巻号一覧
55 巻, 2 号
February
選択された号の論文の16件中1～16を表示しています
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研究
研究速報
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岡野 佑輔, 中村 寿樹, 伊納 義孝, 安藤 智公, 大橋 憲太郎原稿種別: 研究速報
2008 年 55 巻 2 号 p. 85-89
発行日: 2008年
公開日: 2008/10/08
ジャーナル オープンアクセスNearly single-phase samples of high-Tc superconductors of the Bi-2212 phase have been prepared using a domestic microwave oven. Since it is to be important for the preparation to control the temperature of the sample environment, the samples were placed into thermally insulated box whose inner surface is made by SiC. An industrial microwave (2.45 GHz) furnace was used with repeating the microwave radiation processes with intermediate grinding. The comparison among microstructures of the samples obtained by domestic and industrial microwave ovens as well as those of TSFZ single crystals and polycrystals by solid state method was reported.抄録全体を表示PDF形式でダウンロード (1062K)
研究
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Mikio Ito, Junji Sumiyoshi原稿種別: Paper
2007 年 55 巻 2 号 p. 90-95
発行日: 2007年
公開日: 2008/10/08
ジャーナル オープンアクセスNaxCo2O4 powders synthesized by citric acid complex (CAC) process were mechanically milled with Ag particles around 1μm in size and then pressurelessly sintered. Effects of the mechanical milling on microstructure and thermoelectric properties of a NaxCo2O4/Ag composite were investigated. Ag powder was finely dispersed in the NaxCo2O4/Ag mixed powder after mechanical milling. The NaxCo2O4/Ag sintered bodies showed the large crystallographic anisotropy as compared to the NaxCo2O4/Ag composite synthesized by the conventional CAC process. However, Ag particles were coarsened during sintering, and the NaxCo2O4/Ag composite polycrystal with dispersion of fine Ag grains could not be obtained. By Ag addition, the electrical resistivity was significantly reduced, but the thermal conductivity was increased because of the coarse Ag phase, resulting in the dimensionless figure of merit almost the same as, or smaller than, that of the sample without Ag.抄録全体を表示PDF形式でダウンロード (1694K) -
水内 潔, 井上 漢龍, 上利 泰幸, 森貞 好昭, 杉岡 正美, 伊丹 正郎, 川舟 功朗, 川原 正和, 巻野 勇喜雄原稿種別: 研究
2008 年 55 巻 2 号 p. 96-100
発行日: 2008年
公開日: 2008/10/08
ジャーナル オープンアクセスDiamond-particle-dispersed-aluminum (Al) matrix composites were fabricated in solid-liquid coexistent state by Spark Plasma Sintering (SPS) process from the mixture of diamond and pure Al powders and that of diamond and 5056-type Al-Mg alloy powders. The microstructures and thermal conductivities of the composites fabricated were examined. These composites were all well consolidated at 813K for 2.1ks in SPS process. No reaction at the interface between the diamond particle and the Al matrix was observed by scanning electron microscopy for the composites fabricated under the sintering conditions employed in the present study. The relative packing density of the diamond-Al composite fabricated was 97% or higher in a volume fraction range of diamond between 25 and 45.5%. Thermal conductivity of the diamond-Al composite containing 45.5 vol.% diamond reached 403W/mK, approximately 76% the theoretical thermal conductivity estimated using Maxwell-Euckenís equation.抄録全体を表示PDF形式でダウンロード (1494K) -
勝井 明憲, 高橋 祐介, 松下 裕亮原稿種別: 研究
2008 年 55 巻 2 号 p. 101-105
発行日: 2008年
公開日: 2008/10/08
ジャーナル オープンアクセスSingle-phase delafossite-type CuMxLa1-xO2 (M=Mg, Ba, Ca, Sr, Mg, Zn, Cd) was synthesized by means of the solid-state reaction of a stoichiometrically mixed powder of binary oxides at 1273 K, for 10 h in an argon flow, and their luminescent properties were investigated. Undoped CuLaO2 exhibited a weak yellow-green photoluminescence-emission band due to the Cu+ interconfiguration transition at room temperature. The effect of II-group element doping on the photoluminescent properties was classified into two types. CuSrxLa1-xO2, CuBaxLa1-xO2 and CuZnxLa1-xO2 (x≤0.01) exhibited the emission slightly shifted to the shorter-wavelength side than that of undoped CuLaO2 and a strong emission intensity, with increasing doping concentration. These emission behaviors in CuSrxLa1-xO2, CuBaxLa1-xO2 and CuCaxLa1-xO2 was considered to be due to the formation of new emission centers upon doping Sr, Ba and Ca, respectively. CuZnxLa1-xO2, CuCdxLa1-xO2 and CuMgxLa1-xO2 (x≤0.01) exhibited the emission similar to one due to the Cu+ interconfiguration transition in undoped CuLaO2 and a weaker emission intensity, with increasing doping.抄録全体を表示PDF形式でダウンロード (559K)
特集：最先端応用を目指した磁性材料
総報
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阿部 正紀原稿種別: 総報
2008 年 55 巻 2 号 p. 108
発行日: 2008年
公開日: 2008/10/08
ジャーナル オープンアクセスPDF形式でダウンロード (100K)
総説
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宮崎 照宣, 大兼 幹彦, 桜庭 裕弥, 渡邉 大輔, Resul Yilgin, 佐久間 昭正, 安藤 康夫, 久保田 均原稿種別: 総説
2008 年 55 巻 2 号 p. 109-115
発行日: 2008年
公開日: 2008/10/08
ジャーナル オープンアクセスHistory about the research of magnetoresistance effect was reviewed. Also, we looked back on the research trends in the past when both giant magnetoresistance of Fe/Cr multi layered films and large tunnel magnetoresistance at room temperature were found.
Special emphasis was placed on the recent developments of huge TMR ratio for both MgO barrier tunnel junctions and Heusler alloy electrode tunnel junctions which contribute further to the development of spinelectronic research fields. Principle and importance of spin-transfer torque were also explained.抄録全体を表示PDF形式でダウンロード (1038K)
研究
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大森 秀人, 羽鳥 友哉, 中川 茂樹原稿種別: 研究
2008 年 55 巻 2 号 p. 116-120
発行日: 2008年
公開日: 2008/10/08
ジャーナル オープンアクセスRare-earth-transition metal (RE-TM) alloy films, such as TbFeCo and GdFeCo layers were used as perpendicularly magnetized layers for pinned and free layers in a perpendicular magnetic tunneling junction (p-MTJ). (100) oriented MgO tunneling barrier layer can be deposited on (100) oriented Fe (and FeCo) buffer layers. The (100) texture of the Fe (and FeCo) layers were enhanced by depositing them on the RE-TM layers. X-ray diffraction study clarified that MgO layers deposited on the Fe (and FeCo) layers revealed apparent (100) orientation at the early stage of the film growth. 3nm-thick MgO layer deposited on GdFeCo(100nm)/Fe(3nm) exhibited (100) texture.抄録全体を表示PDF形式でダウンロード (1087K) -
池本 潤一, 中川 茂樹原稿種別: 研究
2008 年 55 巻 2 号 p. 121-126
発行日: 2008年
公開日: 2008/10/08
ジャーナル オープンアクセスPt(3nm)/Fe(3nm) bilayered films deposited directly on glass disk substrates at room temperature exhibited preferential (100) orientation in Pt as well as Fe layers because of a hetero epitaxial growth from the bottom Fe(100) to the top Pt(100) textures. Highly ordered fct-FePt(001) alloy texture was appeared in the bi-layered film after annealed at 600°C in hydrogen atmosphere. Increase of substrate temperature up to 600°C during the deposition of 3nm-thick Pt layer on the Fe layer brought about a direct fabrication of fct-FePt(001) ordered alloy thin film.抄録全体を表示PDF形式でダウンロード (744K) -
松鵜 利光, 橋本 篤人, 中川 茂樹原稿種別: 研究
2008 年 55 巻 2 号 p. 127-131
発行日: 2008年
公開日: 2008/10/08
ジャーナル オープンアクセスRecently the development of the magnetic devices has been expected in the high frequency applications. The soft magnetic films with large saturation magnetization and high anisotropy field Hk have been required. In this study, FeCoB/NiFe/Si thin films deposited by Facing Targets Sputtering (FTS) system have saturation magnetization of 2 T and Hk of 20 kA/m, and exhibited high ferromagnetic resonance (FMR) frequency of 6.0-7.0 GHz in permeability characteristics. For improvement of high frequency permeability characteristics, we reduced the thickness of FeCoB soft magnetic layer. The results showed that damping constant was reduced and exhibited smaller loss capability. When changing of the FeCoB thickness, we investigated the change of anisotropy field Hk and FeCoB(110) lattice spacing in the perpendicular direction, which indicated that there was correlation between each other. From this relationship, we examined the origin of anisotropy field Hk.抄録全体を表示PDF形式でダウンロード (804K) -
白木 宏, 齊藤 高志, 山田 高広, 辻本 将彦, 東 正樹, 倉田 博基, 磯田 正二, 高野 幹夫, 島川 祐一原稿種別: 研究
2008 年 55 巻 2 号 p. 132-136
発行日: 2008年
公開日: 2008/10/08
ジャーナル オープンアクセスWe succeeded in synthesizing A-site ordered perovskites, CaCu3Ge4O12 and CaCu3Sn4O12, under high pressure and high temperature conditions. The magnetic measurements revealed that these compounds are ferromagnets in contrast to the isostructural antiferromagnet, CaCu3Ti4O12. The ferromagnetism in CaCu3Ge4O12 and CaCu3Sn4O12 comes from the special alignment of CuO4 planes in the perovskite structure. On the other hand, the involvement of Ti-3d orbitals in magnetic interactions give rise to the antiferromagnetic superexchange interaction and it overcomes the ferromagnetic direct interaction in CaCu3Ti4O12. The finding demonstrates that either ferromagnetic or antiferromagnetic behavior can appear within the same structural framework.抄録全体を表示PDF形式でダウンロード (673K) -
西村 浩輔, 東 正樹, 高野 幹夫, 島川 祐一原稿種別: 研究
2008 年 55 巻 2 号 p. 137-140
発行日: 2008年
公開日: 2008/10/08
ジャーナル オープンアクセスA double perovskite Pb2FeReO6 was prepared at a high pressure (6 GPa) and high temperature (1000°C) condition. The crystal structure determined by the synchrotron X-ray powder diffraction study was centrosymmetric with the space group I4/m despite the presence of Pb2+ ion in the A site. No structural transition to the lower symmetry was observe down to 23 K. This compound exhibited a ferrimagnetic transition at 420 K. The saturation magnetization varied with the degree of Fe3+/Re5+ ordering.抄録全体を表示PDF形式でダウンロード (443K)
新技術・新製品
新技術・新製品
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王 新敏, 井上 明久, 木村 久道原稿種別: 新技術・新製品
2008 年 55 巻 2 号 p. 143-145
発行日: 2008年
公開日: 2008/10/08
ジャーナル オープンアクセスPDF形式でダウンロード (690K) -
水嶋 隆夫, 小柴 寿人, 内藤 豊, 井上 明久原稿種別: 新技術・新製品
2008 年 55 巻 2 号 p. 146-148
発行日: 2008年
公開日: 2008/10/08
ジャーナル オープンアクセスPDF形式でダウンロード (512K) -
島田 良幸, 松沼 健二, 前田 徹, 西岡 隆夫, 池ヶ谷 明彦原稿種別: 新技術・新製品
2008 年 55 巻 2 号 p. 149-151
発行日: 2008年
公開日: 2008/10/08
ジャーナル オープンアクセスPDF形式でダウンロード (407K) -
小池 広樹, 梅村 崇, 船水 健司, 木下 聡原稿種別: 新技術・新製品
2008 年 55 巻 2 号 p. 152-154
発行日: 2008年
公開日: 2008/10/08
ジャーナル オープンアクセスIt is increasing in the importance of the highly efficient processing of high speed or high feed rate cutting as the means of the cost reduction and the environmental protection. Ti(C, N) based cermet indicates high wear resistance as low reactivity with steel. High efficiency cutting of Ti(C, N) based cermet is important to improved plastic deformation at high temperature. It's indicated microstructure of Ti(C, N) based cermet depend on grain size of powder, plastic deformation resistance of Ti(C, N) based cermet increasing with increase amount of WC in a series of studies. Super fine cermet GT/NS700 series is developed based this research for long tool life and stable high speeds cutting.抄録全体を表示PDF形式でダウンロード (1076K) -
伊達 賢治, 立川 清, 田中 茂徳, 池田 克巳原稿種別: 新技術・新製品
2008 年 55 巻 2 号 p. 155-157
発行日: 2008年
公開日: 2008/10/08
ジャーナル オープンアクセスPDF形式でダウンロード (678K)
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