巻号一覧
52 巻, 12 号
December
選択された号の論文の15件中1～15を表示しています
- |<
- <
- 1
- >
- >|
研究
研究
-
橋井 光弥, 金武 直幸2005 年 52 巻 12 号 p. 869-873
発行日: 2005年
公開日: 2006/04/28
ジャーナル オープンアクセスThe phase characterization of N2-gas-atomized Mn-Si powder was examined by comparing with those of an ingot and mechanically milled (MM) powder. The atomized powder showed single phase of MnSi1.7. A small amount of MnSi phase was precipitated by annealing at high temperature. The results shows that the atomizing process is very effective to obtain the single phase of MnSi1.7 compared to other processes. The MM powder from MnSi1.7 ingot also showed single phase of MnSi1.7. A MnSi phase was precipitated on the MM powder by 743 K-0 s annealing. On the other hand, the atomized powder preserved MnSi1.7 single phase after same annealing. Precipitation of MnSi phase was observed after 1000 K-0 s annealing on the atomized powder.抄録全体を表示PDF形式でダウンロード (715K) -
Takao Funayama, Junya Takahashi, Atsunori Kamegawa, Hitoshi Takamura, ...2005 年 52 巻 12 号 p. 874-878
発行日: 2005年
公開日: 2006/04/28
ジャーナル オープンアクセスPresent paper describes the effects of the Mg content on the occurrence of HDDR phenomena as well as the microstructural evolution in Al-(3-7.8 mass%)Mg alloys. It was found that the HDDR phenomena take place in all those alloys, and grain size of the alloy turned into a several 10 nm after HDDR treatments such as heat-treatment at 350°C under hydrogen pressure of 7.5 MPa for 72 h, in following by the hydrogen desorption treatment at 350°C for 4 h in vacuum. The refined grain size of Al-3.0 mass% Mg alloy was observed to be largest among there alloys. However, it should be emphasized that small content of Mg (3 mass%) is able to induce the HDDR phenomena associated with the nano-order grain refinements in Al-Mg alloys. This could be the first observation of HDDR phenomena which occur in Al-3 and 5 mass% Mg alloys, and are effective for yielding the nano-order fine grain size.抄録全体を表示PDF形式でダウンロード (1296K) -
金田 功, 坂本 典正2005 年 52 巻 12 号 p. 879-882
発行日: 2005年
公開日: 2006/04/28
ジャーナル オープンアクセスEffects of powder properties of the filler, including the particle size, the specific surface area and the lattice strain, on the dielectric permittivity and Q of ceramics-polymer composites have been investigated in order to achieve composites with high ε and Q.
Ca0.65Sr0.35TiO3 was chosen as the material of the ceramics dielectric filler for its high ε and Q at maicrowave frequencies. Dielectric fillers of Ca0.65Sr0.35TiO3 with various particle sizes, specific surface areas, and lattice strains were prepared.
The ceramics-polymer composites were prepared using these fillers, and the dielectric properties of the composites were evaluated at 2 GHz. The dielectric properties of the composites were strongly influenced by the powder properties of the filler, despite that the fillers have the same composition. Generally, lower specific surface area and lower lattice strain of the filler lead to higher ε and Q of the composites.抄録全体を表示PDF形式でダウンロード (685K)
特集 高精度電子部品材料
総報
-
原田 真二2005 年 52 巻 12 号 p. 884
発行日: 2005年
公開日: 2006/04/28
ジャーナル オープンアクセスPDF形式でダウンロード (128K)
受賞記念講演
-
山下 洋八2005 年 52 巻 12 号 p. 885-890
発行日: 2005年
公開日: 2006/04/28
ジャーナル オープンアクセスEcho ultrasound diagnostic equipment has been used for last 30 years. In this application, ultrasonic probes play an important role to realizing a good image on screen. In this article, the probe structure and materials used for the device are briefly introduced. In addition, many powders used for ultrasonic acoustic materials, such as lens, matching layer and backing are also introduced. High dielectric constant and high piezoelectric constant of lead-perovskite relaxor multicomponents system ceramics Pb(Sc1/2Nb1/2)O3-Pb(Mg1/3Nb2/3)O3-Pb(Ni1/3Nb2/3)O3-(Pb,SrBa)(Zr,Ti)O3 (PSN-PMN-PNN-PSZT) with high dielectric constant ε33T/ε0=5,000-7,200 and large planar mode electromechanical coupling factor (EMCF) kp > 69% near the morphotropic phase boundary are summarized. Some new materials, piezoelectric single crystals and low-attenuation acoustic lens material are also introduced.抄録全体を表示PDF形式でダウンロード (1608K)
研究
-
堺 英樹2005 年 52 巻 12 号 p. 891-895
発行日: 2005年
公開日: 2006/04/28
ジャーナル オープンアクセスTiO2 powders prepared by Chloride process under conventional conditions were found to consist of anatase-type particles and rutile-type particles. Conventional TiO2 powders are mixtures of these two different size-range groups of particles, common TiO2 powders has a substantial particle distribution. Two types of ultra fine TiO2 powders at a same level of particle size, namely anatase rich type (ratio of anatase to rutile > 90%) and rutile rich type (ratio of rutile to anatase > 90%), were synthesized by using fine tuned process control. Both powders were synthesized to have SSA of about 30 m2/g and an average particle sizes to be about 40 nm. The particle size distributions of both powders were found to be much less than conventional TiO2 powders of this size. These TiO2 powders were suitable for the solid state reaction of narrow particle distribution BaTiO3 ultra-fine powders for high quality MLCC.抄録全体を表示PDF形式でダウンロード (1287K) -
Wataru Sakamoto, Yu-ki Mizutani, Mio Yamada, Naoya Iizawa, Daichi Toga ...2005 年 52 巻 12 号 p. 896-901
発行日: 2005年
公開日: 2006/04/28
ジャーナル オープンアクセス(Bi,La)4Ti3O12 thin films of Bi-layered perovskite structure were fabricated on Pt/TiOx/SiO2/Si substrates by chemical solution deposition (CSD) method. The crystallization and microstructure of the (Bi,La)4Ti3O12 thin films markedly depended upon the kind of used La-sources when the precursor solutions were prepared. Synthesized Bi3.35La0.75Ti3O12 (BLT) thin films from the precursor solution using a La(OiPr)3 as a starting material revealed (00l ) preferred orientation and anisotropic grain growth. On the other hand, BLT thin films using a La(OAc)3 as a La-source showed random orientation with a strong (117) reflection and homogeneous microstructure. This is due to the difference in the pyrolysis and crystallization behaviors of the precursor films. The BLT thin films exhibited the well-saturated ferroelectric P-E hysteresis loops. The BLT thin film prepared from a La-acetate showed the Pr value of 15.6 μC/cm2, which was higher than that of the BLT thin films from a La-alkoxide.抄録全体を表示PDF形式でダウンロード (1041K) -
Wataru Sakamoto, Yukinobu Yura, Toshiaki Yamaguchi, Koichi Kikuta, Shi ...2005 年 52 巻 12 号 p. 902-906
発行日: 2005年
公開日: 2006/04/28
ジャーナル オープンアクセスCa- and V-codoped Sr2(Nb,Ta)2O7 thin films have been fabricated by the chemical solution deposition. Homogeneous and stable precursor solutions were prepared by controlling the reaction of starting metal-organic compounds. The improvement of ferroelectric properties of the Sr2(Nb,Ta)2O7-based films were achieved through the V doping to the (Sr0.9Ca0.1)2(Nb0.3Ta0.7)2O7. In the composition range of 0≤x≤0.15, (Sr0.9Ca0.1)2{(Nb0.3Ta0.7)1-xVx}2O7 (SCNTVx) thin films crystallized in the single-phase of (Sr,Ca)2(Nb,Ta)2O7 without any formation of the second phase. The crystallization temperature of the layered perovskite SCNTVx thin films on Pt/Ir/Ti/SiO2/Si substrates was found to be below 700°C. Synthesized SCNTVx thin films showed the low dielectric constant with low loss tangent over wide frequency and temperature regions. Furthermore, the SCNTVx thin films with an optimum amount of V could be crystallized at 650°C and exhibited the typical ferroelectric hysteresis loop with a Pr of 0.8 μC/cm2 and a Ec of 75 kV/cm.抄録全体を表示PDF形式でダウンロード (636K)
特集 導電性セラミックスの新展開
総報
-
一ノ瀬 昇2005 年 52 巻 12 号 p. 908
発行日: 2005年
公開日: 2006/04/28
ジャーナル オープンアクセスPDF形式でダウンロード (68K)
研究
-
増野 敦信, 寺嶋 孝仁, 島川 祐一, 高野 幹夫2005 年 52 巻 12 号 p. 909-912
発行日: 2005年
公開日: 2006/04/28
ジャーナル オープンアクセスWe examined electroresistive effects of epitaxial La0.67Ca0.33MnO3(LCMO) thin films deposited on LaAlO3(100)(LAO) substrates. The films are under compressive strain due to lattice mismatch between LCMO (a ≈ 3.86 Å) and LAO (a ≈ 3.79 Å). To relax this strain, our films appear to consist of regions of high-strained charge-ordered insulator (COI) and low-strained ferromagnetic metal (FMM) at low temperatures. By using a micro-fabricating process to the samples, large current density can be applied effectively. These mixed-phase inhomogeneous thin films showed an interesting current-induced first-order transition from COI to FMM. This non-reversible behavior is pronounced with increasing maximum applied current. These results strongly suggest that spin-polarized electrons in FMM are injected into COI; as a result, antiferromagnetic localized electron spins are forced to align ferromagnetically.抄録全体を表示PDF形式でダウンロード (331K) -
高田 和英, 東 正樹, 島川 祐一, 高野 幹夫2005 年 52 巻 12 号 p. 913-917
発行日: 2005年
公開日: 2006/04/28
ジャーナル オープンアクセスMultiferroic materials where ferromagnetism and ferroelectricity coexist are rare. We have succeeded in synthesizing new multiferroic materials Bi2M MnO6 (M = Ni, Co) at high pressure of 6 GPa. The crystal structures of these compounds are a heavily distorted double-perovskite (space group C2), with M 2+ and Mn4+ ions ordered in a rock-salt configuration. The monoclinic unit cell of Bi2NiMnO6 is a = 9.4630(1), b = 5.42553(8), c = 9.5352(1) Å, and β= 107.840(1)°, and that of Bi2CoMnO6 is a = 9.4886(2), b = 5.4444(1), c = 9.5678(2) Å, and β= 107.603(1)°. A polarized 6s2 lone pair in Bi3+ causes the noncentrosymmetric structural distortion, which leads to ferroelectric property. On the other hand, NaCl-type ordering of M 2+ with eg electrons and Mn4+ without eg electron produces ferromagnetic exchange paths, -M 2+-O2--Mn4+-, according to the Kanamori-Goodenough rules. The ferroelectric and the ferromagnetic transition temperatures of Bi2NiMnO6 are 455 and 140 K, respectively. The ferroelectric transition temperature of Bi2CoMnO6 is above 600 K, while the ferromagnetic transition temperature is 95 K.抄録全体を表示PDF形式でダウンロード (660K) -
島村 清史, Encarnación G. Víllora, 青木 和夫, 北村 健二, 一ノ瀬 昇2005 年 52 巻 12 号 p. 918-922
発行日: 2005年
公開日: 2006/04/28
ジャーナル オープンアクセスLarge size single crystals of β-Ga2O3 with 1 inch in diameter have been grown by the floating zone technique. Wafers have been cut and fine polished in the (100), (010) and (001) planes. These were highly transparent in the visible and near UV, as well as electrically conductive, indicating the potential use of β-Ga2O3 as a substrate for optoelectric devices operating in the visible/near UV and with vertical current flow. Epitaxial growth of nitride compounds by the metalorganic vapor phase epitaxy (MOVPE) technique is demonstrated on β-Ga2O3 single crystal substrates. High-quality (0001) GaN epi-layers with a narrow bandedge luminescence are obtained using a low temperature conductive buffer layer. InGaN multi-quantum well (MQW) structures were also successfully grown. The first blue light-emitting diode (LED) on β-Ga2O3 with vertical current injection is demonstrated.抄録全体を表示PDF形式でダウンロード (1660K) -
堀田 勝喜, 今泉 勇人, 佐々木 晃一, 渡辺 康夫, 廣瀬 治男2005 年 52 巻 12 号 p. 923-927
発行日: 2005年
公開日: 2006/04/28
ジャーナル オープンアクセスThe fundamental properties of a single layer type microwave absorber using the Bi-system superconductors for the X band (8-12.5 GHz) have been examined. The samples were prepared by crushing the Bi(Pb)-2223 superconductors exhibiting Tc(end)=93.4 K into powders ( < 50 μm) and mixing with the epoxy resin at different ratios from 0 to 50 vol%. The complex reflective intensities of samples were measured by using a vector network analyzer in frequency range from 8.8 to 10.4 GHz at room temperature (300 K) and at liquid nitrogen temperature (77 K). The difference of the complex reflective intensity value between the sample and a metal plate was defined as our reflection loss (R.L.). The electromagnetic wave absorption properties were determined from the frequency dependence of the reflection losses. From the measured results, it was found that the electromagnetic wave absorption properties are influenced by the superconductor content of samples and the temperature. At a room temperature, the electromagnetic wave absorption increased with increasing the Bi (Pb)-2223 superconductor system content, which was due to the increase of the complex permittivity. At a liquid nitrogen temperature, the electromagnetic wave absorption decreased because the superconductor system showed superconductivity.抄録全体を表示PDF形式でダウンロード (987K) -
大槻 龍生, 大橋 憲太郎2005 年 52 巻 12 号 p. 928-931
発行日: 2005年
公開日: 2006/04/28
ジャーナル オープンアクセスEffects of CuCl2 or FeCl3 intercalation on resistivity were studied using three kinds of carbon fibers (Vapor-grown, PAN, and Pitch) as well as HOPG (Highly Oriented Pyrolytic Graphite) and exfoliated graphite sheet (Grafoil). The stage-1 Graphite Intercalation Compounds (GIC) was formed by intercalation of CuCl2 and FeCl3 into VGCF as well as into HOPG and Grafoil. Stage-3 GIC was only formed by CuCl2 intercalation into PANCF and PitchCF, but not by FeCl3 intercalation. It was found that CuCl2 is an easier intercalated, compared with FeCl3. The temperature dependence of resistivity after intercalation was changed from semiconducting to metallic for VGCF as well as for HOPG-c and Grafoil.抄録全体を表示PDF形式でダウンロード (424K) -
島村 清史, Encarnación G. Víllora, 村松 研一, 竹川 俊二, 北村 健二, 一ノ瀬 ...2005 年 52 巻 12 号 p. 932-936
発行日: 2005年
公開日: 2006/04/28
ジャーナル オープンアクセスThe growth characteristics and properties of large size SrAlF5 single crystals are described and compared with those of BaMgF4. SrAlF5 shows a higher grade of transparency and a larger nonlinear effective coefficient as well as uniaxial and ferroelectric nature, on contrast to the one order smaller nonlinear coefficient and biaxial character of BaMgF4. The Sellmeier and Cauchy coefficients are obtained fitting the measured ordinary and extraordinary refractive indices, and the grating period for the first order quasi-phase matching (QPM) is estimated as a function of the wavelength. The higher potential of SrAlF5 in comparison with BaMgF4 for the realization of all-solid-state lasers in the ultraviolet wavelength region by the QPM technique is pointed out.抄録全体を表示PDF形式でダウンロード (1113K)
- |<
- <
- 1
- >
- >|