Transactions of the Materials Research Society of Japan
Online ISSN : 2188-1650
Print ISSN : 1382-3469
ISSN-L : 1382-3469
35 巻 , 3 号
選択された号の論文の59件中1~50を表示しています
Review Papers
  • Toshiyuki Mori, Ding Rong Ou, Fei Ye, Jin Zou, John Drennan, Alstair N ...
    2010 年 35 巻 3 号 p. 431-441
    発行日: 2010/09/01
    公開日: 2014/05/13
    ジャーナル フリー
      Doped ceria (CeO2) compounds are fluorite related oxides which show oxide ionic conductivity higher than yttria-stabilized zirconia in oxidizing atmosphere. As a consequence of this, considerable interest has been shown in application of these materials for 'intermediate temperature (300- 500℃)' operation of solid oxide fuel cells (SOFCs). In this review paper, our experimental data was re-introduced to propose a new design paradigm for development of high quality doped CeO2 electrolytes. Based on our experimental data, our original idea a control of nano-inhomogeity of doped CeO2 electrolytes was proposed. In our work, the nano-sized powders and dense sintered bodies of M doped CeO2 (M: Sm, Gd, Y, Yb, Dy, Ho, Tb and La) specimens were fabricated using ammonium carbonate co-precipitation method, conventional sintering method and pulsed electric current sintering method. Also nano-structural features of those specimens were carefully observed for conclusion of relationship between electrolytic properties and microstructure in doped CeO2. It is essential that the electrolytic properties of doped CeO2 reflect in changes of microstructure even down to the atomic scale. Accordingly, a combined approach of ultimate analysis, simulation and processing route design is required to develop the superior quality doped CeO2 electrolytes for the intermediate temperature operation of SOFCs.
  • Naoto Shirahata
    2010 年 35 巻 3 号 p. 443-448
    発行日: 2010/09/01
    公開日: 2014/05/13
    ジャーナル フリー
      This review paper describes some of our recent topics on surface functionalization of IV semiconductors. Well-designed surfaces of the semiconductors create exciting opportunities for technological applications. To meet such exciting functionality, we use a monolayer system in which the reactive monolayer attaches to the semiconductor surface via covalent linkage. Most importantly, this molecular system enables chemists to manipulate the non-oxidized surfaces of the semiconductors even under ambient conditions. A variety of organic approaches is available to modify the surface chemical property in a lab environment without surrounding environmental control using glove box. The covalent attachment of organic monolayers leads to the appearance of unique property. For example, (i) The surface organic passivation leads to the highly efficient luminescence from silicon nanoparticles. Interestingly, the monomolecular density can controls the optical transition process of photoexcited careers in the nanostructured silicon. (ii) A multifunctional microarray, in which different types of self-assembled monolayers (SAMs) are respectively positioned on predefined surface sites, allows the parallel detection of different bimolecular interactions under the same buffer condition. (iii) The successful formation of reactive moieties on the IV semiconductors has provided unique chemical template for subsequent biomolecular attachment. The industrial use of IV semiconductors provides the unsurpassed compatibility with microelectronics. Furthermore, these semiconductors with a high chemical affinity for carbon, oxygen, and nitrogen have a potential to produce a variety of its organic derivatives hybridized at the molecular level.
  • Kazuhiro Hara, Satoru Yoshioka, Tetsuaki Nishida
    2010 年 35 巻 3 号 p. 449-454
    発行日: 2010/09/01
    公開日: 2014/05/13
    ジャーナル フリー
      For alleviating both of the environmental and resource-depletion problems related to heavy metals, the authors examined the heavy-metal adsorption and desorption functionalities of some hydrogels. It was found that the functional hydrogels can capture the heavy metals more efficiently than other adsorbents, and besides, some of them can desorb the adsorbed heavy metal with the efficiency of ~100%. From these experimental results, the authors have proposed a new heavy-metal recycling system in which the hydrogel adsorbent is also recycled repeatedly.
  • John G. Fisher, Suk-Joong L. Kang
    2010 年 35 巻 3 号 p. 455-460
    発行日: 2010/09/01
    公開日: 2014/05/13
    ジャーナル フリー
      Control of microstructure during processing is necessary to produce materials with optimum properties. Grain growth behaviour in both two-phase (solid/liquid) and single phase materials is strongly dependant on interface structure, either rough (atomically disordered) or faceted (atomically ordered). Materials with disordered interfaces show normal grain growth behaviour, whereas materials with ordered interfaces can show different types of non-normal grain growth, which are system and timedependant: pseudo-normal, abnormal, stagnant and delayed abnormal. Examples of the different types of grain growth are given from ceramic and metallic systems, and general principles of microstructure evolution with respect to interface structure are presented.
  • Hiroshi Yamamoto, Nobuyuki Iwata
    2010 年 35 巻 3 号 p. 461-466
    発行日: 2010/09/01
    公開日: 2014/05/13
    ジャーナル フリー
      This paper is the review for the authors' works on Free Electron Laser (FEL) irradiation effects aiming at syntheses of 3-dimensional C60 polymers. The used pristine was 99.5% C60 powder or the mixture with iodine, and also C60 precipitates prepared by a liquid-liquid interfacial precipitation (LLIP) method. The pristine was set in the vacuum and was compressed in the anvil with the pressure of 600 MPa~7 GPa. The third harmonics (@400-500 nm) FEL was irradiated with a macro-pulse (@20 μs) containing very short micro-pulses (@200 fs). The Raman Ag(2) peak of C60 molecules in the vicinity of 1469 cm-1 becomes broad and shifts to the lower energy side as proceeding of polymerization. Under higher pressure the larger red-shift and the increment of the half width of the Raman peak were observed. The irradiated mixture with iodine revealed the more distinctive red-shift, above 10 cm-1. Also the large peak red-shift ca. 10cm-1 was observed in the LLIP specimen probably because of highly packing of C60 molecules. The obtained results suggested that the C60 molecular accession and/or the photon-assisted hole-doping from iodine were decisively effective to promote photo-polymerization.
  • Robert F. Davis
    2010 年 35 巻 3 号 p. 467-471
    発行日: 2010/09/01
    公開日: 2014/05/13
    ジャーナル フリー
    Fuel-based and incandescent lamps convert ≤ 5% of the energy they consume into visible light; the remaining energy is given off as heat. The conversion efficiency of fluorescent lamps is approximately 20%. These very common sources of light convert the earth's energy sources mostly into waste heat and greenhouse gases. The increasingly precious energy resources and the increasing evidence of pollution-driven climate change demand that we reduce the energy and environmental costs of these forms of artificial lighting both by improving these sources and the employment of new forms of lighting. Light-emitting diodes (LEDs) convert electricity into light using semiconductor materials and, at present, represent the energy efficient technology of the future. Currently, LEDs are primarily used for interior and display lighting, as the efficiency of the diodes “droops” rapidly with an increase in the injected current that is necessary to achieve high-brightness. Exterior solid-state lighting within cities is being tested; however, much research, engineering and technological development remain necessary to achieve increased efficiency, low heat generation and the color temperatures and color rendering that are acceptable to human visual perception.
  • Shigeyuki Somiya, Sridhar Komarneni, Rustum Roy
    2010 年 35 巻 3 号 p. 473-483
    発行日: 2010/09/01
    公開日: 2014/05/13
    ジャーナル フリー
    One of the most important factors for advanced ceramics preparation is nature of the powders. There are many methods to prepare powders for ceramics, namely, mechanical, thermal decomposition, precipitation, hydrolysis, hydrothermal, melt and quenching, etc. This is a review of powder preparation for advanced ceramics. Characteristics of these methods are described. And also ideal powder for advanced ceramics is described.
  • Yasuro Ikuma, Srinivasan Anandan, Koichi Niwa
    2010 年 35 巻 3 号 p. 485-489
    発行日: 2010/09/01
    公開日: 2014/05/13
    ジャーナル フリー
    The results of x-ray diffraction, the size of lattice parameter, and the values of oxygen diffusion coefficient in YO1.5-CeO2, GdO1.5-CeO2, and NdO1.5-CeO2 systems were reviewed. In YO1.5-CeO2 system, the lattice parameter decreases as the concentration of YO1.5 increases. In GdO1.5-CeO2 system, the lattice parameter does not change very much. And in NdO1.5-CeO2 system, it increases as the concentration of NdO1.5 increases. When the oxygen diffusion coefficient was plotted as a function of lattice parameter, there was no correlation between them. However, when the oxygen diffusion coefficient was plotted as a function of the concentration of trivalent cation additives, there was very good correlation between them. Consequently, the diffusion coefficient does not depend on the size of crystal lattice in ceria solid solutions, but it depends on the concentration of trivalent cation additives.
Regular Papers
  • Shigeru Tanaka, Hironori Maehara, Mikiya Matsuda, Shigeru Itoh
    2010 年 35 巻 3 号 p. 491-494
    発行日: 2010/09/01
    公開日: 2014/05/13
    ジャーナル フリー
    New technique of rice powdering was developed by using shock wave. Current charged in a condenser is discharged large.current instantaneously at between electrodes where is placed in water. Under water shock wave is generated from between the electrodes. Rice and titanium ball are put into polycarbonate bottle by half of the bottle, and the rice is separated from water by the bottle. The bottle contained the rice is loaded by under.water shock wave, the rice is accelerated to high velocity and collided with each other. The shock loaded process does not generate heat during powdering, because the process is finished momentary. Heat is generated in conventional process of rice powdering, and the heat lose flavor of rice. Potential flavor of rice is maintained and bactericide effect is expected by this technique. Recovered rice powder was evaluated by grain distribution.
  • Miwa Saito, Toshio Takayama, Hiroshi Yamamura
    2010 年 35 巻 3 号 p. 495-498
    発行日: 2010/09/01
    公開日: 2014/05/13
    ジャーナル フリー
    In order to obtain high ionic conducting materials based on perovskite structure for the electrolyte of Solid Oxide Fuel Cells (SOFCs), Ba2(Zn2/3B'1/3)2O5 (B'= Nb and Ta) and Ba2(Zn3/4W1/4)2O5 systems were synthesized by solid state reaction. Powder X-ray diffraction analysis revealed that the samples with B' = Nb and Ta in Ba2(Zn2/3B'1/3)2O5 had a cubic and a hexagonal perovskite-type structures, respectively, and that Ba2(Zn3/4W1/4)2O5 had a cubic NaCl structure. These materials exhibited the uptake of large amount of H2O and the appearance of high proton conductivity.
  • Hiroshi Kawakami, Mayuka Anzai, Mina Sugimoto, Toshio Takayama, Hirosh ...
    2010 年 35 巻 3 号 p. 499-502
    発行日: 2010/09/01
    公開日: 2014/05/13
    ジャーナル フリー
      The orthorhombic perovskite-type oxides having A-site vacancy, Ca1-xLa2x/3x/3MnO3, were synthesized by a standard ceramic technique. The thermoelectric properties such as Seebeck coefficient (S), thermal conductivity (κ) and electrical conductivity (σ) were investigated as functions of temperature and composition. The effects of insertion of A-site vacancy to the perovskite-type structure on the thermoelectric properties were investigated.
  • Mayuka Anzai, Hiroshi Kawakami, Toshio Takayama, Hiroshi Yamamura
    2010 年 35 巻 3 号 p. 503-506
    発行日: 2010/09/01
    公開日: 2014/05/13
    ジャーナル フリー
      Thermoelectric properties of Sr-doped LaCoO3 system such as La1-xSrxCoO3 and La0.95-xSrx0.05CoO3 (□: A-site vacancy) were investigated. The effects of A-site vacancy on electrical conductivity, Seebeck coefficient, and thermal conductivity were discussed. It was found that the thermoelectric properties of La0.95-xSrx0.05CoO3 containing the A-site vacancy showed the higher values than those of La1-xSrxCoO3 at 873K.
  • Shigeharu Ito, Miwa Saito, Toshio Takayama, Hiroshi Yamamura
    2010 年 35 巻 3 号 p. 507-509
    発行日: 2010/09/01
    公開日: 2014/05/13
    ジャーナル フリー
      Oxide ion conductor has been desired for application to solid oxide fule cells (SOFCs), which can be operated at temperatures below 873K. In order to obtain a new oxide-ion conductor, di-(M) and tetra-(M') valent cations were co-doped to the In-site of Ba2In2O5 which is known to be high oxide-ion conductor at high temperature above 1203K. The A2(M,M')2O5 systems (A=Ba, Sr; M=Zn, ; M'=Zr, Ce, Ti. Hf, Sn) having a brownmillerite-type compositions were prepared by solid state reaction. X-ray diffraction analyses confirmed that only the combinations of (Ba-Zn-Zr), (Ba-Zr-Ce), (Ba-Zn-Hf), (Sr-Zn-Zr), (Sr-Zn-Ti) and (Sr-Zn-Hf) for the A-M-M' in the present systems showed single phases of cubic or orthorhombic perovskite-type structures at room temperature. It was found that the electrical comductivities of the new phases increased with increasing the unit cell free volume.
  • Yuichiro Kawahara, Takanori Sasaki, Yoshimine Tanabu, Kiyoshi Kawamoto ...
    2010 年 35 巻 3 号 p. 511-514
    発行日: 2010/09/01
    公開日: 2014/05/13
    ジャーナル フリー
    The temperature rise of solar cells is one of the factors to decrease conversion efficiency of photovoltaic. We have developed a wavelength selective transmission thin film to prevent from temperature rise by cut-off near infrared rays which cause temperature rise. However, these optical thin films were designed with considering only normal incidence of sunlight. The change of incident angle of solar light shifts cut-off band to the short wavelength, which is required to power generation. Furthermore, these films had ripples in transmittance of visible light, and it caused little decrease of conversion efficiency. Therefore, in this research, we designed and prepared new wavelength selective transmission thin film with considering incident angular dependence of transmittance and the prevention of visible area ripples. Characteristics of former optical film and newly designed one were compared. Both of films were able to prevent from temperature rise of the solar cells than ordinary cover glass. However, former thin film could not prevent from decrease of conversion efficiency. On the other hand, conversion efficiency with newly designed thin film was higher than ordinary cover glass. According to these results, it was clarified that the shift of cut-off band by the incident angle change and ripples of visible band transmittance are important factor of the decrease of conversion efficiency, and prevention of them is important for actual use of photovoltaic.
  • Konomi Sato, Yusuke Kataoka, Wasuke Mori
    2010 年 35 巻 3 号 p. 515-517
    発行日: 2010/09/01
    公開日: 2014/05/13
    ジャーナル フリー
    Low-temperature gas adsorption studies have been carried out on six two-dimensional microporous Porphyrin Coordination Lattices (PCL) constructed from (metallo)-porphyrin ligands and dinuclear paddlewheel motif; [RuII,II2(MTCPP)]n, [RuII,III2(MTCPP)X]n and [Rh2(MTCPP)]n (M= H2, Zn; TCPP=4, 4', 4'', 4'''-(porphine-5, 10, 15, 20-tetrayl)tetrakis benzoic acid)). The PCL possess large surface areas in the range of 393.2 - 1168.9 m2/g, pore diameter in the range of 4.6 -5.2 Å and hydrogen adsorption capacities of 0.72 - 1.24 wt% at 77.4K and 1 atm. In particularly, [Ru2(ZnTCPP)]n took surface area of 1168.9m2/g, this value is the largest in 2-dimensional PCL structure which has been previously reported.
  • N.C. Gangi Reddy, K,N,M. Reddy, S. Lakshmi Reddy, Tamio Endo
    2010 年 35 巻 3 号 p. 519-527
    発行日: 2010/09/01
    公開日: 2014/05/13
    ジャーナル フリー
      Powdered plant materials of satavari root and amla are analyzed by ICP-MS, EPR, IR and NIR studies. The results indicate that copper is present in higher concentration when compared to other elements. An EPR study of satavari root and amla confirm the presence of Fe (III), Cu(II) and Cr(III). NIR results are due to carbonate and water fundamentals.
  • Takayuki Kodera, Kenichi Myoujin, Takashi Ogihara
    2010 年 35 巻 3 号 p. 529-532
    発行日: 2010/09/01
    公開日: 2014/05/13
    ジャーナル フリー
    Ag, Ni and Cu spherical fine powders were continuously produced by carrying out an aerosol process in a mass nanopowder production apparatus. The particle size, particle morphology, crystal phases and crystallinity of the as-prepared powders were characterized by SEM and XRD. The particles were nonaggregated and they exhibited a spherical morphology with a narrow size distribution.
  • Yuji OHISHI, Kaoru KIMURA, Masaaki YAMAGUCHI, Noriyuki UCHIDA, Toshihi ...
    2010 年 35 巻 3 号 p. 533-536
    発行日: 2010/09/01
    公開日: 2014/05/13
    ジャーナル フリー
    B12H16+ clusters were mainly grown through ion-molecule reactions of the diborane (B2H6) molecules in an external quadrupole static attraction ion trap. The composition of the clusters was confirmed from the mass spectrum. The structure of B12H16+ is considered to be nido structure. When trapped ions collide with neutral molecules, a part of kinetic energy is converted to the internal energy of trapped ion. The mean kinetic energy of trapped ions increased by adding DC voltage of the EQSIT. The analysis of mass spectrum of B12Hn+ clusters showed that the amount of B12H8+ increased. In order to increase the collision rate, He buffer gas was introduced into the EQSIT. As a result, B12H8+ was mainly produced. The required energy to form icosahedral B12Hn+ by the detachment of hydrogen molecule from B12Hn+2+ calculated at PBE0/6-311+G(d)//B3LYP/6-31G(d) level of theory showed that the required energy changes significantly between n≥8 and n≤6. This result explains the experimental result that B12H8+ is mainly produced by increasing kinetic energy of trapped ions.
  • Shigeru Itoh, G.M.Shafiur Rahman
    2010 年 35 巻 3 号 p. 537-541
    発行日: 2010/09/01
    公開日: 2014/05/13
    ジャーナル フリー
    Wood is an economical and renewable building material. However, untreated wood is subject to attack by insects, fire and decay fungi. To ensure long- term structural performance, wood must be protected from its natural and artificial hazards. The paper presents the description, results and result analysis for the effects of underwater shock wave treatment of wood on fire-retardant impregnation with a salt-containing agent and on wood fire performance. Underwater shock is generated in a water tank by means of explosion of detonating fuse which contains explosive. Shock wave with high -strength is applied to the wood samples on the basis of distance between the samples and detonating fuse. Treated samples are subjected to injection for fire retardant chemical impregnation. Shock treated wood is showed relative higher permeability, and improved flame proof performance in combustion test.
  • Masayoshi Tanaka, Saki Fujita, Ying Zhao, Tianwei Tan, Takatoshi Kinos ...
    2010 年 35 巻 3 号 p. 543-546
    発行日: 2010/09/01
    公開日: 2014/05/13
    ジャーナル フリー
    A sequential peptide having hydrophilic and hydrophobic amino acid residues, RADA16 (CH3CO-(Arg-Ala-Asp-Ala)4-NH2), forms a hydrogel in aqueous medium. The formation of the network structure would be based on hierarchical self-assembly; 1) formation of β-sheet structure, 2) construction of amphiphilic fibrous object, and 3) crosslinking between side chain by electrostatic interaction. The synthetic polymers such as polyelectrolyte and hydrophilic polymer mixed into the hydrogel medium gave influence to the physical property of the peptide hydrogel.
  • Yoshiaki Hashimoto, Masako Takasu, Shuhei Kawamoto, Tatsuki Oda, Hidem ...
    2010 年 35 巻 3 号 p. 547-553
    発行日: 2010/09/01
    公開日: 2014/05/13
    ジャーナル フリー
    We have made coarse-grained model for the tetra-PEG gel and analyzed the gel formation process and the structure of the tetra-PEG gel by using Brownian dynamics simulation. The simulations successfully obtain a reasonable reaction rate with respect to the simulation step. Calculating the number and types of cross-linkings before and after gelation, we found that gelation is caused by monomers with up to three cross-linkings. After gelation, most of the cross-linkings occur in the largest cluster, with cross-linking in the fourth reactive group. By studying mesh structure in the gel after cluster formation, we found the decrease of the size of the loops by cross-linkings. Particularly, loops of size eight were most abundant in our system, which can be one of the reasons for the high strength of the gel.
  • Ryutaro Tomita, Yuhei Natsume
    2010 年 35 巻 3 号 p. 555-561
    発行日: 2010/09/01
    公開日: 2014/05/13
    ジャーナル フリー
    Nanoelectronics based on graphene has become a fast growing field with a number of technical applications. In these circumstances, we perform numerical study of the existence of flat bands (FB) in graphene ribbons, in consideration of zigzag and Klein's bonds with periodic distribution for all cases in which N ≦10, where N denotes the period of the edge pattern. As a result, the electronic state at Fermi energy of graphene ribbons can be categorized into four types, depending on the period and the density of the Klein's bonds (NK), RNK/2N; These are type (i) where FB disappears, type (ii) ribbons that have only FB, type (iii) ribbons possessing only partially flat band (PFB), and type (iv) containing both FB and PFB. When Nincreases in type (iv), double degeneracy of PFB is maintained, while degeneracy of FB increases. Systems of N = 3n are classified into categories types (i) and (ii), while systems of N≠3n belong to types (iii) and (iv). We would like to emphasize that above properties for appearances and disappearances of PFB and FB are dominated only by numbers of Klein's bonds in corresponding unit cells for N periods. Namely, those are independent of positions of Klein's bonds. The relationship between those properties in ribbons and the role of Dirac K-points originating from graphene is discussed.
  • Masanori Shinohara, Hiroki Kawazoe, Taka-aki Kawakami, Takanori Inayos ...
    2010 年 35 巻 3 号 p. 563-566
    発行日: 2010/09/01
    公開日: 2014/05/13
    ジャーナル フリー
      Substrate bias effects on deposition process of amorphous carbon film during acetylene plasma were investigated by using infrared absorption spectroscopy in multiple internal reflection geometry (MIR-IRAS). IRAS spectra showed that the relative density of sp3-hydrocarbon was decreased with substrate bias while that of the sp2-C and that of sp-CH were increased. Furthermore, the film was formed with the transformation of the adsorbed species generated in acetylene plasma. It suggested that owing to substrate bias, the polymer components were etched and the density of carbon-carbon bonds was increased during deposition.
  • Masanori Shinohara, Shuai Zhang, Kenji Kotani, Kazuhiko Akaki, Yoshino ...
    2010 年 35 巻 3 号 p. 567-570
    発行日: 2010/09/01
    公開日: 2014/05/13
    ジャーナル フリー
    The plasma was generated in organic solvents (ethanol and n-hexane mixture) in order to coating inside the narrow tubes. From measurements of discharge current, plasma is easily generated in ethanol, but the generation of plasma has difficulty in n-hexane. The ratio of mixture of 1:1 is suitable to film deposition, since ethanol is used for plasma generation and hexane is used for source of the films. FTIR spectra exhibited the deposited films are typically polymer-like amorphous carbon (PLC) films.
  • Rubin Ye, Youhei Uchida, Wei Zheng
    2010 年 35 巻 3 号 p. 571-574
    発行日: 2010/09/01
    公開日: 2014/05/13
    ジャーナル フリー
    RF discharge argon plasma was utilized to thermal annealing of stranded aluminum alloy wire under atmospheric pressure (AP). Experimental results demonstrated that, in additional to surface cleaning, the AP plasma could also be applied to effectively treating the bulk of a material by using the thermal energy of the plasma. Dependences of the mechanical properties of the wire, the wire temperature, and the energy efficiency on annealing time and gas flow rate were investigated. Heating mechanism in the RF plasma annealing process was proposed.
  • Giichiro Uchida, Satoshi Uchida, Hiroshi Kajiyama, Tsutae Shinoda
    2010 年 35 巻 3 号 p. 575-578
    発行日: 2010/09/01
    公開日: 2014/05/13
    ジャーナル フリー
      We present the measurement on SrO- and SrCaO-cathode PDP operated at lower voltage. SrO- and SrCaO-cathode PDP attain high luminous efficacy at low voltage, where the breakdown voltage is 30% lower than that of the ordinal MgO-cathode PDP. Emission measurements clearly demonstrate that the SrO- and SrCaO-cathode PDP have a weak discharge with small current flow and low electron energy, which is appropriate for high luminous efficacy of PDP. Also, the direct measurement of VUV radiation from a PDP small cell shows that increasing Xe gas pressure leads to a drastic increase in excimer radiation (172 nm) from Xe molecule, which also considerably contributes to the high luminous efficacy of PDP.
  • T. Nagata, M. Haemori, J. Anzai, T. Uehara, T. Chikyow
    2010 年 35 巻 3 号 p. 579-582
    発行日: 2010/09/01
    公開日: 2014/05/13
    ジャーナル フリー
      We have demonstrated the growth of the GaN film by near-atmospheric plasma-assisted chemical vapor deposition (AP-CVD). Pure nitrogen plasma can be generated stably using an alternating pulsed voltage system that applies an alternating pulsed voltage between two parallel plate electrodes. Using this plasma as a nitrogen source, we can obtain crystalline GaN film above 330℃. Blow 330℃, GaN film was amorphous structure due to carbon contamination. To overcome this issue, hydrogen diluted nitrogen gas was used as reactive gas. Optical emission spectrum measurement revealed that the hydrogen diluted nitrogen near-atmospheric plasma decomposed triethylgallium (TEG), which was used as Ga metal precursor, even at room temperature. Using this plasma as a nitrogen source, deposited GaN films showed the epitaxial growth on a sapphire substrate above the growth temperature of 170℃. From the results obtained, we found that AP-CVD has a great potential of being employed in GaN film fabrication under high nitrogen partial pressure and at low temperature.
  • Tamiko Ohshima, Takeaki Matsunaga, Hiroharu Kawasaki, Yoshiaki Suda, Y ...
    2010 年 35 巻 3 号 p. 583-587
    発行日: 2010/09/01
    公開日: 2014/05/13
    ジャーナル フリー
    We deposited indium tin oxide (ITO) thin films by pulsed laser deposition (PLD) under various deposition conditions such as different levels of laser fluence and ambient oxygen gas pressure, while maintaining the substrate temperature at room temperature. We investigated the optical, structural, and electrical properties of the films as a function of the deposition conditions. We found that the variation of film properties is more dependent on oxygen gas pressure than on laser fluence. High quality ITO thin films with low electrical resistivity of 2-4 × 10-4 Ω・cm and high optical transmittance of over 80% in the visible region are deposited on a glass substrate at room temperature under laser fluence above 4 J/cm2 and oxygen gas pressure of 1 Pa. We experimentally produced an electrochromic device (ECD) using ITO coated glass substrate deposited at optimal deposition conditions. It is shown that ECD is colored by applied voltage and bleached when the voltage is reversed.
  • Shinichi Tashiro, Minoru Miyata, Manabu Tanaka, Kenei Shin, Kuniaki Ta ...
    2010 年 35 巻 3 号 p. 589-592
    発行日: 2010/09/01
    公開日: 2014/05/13
    ジャーナル フリー
    As an action to an environmental problem, car companies attempt to reduce the weight of a car body maintaining strength by adopting a tailored blank which joins different thick metal plates. Keyhole welding with the plasma arc is generally used for the tailored blank, because this process enables high speed welding suppressing thermal distortions. A weld defect such as an undercut occurs if a welding current is higher in order to increase the welding speed, since the arc pressure is enhanced due to increase in plasma jet velocity. The numerical analysis of the plasma arc is able to assist to overcome such a phenomenon. The analyses have been conducted by many researchers in order to understand the mechanism of keyhole welding with the plasma arc and design the suitable plasma torch. In this study, we have built a unified model considering the convection flow in the weld pool and examine phenomenon in the plasma and the weld pool. A keyhole diameter determined by the pressure balance on the keyhole surface was estimated and compared with an experiment result. As a result, the keyhole diameter obtained from the simulation approximately agreed with that of the experiment and the reliability of the simulation result was confirmed.
  • Y. Tsujimura, H. Terasaki, K. Yamamoto, S. Tashiro, M. Tanaka
    2010 年 35 巻 3 号 p. 593-596
    発行日: 2010/09/01
    公開日: 2014/05/13
    ジャーナル フリー
    In order to investigate effects of metal vapor on the plasma state in welding process, electron temperature in helium Gas Tungsten Arc (GTA) plasma during welding was measured by using the laser scattering method. Furthermore, number density distributions of metal neutrals and ions were also measured by using the spectroscopic analysis. Our results showed that plasma during welding consisted of two plasma regions, namely, pure helium plasma region and quasi-metal plasma region.
  • Yuki Kawashima, Kenta Nakahara, Hiroshi Sato, Giichiro Uchida, Kazunor ...
    2010 年 35 巻 3 号 p. 597-599
    発行日: 2010/09/01
    公開日: 2014/05/13
    ジャーナル フリー
    We have synthesized size-controlled Si nanoparticles using multi-hollow discharge plasma CVD and have assembled Si quantum dot-sensitized solar cells which are candidates for multiple exciton generation solar cells of the third generation photovoltaics. We have demonstrated extraction of carriers from Si nanoparticles to an external circuit using the Si quantum dot-sensitized solar cells.
  • Nilesh J. Vasa, Iyamperumal A. Palani, Makaram Singaperumal, Tatsuo Ok ...
    2010 年 35 巻 3 号 p. 601-606
    発行日: 2010/09/01
    公開日: 2014/05/13
    ジャーナル フリー
    An application of a pulsed, solid-state laser with a Gaussian and flat-top beam profiles is considered for annealing and nano-texturing of amorphous-silicon (a-Si) films. Investigations are performed with the third harmonics (355 nm), the second harmonics (532 nm) of the Nd3+:YAG laser. To crystallize and subsequently induce texture, a-Si films are treated by spatial-overlapping of the laser spots on the surface by 50% and 90% of its size. Based on surface morphology studies, a large amount of surface peaks are observed with 90% overlap than that with 50% overlap. Samples treated with 90% overlap show a higher absorbance as compared to the 50% overlap and an improvement in photoconductivity is also observed. Nd3+:YAG laser beam with the flat-top beam profile and 90% overlap during annealing is appropriate for the photovoltaic application.
  • Mitsuru Sasaki, Wahyudiono , Motonobu Goto
    2010 年 35 巻 3 号 p. 607-610
    発行日: 2010/09/01
    公開日: 2014/05/13
    ジャーナル フリー
    In this work, reactions of phenol were carried out in supercritical argon (critical temperature, Tc: 150.7 K, critical pressure, Pc: 4.8 MPa) with pulsed discharge plasma to understand reaction characteristics and to evaluate possibility that this technique will be applicable for a new “green” polymerization technique of functional polymeric materials. Experiments in subcritical water or in supercritical argon were conducted through the operation of a specially-designed SUS316 batch-type reactor (inner volume: 900 mL) at 373-523 K and 1-25 MPa, or at 303-373 K and 5-15 MPa, respectively. The electrode configuration consisted of a point (negative electrode) and a planar surface (positive electrode), which were made of tungsten and stainless steel, respectively. The distance between the two electrodes was fixed at 1 mm. Two kinds of power supply devices (BPFN and MPC) were employed. As results using a BPFN, it was found that reaction behavior in subcritical water at 373-523 K, 1- 25 MPa with less than 4000 times pulsed discharges basically similar to that in supercritical argon, but polymerized products of phenol could be obtained under larger pulsed discharge times like 5000 times at identical conditions. In contrast, phenol could be converted into hydroquinone but no polymerized product could be confirmed in supercritical argon.
  • Qiang Ma, Akihisa Ogino, Takafumi Matsuda, Masaaki Nagatsu
    2010 年 35 巻 3 号 p. 611-615
    発行日: 2010/09/01
    公開日: 2014/05/13
    ジャーナル フリー
    ZnO nano-particles with a diameter of 10-20 nm were fabricated under oxygen and helium mixture plasma circumstance by evaporating Zn target using pulsed laser ablation. Cathodoluminescence technique, combined with transmission electron microscopy, X-ray diffraction and energy-dispersive spectrometer, was applied to study luminescence property and crystalline structure of ZnO nano-particles. Varying the oxygen partial pressure from 300 Pa to 1000 Pa, the intensity of UV peak increased and dominated in cathodoluminescence spectrum, indicating the presence of a good crystalline structure in the inner layer of ZnO nano-particles. The ratio of the intensities corresponding to the UV peak and the green-yellow peak of ZnO nano-particles synthesized in mixture (oxygen and helium) plasma was higher than that corresponding to the nano-particles fabricated in oxygen plasma.
  • Daisuke Ohba, Chien Hui Lai, Shun-suke Sato, Zeguo Tang, Hajime Shirai
    2010 年 35 巻 3 号 p. 617-620
    発行日: 2010/09/01
    公開日: 2014/05/13
    ジャーナル フリー
    The film deposition study of amorphous and microcrystalline Si (a-Si:H, μc-Si:H) was performed by rf plasma-enhanced chemical vapor deposition of a Si3H8 and H2 mixture for Si thin-film solar cells. Highly photoconductive a-Si:H and μc-Si:H films were fabricated at 3-6Å/s. The μc-Si:H films showed preferential crystalline orientation ratio of (220) to (111), I220/I111 of 2.5. The pin a-Si:H and μc-Si;H thin-film solar cells exhibited a efficiency of 6.2% and 3.9%, respectively, despite of the use of a single chamber system. The plasma-annealed ZnO:Al capping p+-a-Si layer further improved the performance of both a-Si:H and μc-Si:H thin-film solar cells.
  • Satomi Tajima, Shouichi Tsuchiya, Masashi Matsumori, Shigeki Nakatsuka ...
    2010 年 35 巻 3 号 p. 621-625
    発行日: 2010/09/01
    公開日: 2014/05/13
    ジャーナル フリー
    Local reduction of the copper oxide film was performed by an atmospheric-pressure inductively coupled plasma (AP-ICP) microjet and the fundamental characteristics of the removal process were studied. CuO and Cu2O films were formed on the sputtered Cu surface by thermal annealing. The sample was then exposed to the Ar-H2 AP-ICP microjet. The chemical composition, morphology, and the film thickness before and after the plasma treatment were analyzed by XPS, optical microscopy, and SEM/EDX. CuO and Cu2O were reduced to form porous Cu at the speed of 380 nm/min. Heterogeneous reduction patterns inside the Cu2O layer were observed due to the fast diffusion of H atoms through the narrow gap between the columnar structures.
  • Takuma Seki, Ryo Nakajima, Motosuke Naoki
    2010 年 35 巻 3 号 p. 627-630
    発行日: 2010/09/01
    公開日: 2014/05/13
    ジャーナル フリー
    An expanded theory based on the hydrogen-bond configuration has been applied to compounds with the structure analogous to the surface in adsorbents, ketone and the systems of ketone/aromatic alcohol. The melting temperature depression of pure crystal and co-crystal of the systems were well reproduced by the theory. The analysis revealed the hydrogen-bond characteristics of the systems and predicted negative mixing heats.
  • S. Nagarajan, N. Rajendran
    2010 年 35 巻 3 号 p. 631-634
    発行日: 2010/09/01
    公開日: 2014/05/13
    ジャーナル フリー
      Potentiodynamic anodic polarisation and Dynamic Electrochemical Impedance Spectroscopic (DEIS) measurements were carried out on type 316L stainless steel (SS) and alloy 31 in natural sea water in order to assess the pitting corrosion resistance. DEIS measurements were performed over a wide range of potentials covering the corrosion potential, passive region, breakdown region and dissolution region. It was shown that the impedance measurements in potentiodynamic conditions allow instantaneous investigation of changes in passive layer with potential. The impedance spectra of various potential regions were also discussed. From the above studies, the pitting corrosion resistance of the alloys 31 was higher than 316L SS; due to the higher contents of nitrogen, chromium and molybdenum.
  • Takashi SUZUKI, So TAJIMA
    2010 年 35 巻 3 号 p. 635-638
    発行日: 2010/09/01
    公開日: 2014/05/13
    ジャーナル フリー
    Co/SiO2 catalyst shows an activity for the Fischer-Tropsch reaction. In order to improve the catalytic activity for the reaction, addition of third component was tried in the Co/SiO2 catalyst system. When yttrium oxide, cerium oxide, and lanthanum oxide was added to the Co/SiO2 catalyst, the rate of the Fischer-Tropsch reaction was improved. Particularly, upon doping yttrium oxide to Co/SiO2, the rate was enhanced 1.7- fold, as much as that in the case using plain Co/SiO2 catalyst. It was conjectured that the phenomenon was caused by increase active sites which would be induced by third component such as yttrium oxide.
  • Seiichiro Takahashi, Ryuichi Komatsu
    2010 年 35 巻 3 号 p. 639-642
    発行日: 2010/09/01
    公開日: 2014/05/13
    ジャーナル フリー
    Nodules, generated frequently on the surface of an indium tin oxide (ITO) target by sputtering, have caused severe degradation of the target. The mode of occurrence and the formation mechanism of nodules have been investigated to determine the conditions for preventing the occurrence of the nodules and to extend the lifetime of the target.
  • Kazuhiro Kitamura, Yukiharu Yoshimi
    2010 年 35 巻 3 号 p. 643-645
    発行日: 2010/09/01
    公開日: 2014/05/13
    ジャーナル フリー
      The rolling reduction of a cast shape memory alloy plate from self-propagating high temperature synthesis (SHS) ingot was investigated. The composition of SHS ingot is Ti-50.8at%Ni. Differential scanning calorimetry (DSC) and tensile test specimens were cast by lost-wax process from SHS ingot. Specimens were cold rolled by rolling machine. The heat treatment conditions were as cast, 400℃-60min, 500℃-60min and 600℃-60min for DSC and tensile test specimens. Transformation temperatures were measured by DSC. Mechanical properties were measured by a tensile test at several temperatures. The effect of rolling reduction was investigated this study. The shape memory characteristics similar to the Ti-Ni bulk material appears by 10% rolling reduction.
  • Machiko Takigami, Naotsugu Nagasawa, Akihiro Hiroki, Noboru Kasai, Fum ...
    2010 年 35 巻 3 号 p. 647-650
    発行日: 2010/09/01
    公開日: 2014/05/13
    ジャーナル フリー
    There are many swine farmers near the rivers in Gunma Prefecture and the secondary treated water from the farmers comes into the river. The color of the drainage is dark brown. Although there is no regulation of chromaticity of the waste water from the farmers, one of the biggest concerns of the farmers is the color of the waste water. An absorbent was prepared by radiation grafting of cationic monomer on fiber to reduce the color. The color was easily removed using the absorbent. COD of the waste water was also reduced after decolorization. The decrease in chromaticity using absorbents depended on the degree of grafting of the absorbents. Maximum decrease in 4 h was obtained when absorbent with 86% degree of grafting was used. The absorbed colored substances on the absorbent were easily desorbed using salt solution. Colored substances were precipitated adding acid to the desorbed solution. The colored substances in the secondary treated water were estimated to be humic substances. The absorbent and desorbent after removing colored substances could be used repeatedly. Environmentally-friendly new system is proposed to treat secondary treated water from livestock urine waste.
  • T. Yamamoto, M. Kanda, H. Cho, T. Sakuma
    2010 年 35 巻 3 号 p. 651-654
    発行日: 2010/09/01
    公開日: 2014/05/13
    ジャーナル フリー
      This study discusses the suitable heat treatment condition for Ti-50.3at%Ni shape memory alloy. Tensile and tensile loading-unloading tests carried out using the heat-treated Ti-50.3at%Ni wire at the temperatures of Af+30K, Af+40K and Af+50K which are 30K, 40K and 50K higher than austenite finish temperature Af, respectively, and the effects of heat treatment temperature (HTT) and environmental temperature on thermomechanical properties has been investigated. The breaking strains of HTT=673K, 723K and 773K are almost the same value and do not vary in the temperature range from Af +30K to Af + 40K. However, the breaking strain of HTT=773K rapidly increases at Af + 50K. There is hardly difference of the plastic strain between HTT=673K and 773K under the applied strain of 5%. However, the plastic strain of HTT=773K is lager than that of HTT=673K under the applied strain of 10%. The recoverable strain energy of HTT=673K is twice as large as that of HTT=773K both under the applied strain of 5% and 10%. This means that the Ti-50.3at%Ni wire heat-treated at 673K can store almost twice as much energy as the wire heat-treated at 773K.
  • Jun-ichi Kawamoto, Yuhji Yagi, Jun Satake, Toshio Takayama, Hiroshi Ya ...
    2010 年 35 巻 3 号 p. 655-658
    発行日: 2010/09/01
    公開日: 2014/05/13
    ジャーナル フリー
    The electrical conductivity and dielectric properties of the Zr0.8Ln0.2O1.9 (Ln = Nd, Sm, Eu, Gd, Dy, Ho, Er, Tm, Yb, Lu) system which have a cubic fluorite-type structure were investigated in order to clarify a dynamic property of oxygen vacancy in oxide-ion conductors. The frequency dependences of dielectric constants (εr') were successfully explained by the superposition of Debye-type polarizations and electrolyte-electrode interfacial polarizations. The ac conductivity (σac) agreed with the calculated values using the dielectric parameters. It was found that the compositional dependence of dielectric properties was similar to that of σac.
  • Jun Satake, Toshio Takayama, Hiroshi Yamamura
    2010 年 35 巻 3 号 p. 659-663
    発行日: 2010/09/01
    公開日: 2014/05/13
    ジャーナル フリー
    Relationship between oxide ion conduction and dielectric relaxation in the Ce1-xYxO2-x/2 system (0≦x≦0.5) was investigated in order to clarify the dynamic properties of oxide ion conduction. The frequency dependence of dielectric constant was explained by the superposition of Debye-type polarization due to dopant-vacancy associates and charge current on electrolyte-electrode interface. The frequency dependence of ac conductivity was also explained by use of the dielectric parameters obtained from the numerical analysis of dielectric constant. Additionally, the polarization hysteresis curves of the oxide ion conductor were also measured to investigate the Debye-type dipoles in detail. As a result, it was found that the observed remanent polarizations have a close relation with the polarization of dopant-vacancy associates.
  • Yuhei Miyazaki, Yusuke Kataoka, Wasuke Mori
    2010 年 35 巻 3 号 p. 665-667
    発行日: 2010/09/01
    公開日: 2014/05/13
    ジャーナル フリー
    We investigated nitrogen and hydrogen gas adsorption properties of microporous ruthenium coordination polymers constructed from RuII/III2 paddle wheel motif and dicarboxylic organic linkers such as terepthalic acid, fumaric acid, muconic acid and succinic acid. In nitrogen gas adsorption measurements, we calculated adsorption parameters such as surface area (Langmuir ), pore volume and pore diameter. The relation between adsorption parameters and maximum amount of hydrogen uptake was discussed.
  • Arkadiusz Malinowski, Masaru Hori, Makoto Sekine, Wakana Takeuchi, Lid ...
    2010 年 35 巻 3 号 p. 669-674
    発行日: 2010/09/01
    公開日: 2014/05/13
    ジャーナル フリー
    A technology of manufacturing of carbon nano-wall films (CNWs) as well as a methodology for control of their properties are briefly described. Short channel effects (SCEs) are discussed. Single carbon nano-wall field effect transistor (SCNWFET) is proposed and modeling considerations using technology computer aided design (TCAD) software are explained. Device performance estimation and immunity to SCEs are given. Basic electrical characteristics and parameters important for application in integrated circuits are discussed.
  • Hidenori Aihara, Tsuyoshi Tanaka, Masaru Satou, Tetsu Yamakawa
    2010 年 35 巻 3 号 p. 675-680
    発行日: 2010/09/01
    公開日: 2014/05/13
    ジャーナル フリー
    The photoluminescence and electron drift mobility of newly synthesized 1,3,5-triazine derivatives were investigated. 1,3,5-Triazine derivatives with one or two 4-(arylethynyl)phenyl groups had single photoluminescence peaks in the blue region, 405-452 nm, in the deposited films. Time-of-flight measurement revealed that electron transport in the films of certain 1,3,5-triazine derivatives was non-dispersive and electron drift mobilities were in the range of 10-5-10-4 cm2 V-1 s-1. OLED devices incorporating 1,3,5-triazine derivatives in the emitting layer had pure blue luminescence at 437 nm and 444 nm. Moreover, these compounds were also able to be used as an electron-transport layer.
  • Hajime Kiyono, Yasunobu Noritake, Shiro Shimada
    2010 年 35 巻 3 号 p. 681-684
    発行日: 2010/09/01
    公開日: 2014/05/13
    ジャーナル フリー
    To improve oxidation resistance to water vapor in high-temperature environment, alumina (Al2O3) film is coated on β-sialon (z=3) ceramic. Aluminum alkoxide (Al(OBt)3) with diethanolamine and ethanol and Al2O3 sol with ethanol were used as precursor solutions. These precursors were coated on β-sialon substrate by dip coating method and the coated sample was heated at 600℃ for 1 h (as-coated sample). The as-coated sample was heat-treated at 1300℃ in Ar/O2 (95/5 vol%) for 2 h and subsequently treated in Ar for 10 h (heat-treated sample). The samples were oxidized in Ar/O2/H2O (8/2/90 vol%) at 1200℃ for ~100 h. The heat-treated samples showed high oxidation resistance to water vapor comparing with as-coated sample.
  • Motofumi Yamada, Takayuki Kodera, Takashi Ogihara
    2010 年 35 巻 3 号 p. 685-688
    発行日: 2010/09/01
    公開日: 2014/05/13
    ジャーナル フリー
    Spherical C/Li4Ti5O12 anode powders were prepared by spray pyrolysis with aqueous solution. The particle characteristics of C/Li4Ti5O12 powders were determined by SEM, XRD and DTA-TG. C/Li4Ti5O12 anode powder had a spherical morphology with non aggregation and porous structure. The carbon content was around 13 wt%. XRD analysis revealed that the spinel phase was obtained by heating at 750 ℃ under N2 atmosphere. The discharge capacity of C/Li4Ti5O12 was 160 mAh/g at 1C. That of C/Li4Ti5O12 decreased to 90 mAh/g at 20 C. 96 % of initial discharge capacity was maintained at 1 C after 100 cycles. 85 % of it was maintained at 20 C after 300 cycles.
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