitsuru I ...
    2014 年 39 巻 2 号 p. 239-242
    発行日: 2014/06/01
    公開日: 2014/08/16
    ジャーナル フリー
    Simple and robust properties are the important aspects for biosensing chip. We have fabricated Pt and Au interdigitated array electrodes (Pt-Au IDEs) for amperometric biosensor. A spontaneous electrical current generation was observed depending on H2O2 concentration. The glucose oxidase (GOx) immobilized Pt-Au IDEs exhibited a glucose sensor action in which H2O2 produced by the enzymatic reaction of GOx was detected through Pt-Au IDEs. The phenomenon demonstrated that Pt-Au IDEs can provide a simple amperometric biosensor without an external potential source nor a reference electrode.
  • ―Development of Heat-resistant Powder with High Coverage, and Organized Film with High Regularity―
    Takahiro Kikkawa, Shuntaro Arai, Masamichi Hashimoto, Atsuhiro Fujimor ...
    2014 年 39 巻 2 号 p. 243-246
    発行日: 2014/06/01
    公開日: 2014/08/16
    ジャーナル フリー
    We have attempted to fabricate heat-resistant ultrathin organized molecular films of several organo-modified montmorillonite (MMT) by applying the Langmuir-Blodgett (LB) method. Thermal degradation temperature of long-chain-phosphonium-modified MMT (C16-P-MMT) in bulk has been found to exceed 300 °C. The out-of-plane X-ray diffraction patterns observed for multilayer of C16-P-MMT with varying the sample temperature have indicated annealing effects on the film regularity, i.e., remarkable improvement of the long range order at the initial stage (up to 100 °C) and, in contrast, at the subsequent stage gradual collapse of the layered structure.
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