巻号一覧
36 巻, 5 号
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坂東 尚周1989 年 36 巻 5 号 p. 458
発行日: 1989/07/25
公開日: 2009/05/22
ジャーナル フリーPDF形式でダウンロード (60K) -
永田 邦裕, 岩井 孝彦, 難波 典之1989 年 36 巻 5 号 p. 459-463
発行日: 1989/07/25
公開日: 2009/12/04
ジャーナル フリーBi-Sr-Ca-Cu-O system superconducting ceramics with the addition of various oxides such as PbO and Ag2O was prepared using ordinary sintering method and the degradation in moisture was discussed. The sample with the addition of 6-8 wt% of PbO showed superconductivity at 105 K. When the sample with the addition of PbO was aged at 95°C and 100% of humidity, the resistivity scarcely changed after aging until 2 hrs and it showed superconductivity at 105 K.抄録全体を表示PDF形式でダウンロード (265K) -
権 五興, 山田 興治, 平塚 信之, 杉本 光男1989 年 36 巻 5 号 p. 464-467
発行日: 1989/07/25
公開日: 2010/07/12
ジャーナル フリーTc and phases with Bi-Sr-Ca-Cu-O system were investigated in the substitution of transition elements (IVa, Va and VIa group) and non-trasition elements (IVb and Vb group) for Bi ions. These results are as follows. (1) The high Tc phase disappeared and low Tc phase increased in the substitution of transition elements for Bi ions. (2) The high Tc phase decreased in the substitution of Si and Sn (semiconductor element, IVb group) for Bi ions. (3) The high Tc phase increased in the substitution of Sb, As and P which were the same group of Bi for Bi ions. The substitution of P ions was the most effective and then the high Tc phase was formed in large quantity by replacing Bi ions with 30% of P ions.抄録全体を表示PDF形式でダウンロード (238K) -
西田 俊彦, 塩野 剛司, 大塚 隆, 西川 友三1989 年 36 巻 5 号 p. 468-473
発行日: 1989/07/25
公開日: 2009/05/22
ジャーナル フリーBi2Sr2CaCu2Ox polycrystalline ceramics or the ceramics powder prepared by solid-state reaction was cupsulated in copper can with the dimensions of 22φ-14φ-65 ?? . The billet (can containing ceramics) preheated at a temparature of 840°C for 8 minutes, and then successfully extruded by pressing at a maximum load of about 34 ton. Phase stability, texturing of ceramics before and after the processing, and effect of the processing on the densification of extruded polycrystal were investigated in this reserch.抄録全体を表示PDF形式でダウンロード (3056K) -
大橋 憲太郎, 高井 敏彦, 冨尾 重寿, 中 重治, 伊藤 秀章, 北口 仁, 小田 喜一, 高田 潤, 三浦 嘉也, 池田 靖訓, 高野 ...1989 年 36 巻 5 号 p. 474-477
発行日: 1989/07/25
公開日: 2009/05/22
ジャーナル フリーSpecimens of M2.2Sr2.0Ca2.0Cu3.zOy [M2.2=Bi1.8Pb0.4-x Inx and Bi1.8Pb0.2M'0.2 (M'=Sn, Sb and Y)] were sintered at 855°C for 40-96hr after decarbonation in air atomosphere and their resistance-temperature curves were compared in order to investigate effects of "inert pair" elements on the formation of the high-Tc phase. In low level of In content (x-value) below 0.18, the stabilization of the high-Tc phase by incorporation of Pb remained almost unaffected. The step wise (shoulder-like) drop in resistance curves due to the coexistence of high and low- Tc phases was observed on specimens of In0.2, Sn0.2 and Sb0.2, showing that lighter inert pair elements have poorer tendency to stabilize the high-Tc phase. The specimen of Y0.2 showed disappearance of the high-Tc phase as well as in specimens of In0.4 without Pb.抄録全体を表示PDF形式でダウンロード (222K) -
永井 宏, 横田 勝, 真島 一彦, 喜多 善史, 大林 健, 覚前 正博1989 年 36 巻 5 号 p. 478-481
発行日: 1989/07/25
公開日: 2009/05/22
ジャーナル フリーThe high temperature behaviors of Bi-Sr-Ca-Cu-O and Bi(Pb)-Sr-Ca-Cu-O superconductors were investigated by electrical resistivity measurement and X-ray diffraction in relation to superconducting properties. (1) For BiSrCaCu2 Oy: Two peaks in the temperature dependence of the electrical resistivity were detected at 300 and 650°C on heating process, but no peak was detected on cooling process. (2) For Bi0.7 Pb0.3 SrCaCu1.8 Oy: Two peaks were also detected at 300 and 650°C for the samples with Low-Tc phase, but they decreased with increasing content of High-Tc phase in the samples and finally disappeared for the samples with almost High-Tc single phase. (3) For Bi2 Sr2 CaCu2 Oy: The peaks detected in the electrical resistivity on heating process became more apparent than those of the other samples described above. From these results, it may be concluded that the peaks in the electrical resistivity detected at 300 and 650°C are due to the Low-Tc phase, High temperature X-ray diffraction showed that no change was observed at 300°C, but Low-Tc phase seemed to decompose at 650°C. Further detailed research is in progress.抄録全体を表示PDF形式でダウンロード (202K) -
宮本 大樹, 宮本 敬, 稲村 偉, 高橋 弓弦1989 年 36 巻 5 号 p. 482-484
発行日: 1989/07/25
公開日: 2009/05/22
ジャーナル フリーThe content of high Tc phase Bi2Sr2Ca2Cu3Ox in the sintered specimen increased remarkably when a small amount of powder of 2223 phase was added to the starting powder as seeds. The 2223 phase was of more than 90% when sintered at 860°C for 150h with 10 wt% of 2223 powder added. A small amount of impurity phases such as Ca2CuO3 was selectively dissolved in water. Powder of 2223 phase without other phases was obtained.抄録全体を表示PDF形式でダウンロード (1266K) -
宮本 大樹, 宮本 敬, 稲村 偉, 高橋 弓弦1989 年 36 巻 5 号 p. 485-488
発行日: 1989/07/25
公開日: 2009/05/22
ジャーナル フリーHigh Tc phase with c=3.7 nm of Bi2Sr2Ca2Cu3Ox was synthesized from powder prepared by Sol-Gel method. The sol was prepared from strontium acetate, calcium acetate, copper acetate and bismuth ethoxide.
When powdering-sintering cycles were repeated four times with total sintering time of 148 h at 845°C-850°C, the amount of the high Tc phase in the specimen with starting composition ratio of 2:2:2.2:3.2, was larger than 95% from XRD measuerment. Tcoffset of the specimen was of 90K.
From the sol descrived above, gel fibers with a length of 1 m and a diameter of 100 μm to 300 μm were successfully drown. After sintering at 845°C for 5 h, ceramic fiber of which Tconset, was of 110K were obtained.抄録全体を表示PDF形式でダウンロード (1775K) -
松田 元秀, 高田 雅介, 山下 努, 石井 守, 鯉沼 秀臣1989 年 36 巻 5 号 p. 489-492
発行日: 1989/07/25
公開日: 2009/12/04
ジャーナル フリーThe effect of annealing, which was carried out at 300°C-845°C for 24h in air, on the superconductivity in the Bi-Pb-Sr-Ca-Cu-O ceramics was investigated. The tailing phenomenon was observed in the R-T curves for all samples annealed at temperatures in the range of 600°C to 825°C though the as-sintered sample and the samples annealed at 300°C, 400°C and 845°C exhibited a sharp superconducting transition above 100K. In addition, a relatively large unknown peak was observed at 2θ=17.9° close to the main peak(2θ=17.6°) of the Ca2PbO4 phase in the X-ray diffraction pattern of the sample annealed at 700°C. From the above results, it is supposed that the tailing phenomenon in the R-T curve is closely related to an appearance of the unknown peak.抄録全体を表示PDF形式でダウンロード (170K) -
岡 与志男, 山本 直一, 冨井 洋一, 北口 仁, 小田 喜一, 高田 潤1989 年 36 巻 5 号 p. 493-496
発行日: 1989/07/25
公開日: 2009/05/22
ジャーナル フリーAs a rule crystallization of amorphous Bi2Sr2CaCu2Oy leads to the 24A phase followed by the formation of the 30A phase above 800°C. The nominal composition of the 24A phase is Bi2Sr2CuOy and hence the crystallization into the 24A phase causes the problem of the discrepancy of composition. In order to solve the problem, crystallization process of fast-quenched Bi2Sr2CaCu2Oy has been examined by using the X-ray diffraction and SEM-EDX. It has been found that the crystallization of amorphous Bi2Sr2CaCu2Oy into the 24A phase was accompanied with the phase separation into the 244 phase and a Cu-rich region so as to adjust the compositions. In the next step of crystallization, the separated regions reacted together above 800°C into the 30A phase.抄録全体を表示PDF形式でダウンロード (1311K) -
貞広 嘉和1989 年 36 巻 5 号 p. 497-500
発行日: 1989/07/25
公開日: 2009/05/22
ジャーナル フリーThe mixture of Y2O3, BaCO3 and CuO was ground by a vibration mill with allumina vessel.The products were calcined at 925°C for 2 days, and annealed at 500°C for several days. The effects of dry grinding on the samples were inferred from the variations of the strain (<ε I.2>1/2 ) and the lattice parameters (a, bc) determined by X-ray diffraction.
As the results, it has been clarified that the grinding for 100 minutes under above mentioned heating conditions gives the best conductor of these products.抄録全体を表示PDF形式でダウンロード (197K) -
増田 喜男, 建石 剛1989 年 36 巻 5 号 p. 501-505
発行日: 1989/07/25
公開日: 2009/12/04
ジャーナル フリーDependence of residual carbons in YBa2Cu3Ox powders prepared through sol⋅gel method on the heating conditions and their effects on superconducting properties of the powders were studied. Carbons were left 2.4-0.02wt% in the powders calcined at the various heating conditions that the holding temperatures were 600°C to 950°C and the flow gases were pure oxygen and air. The carbon content of the powders prepared through sol⋅gel method could be lower than that of the powders prepared by solid state reaction of powders of the mixed oxides. From the result of XPS and FT-IR analysis it was found that the residual car-bon existed as the state of carbonates and concentrated at the surface of the powders.
The powders whose carbon contents were lower than 0.4wt% could show superconducting transition. Magnetic susceptibitities and Tc(onset) of these powders were improved in proportion to decrease of the carbon contents, but Tc(onset) properties could not keep on growing up, being less than 0.04wt% of carbon contents.抄録全体を表示PDF形式でダウンロード (1532K) -
戸叶 一正1989 年 36 巻 5 号 p. 506-509
発行日: 1989/07/25
公開日: 2009/05/22
ジャーナル フリーThe critical current densities of the oxide high-TC superconductors obtained so far are not sufficient for practical application. In addition to the strong anisotropy in superconducting properties, there are several factors that determine the JC of the oxide superconductors, which are weak link at grain boundaries, flux pinning mechanism, and flux creep. In this review paper, our recent results for intergrain coupling and flux creep in Bi- and Tl-based materials are presented. The grain alignment in Bi-Pb-Sr-Ca-Cu-O material, which can be achieved by tape processing techniques, has been found to improve the intergrain coupling and also the flux creep problem. The resistivity vs. temperature curves in magnetic fields measured for Tl-Ba-Ca-Cu-O single crystal indicates an exponential temperature dependence of the resistivity at lower resistivity region, suggesting that the resistivity occurrence is due to the thermally activated flux motion.抄録全体を表示PDF形式でダウンロード (220K) -
横田 勝, 永井 宏, 真島 一彦, 神原 光一1989 年 36 巻 5 号 p. 510-513
発行日: 1989/07/25
公開日: 2009/05/22
ジャーナル フリーPossibility of grain orientation controlling by thermal diffusion treatment at various temperature gradient was studied for the superconductive YBa2Cu3Oy ceramics by means of X-ray diffraction analysis and SEM observations: The degree of orientation estimated by X-ray diffraction analysis was unexpectedly low, but local structures in SEM images was observed to be fairly oriented along heat flow derections. For obtaining highly oriented structures, one-directional temperature gradient during sintering should be elevated as possible.抄録全体を表示PDF形式でダウンロード (2590K) -
真島 一彦, 永井 宏, 横田 勝, 大林 健, 友沢 淳1989 年 36 巻 5 号 p. 514-517
発行日: 1989/07/25
公開日: 2009/05/22
ジャーナル フリーBy using six different kinds of Bi0.7 Pb0.3 Sr1.0 Ca1.0 Cu1.8 Oy powders named A-E whose particle size is smaller in the sequence B-A-D-C(30)-C(60)-E and one kind of Bi1.8 Pb0.3 Sr1.9 Ca2.0 Cu3.0 Oy powder named F whose particle size is almost similar to that of B powder, the influence of particle size on the amount of high Tc phase or superconductive property has been investigated.
Whereas the formation of high Tc phase in Bi0.7 Pb0.3 Sr1.0 Ca1.0 Cu1.8 Oy specimen was accelerated by using the smaller particle size powder, any remarkable relationship be-tween superconductive property and particle size was not observed. On the other hand, the Bi1.8 Pb0.3 Sr1.9 Ca2.0 Cu3.0 Oy specimen showed both of high volume fraction of high Tc phase and the improved superconductive property.
The sintered density of the Bi0.7 Pb0.3 Sr1.0. Ca1.0 Cu1.8 Oy specimen once increaced in the shorter sintering period than 24h, and decreased in the longer sintering period. However the Bi1.8Pb0.3 Sr1.9 Ca2.0 Cu3.0 Oy specimen showed only decreasing tendency of sintered density even in the shorter sintering period.抄録全体を表示PDF形式でダウンロード (2342K) -
真岩 宏司, 一ノ瀬 昇1989 年 36 巻 5 号 p. 518-522
発行日: 1989/07/25
公開日: 2009/12/04
ジャーナル フリーThick films in the Bi-Pb-Sr-Ca-Cu-O system have been synthesized using a fine particle size powder milled with 2mmφ zirconia balls. Films prepared on the single crystal MgO substrates show strongly textured orientation with c axis of the 37A phase and the 30A phase. Bi1.95Pb0.6Sr2Ca2.2Cu3.5Oz film sintered at 835°C for 20h in a Pot of 1/11atm showed Tc(R=0)=107.1K, and Jc(77K, zero magnetic field)=33A/cm2.抄録全体を表示PDF形式でダウンロード (2954K) -
堀田 勝喜, 鈴木 敏正, 廣瀬 治男, 小池 吉広1989 年 36 巻 5 号 p. 523-526
発行日: 1989/07/25
公開日: 2009/05/22
ジャーナル フリーGenerally bad effects of water on the superconductivity of high Tc superconductors have been pointed out by many workers. Present paper deals with the observation of the deterioration process of Bi-Pb-Sr Ca- Cu-O system soaked in water.
The resistivity vs temperature curves clearly showed the deterioration (lowering of Tc) of the samples soaked in water. The investigation of magnetic properties is also given with respect to the water effect.抄録全体を表示PDF形式でダウンロード (1306K) -
高田 潤, 小田 喜一, 江木 俊雄, 北口 仁, 尾坂 明義, 三浦 嘉也, 池田 靖訓, 高野 幹夫, 冨井 洋一, 岡 与志男, 山本 ...1989 年 36 巻 5 号 p. 527-532
発行日: 1989/07/25
公開日: 2009/12/04
ジャーナル フリーThe influence of the sintering time on the formation of high-Tc phase and the electrical property has been studied for the sample with a nominal composition of Bi:Pb:Sr:Ca:Cu=0.96:0.24:1.0:1.1:1.6. The volume ratio of the high-Tc phase to the superconductive phases was approximately 85% by the heat treatment at 850°C for 48h, while the almost single high-Tc phase was obtained by repeating sintering procedures. The high-Tc phase particles were grown up to be about l0um in width for 48h, and after then the particle size remained almost constant. This tendency corresponds to the change in the volume ratio of the high-Tc phase on the heat treatment. As sintering time extended, Pb content decreased. The sample heat treated at 850°C for 200h had only 6% of its initial Pb content. The electrical resistance dropped to zero at 110K within the experimental limit of 10-6 ohm in the sample heat treated at 850°C for 150h in air. However, the samples heat treated for 200h or more showed tailing in R-T curves.抄録全体を表示PDF形式でダウンロード (2314K) -
高田 潤, 北口 仁, 国屋 宏明, 佐藤 幸治, 小田 喜一, 尾坂 明義, 三浦 嘉也, 池田 靖訓, 高野 幹夫, 坂東 尚周, 菅野 ...1989 年 36 巻 5 号 p. 533-541
発行日: 1989/07/25
公開日: 2009/12/04
ジャーナル フリーEquilibrium phase relationships for the pseudo-ternary systems PbO-CaO-CuO, PbO-SrO-CuO and PbO-CuO-SrO have been studied mainly by the X-ray diffraction method. The equilibrium phase diagram of the PbO-CaO-CuO system was drawn up at 700°C, 800°C and 850°C in air. The equilibrium phase diagram of the PbO-SrO-CuO system was determined at 700°C and 800°C in air. A part of phase diagram of the PbO-CaO-SrO system was drawn up at 800°C in air. At 800°C and 850°C, the regions of liquid or liquid+solids were determined in each systems. In the PbO-SrO-CuO system we found a new ternary solid solution. In the PbO-CaO-SrO system we found that (Ca1-xSrx2)2PbO4 was a solid solution of 0≤x≤1.0 at 800°C. The composition dependences of lattice parameters and decomposition point of a solid solution (CaxSr2)PbO4 were determined.抄録全体を表示PDF形式でダウンロード (347K) -
小嶌 信貴, 上田 寛, 吉村 一良, 小菅 皓二1989 年 36 巻 5 号 p. 542-545
発行日: 1989/07/25
公開日: 2009/05/22
ジャーナル フリーThe samples of (CaxY1-x)(LaxBa2-x)Cu3Oy were prepared by firing at 900-950°C in flowing O2 gas. The X-ray diffraction pattern showed that the sample was solved in a single phase of orthorohombic structure with x=0-0.3 and of tetragonal structure with x=0.4-1.0. All the samples showed superconducting transitions between 70K and 95K on both electrical resistivity and magnetic susceptibility. A sharp superconducting transition with ΔT=2K was observed at 80K in the sample with x=1.0, i.e., CaLaBaCu3Oy. In the intermediated composition range, the samples showed broad superconducting transitions with two step drops of resistivity at about 80K and 90K, implying the coexistence of 80K- and 90K-class superconducting phases with a microscopic scales of textures.抄録全体を表示PDF形式でダウンロード (180K) -
勝山 茂, 上田 寛, 小菅 皓二1989 年 36 巻 5 号 p. 546-550
発行日: 1989/07/25
公開日: 2009/05/22
ジャーナル フリーThe crystal structure and superconducting properties of YBa2(Cu1-xFex)3Oy prepared by various heat treatments were examined by X-ray powder diffraction, electrical resistivity, ac susceptibility and57Fe Mössbauer effect measurements. The orthorhombic phases were obtained up to x=0.02, 0.04 and 0.12 by the heat treatments of (a)slow cooling from 850°C in O2 gas, (b)quenching into liq. N2 from 930°C in air followed by oxidation below 400°C in O2 gas and (c)heating at 800°C in N2 gas followed by oxidation below 400°C in O2 gas, respectively. The differences of the orthorhombic region and Tc among the samples prepared by the heat treatments (a), (b) and (c) were explained by the distribution of Fe ions intra- and inter-(Cu-O)planes.抄録全体を表示PDF形式でダウンロード (299K) -
川口 建二, 秋葉 悦男, 新 重光, 東嶋 成秋1989 年 36 巻 5 号 p. 551-554
発行日: 1989/07/25
公開日: 2009/05/22
ジャーナル フリーThe system (Li1-xMx)Ti2O4 (M=Mg, Be) with the spinel structure was prepared by firing twice a mixture of the component oxides, i.e., Li2O, MgO, BeO, Ti2O3, and Ti02 at 1073K for 12 h in vacuo(ca. 10-5 Torr). The lattice constants were obtained by the powder X-ray diffractometry whereas the molar fraction of Ti3+ ions in the total Ti atoms, i.e., f (%) was determined by thermogravimetry. The critical temperatute Tc(K, mid-point) was obtained by using a usual four-probe resistivity measurement in the range of 300 K to ca. 2 K. As a result, the cubic lattice constant a(A) of the system linearly increased as the molar ratio f increased. However, it was found that Be2+ with a much smaller ionic radius than that of Li+ can hardly replace the Li+ site of the spinel structure, as implied from the plots of the lattice parameter a and the chemical composition x. The highest Tc was observed at f=ca. 50 % in the composition Li1+xXTi2-xO4, and the Tc suddenly decreased as either the molar ratio f or the lattice constant a decreased. On the other hand, the Tc of the composition (Li1-xMgx)Ti2O4 gradually decreased as either the molar ratio f or lattice constant a increased.抄録全体を表示PDF形式でダウンロード (174K) -
武田 保雄, 菅野 了次, 坂野 正明, 山本 治, 高野 幹夫1989 年 36 巻 5 号 p. 555-558
発行日: 1989/07/25
公開日: 2009/12/04
ジャーナル フリーStructural and electrical properties of the system crystallizing in K2NiF4 structure, La2-xSrxNiO4(O≤x≤1.6) were studied. Powder x-ray diffraction data were analyzed by the Rietveld method to determine the bond lengths. Tetragonality in the lattice parameters, c/a, shows a maximum at x=0.6, while, distortion of a NiO6 octahedron, Ni-0(2)(//c-axis)/ Ni-O(1)(//a-axis), monotonously decreases from 1.17(x=0) to 1.03(x=1.4). A metal-semiconductor transition in observed for O<x<l.2, the transition temperature decreasing from 690K(x=0) to 20K(x=1.2). For x≥1.3, the specimen show metallic behavior down to 10K.抄録全体を表示PDF形式でダウンロード (181K) -
吉川 雅章, 上田 寛, 吉村 一良, 小菅 皓二1989 年 36 巻 5 号 p. 559-563
発行日: 1989/07/25
公開日: 2009/05/22
ジャーナル フリーA ceramic sample of Pb2Sr2Y0.5Ca0.5Cu3Oy containing no impurity phases was prepared by reacting PbO and Sr-Y-Ca-Cu-0 precursor in a flowing nitrogen gas at 750-C. Powder X-ray diffraction pattern shows that it has an orthorhombic structure with lattice parameters a=0.537nm, b=0.542nm and c=1.576nm. The samples which have various oxygen contents(y) ranging from 8 up to neary 10 were prepared by oxidation of this material. The relation between oxygen contents and superconducting properties was investigated by electrical resistivity measurement using a DC four-probe technique. The sharpest superconducting transition among these samples was observed on a slightly oxidized material. The samples with large oxygen content which have tetragonal structure show semiconducting behavior.抄録全体を表示PDF形式でダウンロード (227K) -
池田 靖訓, 下村 真一, 伊藤 浩之, 広井 善二, 高野 幹夫, 坂東 尚周1989 年 36 巻 5 号 p. 564-570
発行日: 1989/07/25
公開日: 2009/12/04
ジャーナル フリーYasunori Ikeda, Shinichi Shimomura, Hiroyuki Ito, Zenji Hiroi, Nikio Takano and Yoshichika Bando: The subsolidus phase diagram of the BiO1.5-SrO-CuO system at 840°C in air. Solid phases and thier relations in the BiO1.5-SrO-CuO system were investigated at 840 C in air. Bi2+xSr2-xCu1+vOz (0.1<x<0.6, 0<y<x/2), Bi17Sr16Cu7Oz, Bi2Sr3Cu2Oz and BiSr3Oz, have newly been found. Structural data was obtained by means of powder XRD and TEN. The superconductor with a Tc-10K corresponds to the Bi-poorest end of the solid solution mentioned above.抄録全体を表示PDF形式でダウンロード (925K) -
澤 博, 小原 和彦, 秋光 純1989 年 36 巻 5 号 p. 571-574
発行日: 1989/07/25
公開日: 2009/05/22
ジャーナル フリーA new family of high-TC superconductors (Ln1-xCex)2(Ba1-yLny)2Cu3O10-z (Ln : Nd, Sm, Eu, Gd) has been found by resistivity and magnetization measurements. The highest onset transition temperature is about 48K. The structure is proposed on the basis of electron diffractions and Rietveld analysis of powder X-ray diffraction data.抄録全体を表示PDF形式でダウンロード (234K) -
大谷 槻男1989 年 36 巻 5 号 p. 575-578
発行日: 1989/07/25
公開日: 2009/05/22
ジャーナル フリーSeebeck coefficients (S) of LnBa2Cu3O7-y(Ln=Sm, Eu, Dy, Ho, Er and Yb) and a nearly single phase Ca-substituted LuBa2Cu3O7-y show the similar temperature dependences as S of YBCO, but have a tendency of decreasing of S values with increasing the atomic number of lanthanides; Ho-, Er-, Yb- and Lu-oxides show the negative S below 550 °C, implying that the dominant carriers are electrons. S of high Tc phase of bismates (2223 phase) is negative in a range 200-850 °C, which may also indicate the electron conduction.抄録全体を表示PDF形式でダウンロード (165K) -
森山 斉昭, 吉川 信一, 高橋 昌男, 延谷 宏治, 金丸 文一1989 年 36 巻 5 号 p. 579-583
発行日: 1989/07/25
公開日: 2009/12/04
ジャーナル フリーMicro structures and electrical properties were investigated on thin films crystallized from amorphous Y-Ba-Cu-O film prepared by rf-sputtering. Effects of fluorine or CuO addition to the amorphous film were also studied on these properties. An elevation of crystallization temperature enhanced both platy YBCO crystal growth and its orthorhombic c-axis preferred orientation in the crystallized film on MgO substrate. Sputtering power was more important on the film / SrTiO3. No preferred orientation was observed on the film prepared at 100W power. Larger rf-power and fluorine addition to sputter target elevated substrate temperature (Ts). Epitaxially preferred oriented films were obtained at Ts≥350°C. Amorphous films containing fluorine or excess CuO gave c-axis preferred orientations at annealing temperature of 50°C lower than that of Y-Ba-Cu-O film. CuO added film showed the best result on superconducting transition (Tc zero≥70 K) in the present investigations.抄録全体を表示PDF形式でダウンロード (4222K) -
村上 雅人1989 年 36 巻 5 号 p. 584-587
発行日: 1989/07/25
公開日: 2009/05/22
ジャーナル フリーYBa2Cu3Ox powders were rapidly heated to the Y2O3 plus liquid region and quenched using copper hammers. The quenched plates were again heated to the Y2BaCuO5 plus liquid region and slow cooled in a thermal gradient. The process enabled uni-directional growth of the superconducting phase. Magnetization measurements revealed that magnetic properties of the melt processed samples could be understood in terms of Bean critical state model. The samples attained Jc values exceeding 104 A/cm2 at 77K and 1T. Ginat flux creep was not observed in such samples.抄録全体を表示PDF形式でダウンロード (1170K) -
藤原 康文, 平田 智嗣, 井寄 将博, 小林 猛1989 年 36 巻 5 号 p. 588-591
発行日: 1989/07/25
公開日: 2009/05/22
ジャーナル フリーCathodeluminescence (CL) from high TC superconducting hulk ceramics (Y-Ba-Cu-O. Bi-Sr-Ca-Cu-O and TI-Ba-Ca-CU-O systems) and thin films (Y- and Bi-systems) has been system-atically investigated by using a modified scanning electron microscope (SEM). Characteristic CL has been successfully observed in all bulk ceramics. With particular emphasis on the TI-system. the CL results are demonstrated. The CL pattern reveals a nonuniformity. not due to the roughness of the sample surface. The CL spectrum consists of two broad bands located in the visible region. The temperature dependence of the CL spectrum has been measured. In the thin films, the luminescence is dominated by the well-known blue emission from the MgO substrate excited through the film. the analysis suggesting a feasibility of the interface characterization by CL measurements.抄録全体を表示PDF形式でダウンロード (2032K) -
寺嶋 孝仁, 坂東 尚周, 飯島 賢二, 山本 和貫, 平田 和人1989 年 36 巻 5 号 p. 592-596
発行日: 1989/07/25
公開日: 2009/05/22
ジャーナル フリーEpitaxial growth of (001) oriented YBa2Cu3O7-x(YBCO) on SrTiO3(100) and MgO(100) by activated reactive evaporation was investigated by insitu reflection high energy electron diffraction (RHEED). RHEED observation of the YBCO films on both the substrates demonstrated the formation of the perovskite structure even at initial deposit. A sharp streak in every deposition stage revealed the layer-by-layer growth. The initial deposit on the substrate of MgO with the large mismatch of 9% kept the same in-plane lattice spacing as MgO. The lattice spacing converted from the bulk value of Mg0 to that of YBCO when the layer became thicker than 12Å.抄録全体を表示PDF形式でダウンロード (2981K) -
間崎 啓匡, 安岡 宏, 山本 和貫, 平田 和人, 飯島 賢二, 寺島 孝仁, 坂東 尚周1989 年 36 巻 5 号 p. 597-600
発行日: 1989/07/25
公開日: 2009/05/22
ジャーナル フリーSuperconducting transions of single-crystal YBa2Cu3O7-x, thin films (100-6000 Å) and bulk specimen (1×1×0.5 mm3), were investigated in terms of complex susceptibility. Thin films measured in a magnetic field perpendicular to the film plane exhibited a characteristic field-amplitude dependence, i.e., for higher amplitude, the transition curve shifts to lower temperatures. The bulk specimen showed different features for a magnetic field parallel and perpendicular to the c planes. Some qualitative discussion is given.抄録全体を表示PDF形式でダウンロード (190K) -
山本 和貫, 平田 和人, 飯島 賢二, 間崎 啓匡, 寺嶋 孝仁, 坂東 尚周1989 年 36 巻 5 号 p. 601-604
発行日: 1989/07/25
公開日: 2009/12/04
ジャーナル フリーHigher harmonics of complex susceptibility were measured for single-crystal YBa2Cu3O7-x, bulk specimen and thin films. For the bulk specimen, any higher harmonics were not observed. This result is consistent with the Maxwell and Strongin model. In contrast with this, for the thin film specimen placed in transverse magnetic field, third harmonics have a finite value in the transition region. This suggests the existence of nonlinear flux motion going into and out of the specimen.抄録全体を表示PDF形式でダウンロード (253K) -
海江田 義也, 和田 仁, 伊藤 喜久男, 黒田 恒生, 小田原 修1989 年 36 巻 5 号 p. 607-610
発行日: 1989/07/25
公開日: 2009/05/22
ジャーナル フリーThe effect of binding additives on superconductivity is studied in Y-Ba-Cu-O ceramics. Mixtures of Y2O3, Ba(NO3)2 and CuO ( 1:2:3 ) are calcined, and sintered with the 10 mol% binding additives of the each component, respectively. The critical temperature and the zero field critical current density are measured. The values of Tc of the specimens are almost same but the values of Jc are sensitive to the kinds of binding additives. When sintered at 1193 K, Jc of the specimen with CuO additives is 218 A/cm2, and 7 A/cm2 is that of the specimen with Ba(NO3)2 additives. It has been confirmed that 10mol% CuO should be a proper additive for increasing the Jc value in the Y-Ba-Cu-O system.抄録全体を表示PDF形式でダウンロード (232K) -
海江田 義也, 和田 仁, 伊藤 喜久男, 黒田 恒生, 小田原 修1989 年 36 巻 5 号 p. 611-614
発行日: 1989/07/25
公開日: 2009/12/04
ジャーナル フリーThe effect of cold isostatic pressing in the forming process on superconductivity is studied in Y-Ba-Cu-O system ceramics. Y2O3, Ba(NO3)2 and CuO are mixed to the ratio of Y:Ba:Cu=1:2:3, calcined at 1173 K, mixed with and without the various amount of CuO as a binding additive, formed with cold isostatic press at various pressure and sintered at 1173 K. The critical temperature and the zero field critical current density at 77 K are measured. The values of Tc are almost same in all kinds of the specimens but the values of Jc are sensitive to the amount of a binding additive and the cold isostatic forming pressure.抄録全体を表示PDF形式でダウンロード (238K) -
太田口 稔, 小黒 信高, 海江田 義也, 伊藤 圭二1989 年 36 巻 5 号 p. 615-619
発行日: 1989/07/25
公開日: 2009/12/04
ジャーナル フリーThe effects of the amount of Pb additive and the cooling rate after sintering are investigated to develop the fabrication technique of Bi system'superconductor. The temperature in which no specimen is softened, 844°C, is selected as a sintering temperature and the growth of the superconducting phase is investigated. The most favorable content of Pb is 0.2% from the results of the measurement of the magnetic susceptibility and X-ray diffraction and SEM observation. From the results of the experiments to investigate the effect of cooling rate after the sintering, specimen which has the most slow cooling rate, 0.4°C/min, has most high Tc phase.抄録全体を表示PDF形式でダウンロード (2874K) -
小黒 信高, 太田口 稔, 海江田 義也, 伊藤 圭二1989 年 36 巻 5 号 p. 620-623
発行日: 1989/07/25
公開日: 2009/05/22
ジャーナル フリーThe effect of the heat treating time is investigated to develop the fabrication technique of Bi system superconductor. A temperature just below the softening of the specimen is selected as a sintering temperature. The content of Pb additive is substituted for 20% of Bi. Various heating time and the growth of the superconducting phase are investigated. The measurements of the magnetic susceptibility, X-ray diffraction and SEM observation of the superconducting phase are carried out. From the results of the experiments to investigate the effect of heat treating time, the specimen with 300 hours of heat treatment time has most high Tc phase.抄録全体を表示PDF形式でダウンロード (3536K) -
海江田 義也, 小黒 信高, 太田口 稔, 伊藤 圭二1989 年 36 巻 5 号 p. 624-628
発行日: 1989/07/25
公開日: 2009/12/04
ジャーナル フリーThe effects of the number of times for the calcinations and of the cooling rate are investigated to develop the fabrication technique of Bi-system superconductor. A temperature just below the softening of the specimen is selected as a calcinating and a sintering temperature. The content of Pb additive is substituted for 20%of Bi. The measurements of the magnetic susceptibility, resistivity, critical temperature, critical current, X-ray diffraction and SEM observation of the superconducting phase are carried out. From the results of the experiments to investigate the effect of the conditions of the calcination and cooling rate, the specimen after a second calcination and 0.1°C /min cooling rate shows good superconductivity and the critical current density Jc=49A/cm2.抄録全体を表示PDF形式でダウンロード (1552K)
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