巻号一覧
41 巻, 12 号
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坂東 尚周1994 年 41 巻 12 号 p. 1452
発行日: 1994/12/15
公開日: 2009/05/22
ジャーナル フリーPDF形式でダウンロード (85K) -
高野 幹夫, 武田 保雄, 廣井 善二1994 年 41 巻 12 号 p. 1453-1458
発行日: 1994/12/15
公開日: 2009/05/22
ジャーナル フリーRecent progress in materials search for new high-Tc superconductors by using a high-pressure synthesis method is reviewed. Particularly through a series of studies exploring the alkaline earth copper oxide system it is demonstrated how the application of high pressure can affect the phase formation and thus can provide novel mate-rials with unusual structures or compositions.抄録全体を表示PDF形式でダウンロード (394K) -
鄂 剛, 吉川 信一, 高橋 昌男, 金丸 文一, 萩行 正憲, 木曽田 賢治, 中島 信一1994 年 41 巻 12 号 p. 1459-1463
発行日: 1994/12/15
公開日: 2009/05/22
ジャーナル フリーLocal structure of infinite layered superconductor Sr1-xLaxCuO2 in low temperature was investigated by EXAFS, X-ray diffraction and Raman spectroscopy. EXAFS showed that the Cu-O bond distance slightly expanded in a range <0.1Å with lowering temperature down to 20K.
The expansion was remarkable below Tc(onset)=43K. Tetragonal lattice parameters shrank with lowering temperature but the shrinkage of a-parameter seemed to be almost saturated below Tc(onset). Oxygen atoms may slightly shift their positions above and below the CuO2 plane. Raman spectrum of Sr1-xLaxCuO2 superconductors were Raman active although infinite layered structure should be Raman inactive from its symmetry. Resonance Raman peaks were observed at 151cm-1 and 304cm-1 in a usage of 4880Å Ar ion laser. Its energy of 2.54eV almost corresponds to that of the exitation between lower and upper Hubard bands. The peak intensities increased with lowering temperature even above Tc(onset). The intensity change may also be related to the change observed with both X-ray absorption and diffraction in local structure with temperature. The CuO2 plane may buckle as reported in atomic pair distribution function refinement of neutron diffraction data on (Nd.Ce)2CuO4 in low temperature.抄録全体を表示PDF形式でダウンロード (268K) -
東 正樹, 廣井 善二, 高野 幹夫, 北岡 良雄, 石田 憲二1994 年 41 巻 12 号 p. 1464-1468
発行日: 1994/12/15
公開日: 2009/05/22
ジャーナル フリーSrCu2O3 and Sr2Cu3O5 containing two-leg and three-leg S=1/2 ladders made of antiferromagnetic Cu-O-Cu linear bonds, respectively, were synthesized at high pressure, and their crystallographic and magnetic properties were investigated. Susceptibility of the 2-leg ladder system, SrCu2O3, showed a thermal excitation from the nonmagnetic ground state with a large spin gap of 420 K, while Sr2Cu3O5 containing 3-leg ladders had a finite susceptibility at the lowest temperature reflecting its gapless nature in the spin excitation spectrum. SrCu2O3 has thus been found to be the first 2-leg ladder compound having a well-defined spin gap.抄録全体を表示PDF形式でダウンロード (1438K) -
山浦 一成, 廣井 善二, 高野 幹夫1994 年 41 巻 12 号 p. 1469-1474
発行日: 1994/12/15
公開日: 2009/05/22
ジャーナル フリーA cupric oxide carbonate superconductor with a Tc of 92K has been synthesized under high pressure of 6GPa. A single phase sample with a large Meissner volume fraction of 20% is obtained when a mixture with a nominal composition (Ca0.3Sr0.7)3Cu2 C0.75 Oy encapsulated with an oxidizer of KClO4 is treated at 1473K and 6GPa for 30 minutes. The phase crystallizes basically in tetragonal structure with α=3.851Å and c=10.941Å, while an orthorhombic supercell of α×4α×2c forms, most probably as a result of ordering of carbon vacancies along the b-axis. An irreversibility line was measured under magnetic fields up to 5T.抄録全体を表示PDF形式でダウンロード (2569K) -
武田 保雄, 橋本 裕司, 今西 誠之, 山本 治1994 年 41 巻 12 号 p. 1475-1480
発行日: 1994/12/15
公開日: 2009/05/22
ジャーナル フリーThe perovskite solid solutions, LaFe1-xCuxO3 and LaFe1-xCuxO3-z were prepared under high oxygen pressure and the phase relations and electrical properties were investigated. In the system of LaFe1-xCuxO3, orthorhombic type LaFeO3 changed to rhombohedral type LaCuO3 at x=0.6. The electricresistivity of the rhombohedral phase was lower 2 or 3 order in the magnitude than that of the orthorhombic one. In LaFe1-xCuxO3, the oxygen nonstoichiometric samples showed the rhombohedral structure in all x range with metallic conductivity and Pauli paramagnetism. The Seebeck coefficient measurement showed the dominant carriers for x <0.8 are electron, and hole for x>0.8. The perovskite LaFe1-xCuxO3-z is able to have a large amount of oxygen vacancy, where a cubic perovskite like phase having the disordered arrangement is realized.抄録全体を表示PDF形式でダウンロード (261K) -
間崎 啓匡, 安岡 宏, 垣花 眞人, 長田 実, 吉村 昌弘1994 年 41 巻 12 号 p. 1481-1486
発行日: 1994/12/15
公開日: 2009/05/22
ジャーナル フリーWe measured complex susceptibilities of Sr-doped YBa2Cu3O7-d superconductors, YBa2-xSrxCu3O7-d (x=0-1.0) and determined the onset temperature of the superconducting transition. The samples were synthesized by the modified polymerized complex method. With increasing x, the onset temperature decreased, although the depletion was not large as those for Sr-doped YBa2Cu4Oy. Measurements of the phonon Raman spectra have revealed that with increasing x the frequencies of the Ba, Cu(2) and apex oxygen O(4) vibrational modes along c-axis change. Besides, at about 570 cm-1, a small growth of a peak was observed with increasing x, which may be caused by oxygen disorder in the CuO chains. But no appreciable changes in hole density were found from optical absorption spectra.抄録全体を表示PDF形式でダウンロード (313K) -
長田 実, 垣花 眞人, 八島 正知, 吉村 昌弘, 間崎 啓匡, 安岡 宏1994 年 41 巻 12 号 p. 1487-1491
発行日: 1994/12/15
公開日: 2010/11/19
ジャーナル フリーPhonon Raman spectra of the modulation-free Bi1.2 Pb0.8 Sr2 Ca1-y, YyCu2Oz(0.2≤y≤0.8) have been investigated both in polycrystalline and single crystal forms. Polarized Raman spectroscopic measurements of single crystals made it possible to clarify some controversies on the Raman mode assignments for Bi2 Sr2 CaCu2 O8+d (Bi2212), most notably in high-frequency three prominent oxygen modes observed at 290, 460 and 630cm-1, which we assigned to AgOBi+B1gOCu, Ag OBi and Ag Oap _??_ x, respectively. The energies of the three oxygen modes show drastic change with a decrease of the hole concentration: (1)Ag OBi+B1g OCu. mode is shifted towards higher frequencies, (2)AgOBi mode hardly varies for y<0.6, while softens for y>0.6, and Ag Oap _??_ x mode is shifted towards lower frequencies. The observed changes in these oxygen modes are similar to those observed for the modulated Bi2 Sr2 Ca1-y Yy Cu2Oz. We propose that the Y/Ca substitution both in the modulated and modulation-free Bi2212 systems induced a hole filling on the CuO2 plane, which can explain the behaviour of the oxygen modes observed in their Raman spectra.抄録全体を表示PDF形式でダウンロード (302K) -
林 真人, 福原 実, 土井 章, 小林 斉也, 池田 靖訓, 高野 幹夫, 坂東 尚周, 草野 圭弘, 高田 潤1994 年 41 巻 12 号 p. 1492-1496
発行日: 1994/12/15
公開日: 2009/05/22
ジャーナル フリーThe compositional range and the structure of the solid solution of the Pb-added 2212 phase
has been studied in Bi2Sr3-xCaxCu2PbyOz heated in Ar at 795°C to 822°C. The monophasic compositional range increases as x decreases. For x=1.25 monophasic products with y≤0.6 can be obtained. The structure symmetry changes from tetragonal in y≤0.3 to orthorhombic in y≥0.4. The monophasic compositional range and the Pb-compositional dependence of the lattice parameters in the Pb-added 2212 phase are remarkably different from those in Bi2-yPbySr1.5Ca1.5Cu2Oz reported so far. Tc decreases as y increases.抄録全体を表示PDF形式でダウンロード (1920K) -
草野 圭弘, 難波 徳郎, 高田 潤, 池田 靖訓, 高野 幹夫, 板東 尚周1994 年 41 巻 12 号 p. 1497-1500
発行日: 1994/12/15
公開日: 2009/12/04
ジャーナル フリーRefining behavior due to a small mechanical force and re-formation process of the 2223 phase on heating have been examined for the samples with a nominal composition of Bi1.8Pb0.4Sr2Ca2Cu3.2Oz by XRD, TEM, ED, AFM and TG-DTA. The 2223 phase is brittle and easily cleaved at Bi-O double layers in its crystals by a small mechanical force, resulting in changing into the superfine powder with a thickness of 1/2c. On heating the ground powder at 500°C to 800°C in air, various phases were formed from the superfine powder.抄録全体を表示PDF形式でダウンロード (1452K) -
草野 圭弘, 大上 洋一, 難波 徳郎, 高田 潤, 池田 靖訓, 高野 幹夫, 坂東 尚周1994 年 41 巻 12 号 p. 1501-1504
発行日: 1994/12/15
公開日: 2009/12/04
ジャーナル フリーPining characteristics due to the precipitates of the "3321"(Sr2.5Bi0.5Pb3Ca2CuOz) phase have been studied in the Bi-2223 phase in the Bi-Pb-Sr-Ca-Cu-O system by mainly XRD and magnetic measurements. The precipitation of the "3321" phase was controlled by changing annealing temperature and annealing time in air. On annealing at 750°C for 10min and 1h, the larger hysteresis loops in M-H curves were observed in comparison with the initial one before annealing. However, the hysteresis loops became smaller with increasing precipitation of the "3321 " phase. Furthermore, the 2223 phase annealed at 400°C and 500°C, in which no precipitation of the "3321 " phase was observed, exhibits larger hysteresis loops.抄録全体を表示PDF形式でダウンロード (242K) -
西坂 強, 羽根 晶, 星野 和友1994 年 41 巻 12 号 p. 1505-1509
発行日: 1994/12/15
公開日: 2009/05/22
ジャーナル フリーThe effect of a combination process with intermediate pressing and sintering on critical current density, Jc, has been studied for the high-Tc Bi system with the nominal composition of Bi1.6 Pb0.5 Sr2.0 Ca2.0 Cu3.0 Oz . The Jc of the plate samples has increased drastically from 200 to 2000 A/cm2 by repeating this process more than one time . A micro-hardness Hv, has been measured as a function of the depth from the sample surface . The Hv in the sample has the maximum value of about 80 on the surface and decreases to 50 at depth below 2mm . From the estimation of experimental data, it has been found that the Jc increases exponentially with the Hv.抄録全体を表示PDF形式でダウンロード (1546K) -
石井 守, 塚本 惠三, 下嶋 浩正, 山岸 千丈, 高田 雅介, 山下 努1994 年 41 巻 12 号 p. 1510-1515
発行日: 1994/12/15
公開日: 2009/12/04
ジャーナル フリーBi(Pb)-Sr-Ca-Cu-O superconducting tubes with different length were fabricated to examine the influence of the length/diameter rate to the magnetic shielding property. As the length/diameter rate increased, the shielding magnetic flux density, at which the flux started to penetrate into the tube center, increased and became constant at length/diameter rate above 1.7. Subsequently, the simulation of the magnetic shielding property was carried with the critical state model. As a result, the simulation result was agreed with the determination result at length/diameter rates above 1.7. However, at length/diameter rates below 1.7. there was differential to the simulation result and the determination result. This is attributed that the tube was not considered as the infinite length tube. Furthermore, the simulation was carried with the Biot-Savart's law. As a result, simulation result of the magnetic shielding property of the tube which contained the short tube, agreed with the determination result smartly.抄録全体を表示PDF形式でダウンロード (292K) -
宮沢 肇, 堀田 勝喜, 船戸 健一, 村川 正夫, 廣瀬 治男1994 年 41 巻 12 号 p. 1516-1519
発行日: 1994/12/15
公開日: 2009/05/22
ジャーナル フリーPossibility of joining of supercondoctor bulks through laser treatment was discussed. A 4.0×4.5×2.0 mm Bi system bulk was used as the material to be joined. Paste of powder of the same phase, which was dispersed in various kinds of solvents such as distilled water, nitric acid (5wt%), ethyl alcohol and 2-butoxyethyl acetate, was used as the medium material. Two pieces of bulk filled with the medium material between them were installed on a jig system and settled on an X-Y table, followed by laser beam irradiation. A 200 W output CO2 laser beam accompanied by oxygen gas blow was irradiated onto the medium along the contact line at a speed 10mm/min. The specimen pasted with 2-butoxyethyl acetate show Tc(on) in electric resistance after laser irradiation. SEM images of the joint after laser irradiation reveal improvement of crystallinity. Those results indicate the possibility of connection of superconducting bulks through laser treatment.抄録全体を表示PDF形式でダウンロード (1165K) -
高畠 進義, 坪田 崇, 石川 敏章, 大橋 憲太郎1994 年 41 巻 12 号 p. 1520-1523
発行日: 1994/12/15
公開日: 2009/12/04
ジャーナル フリーBi-Pb-Sr-Ca-Cu-O superconducting films were prepared on poly- or single crystal MgO substrate by sol-gel method. For the starting solution, we used acetates-solutes propionic(C2H5COOH) or butyric acid(C3H7COOH) with or without the addition of aqueous ammonia. The films were prepared by repeating the process of coating and decomposition(at 700°Cfor30 min) 3-10 times and by fin ally sintering at 855°C for 12h. The increase of CH2 number of solvent and the addition of NH3⋅H2O increase the values of pH and viscosity of the solution. These increases make a film twice thickerthan the film obtained from propionic acid solution. For the film sample prepared using butyric acid solution with 6 vol% of NH3⋅H2O, the percentage of high-Tc phase was determined by XRD(002) lines to be 40%, which was higher by 7% than that of the film prepared using propionic acid solution. The highest value of Tco(77K) was obtained for the film using butyric acid-NH3⋅20 system.抄録全体を表示PDF形式でダウンロード (1361K) -
坪田 崇, 石川 敏章, 大橋 憲太郎, 高畠 進義1994 年 41 巻 12 号 p. 1524-1527
発行日: 1994/12/15
公開日: 2009/12/04
ジャーナル フリーWe prepared Bi-Pb-Sr-Ca-Cu-O superconducting films on single crystal MgO substrate by sol-gel method. As the starting solution, we used the propionic or butyric acid solution prepared by solving acetates or 2223 phase powder. MgO substrate was coated with the starting solution using a spin coater and heated for 30min at 700°C. This process was repeated several times and the film was heated at 855°C for less than 24h. The film samples obtained from acetates-solute butyric acid were soaked in water or acetone in order to study their effect on Tco. The Tco of sample soaked for 24h in water was lower by 5K than that of sample before soaking(Tco=77K). For the films obtained from 2223 oxide-solute propionic acid, the percent of 2223 phase increased from 0 to 30% when the sintering duration at 855°C increased from 1 to 12h.抄録全体を表示PDF形式でダウンロード (196K) -
貞広 嘉和, 本田 宏隆, 小石 真純1994 年 41 巻 12 号 p. 1528-1531
発行日: 1994/12/15
公開日: 2009/05/22
ジャーナル フリーThe ingredients of Y2O3, BaCO3, and CuO were treated by a hybridization milling apparatus, pressed at 500kg/cm2 and calcined at 925°C for 2 days, followed by annealing at 500'C for 7 days. The milling effects on the samples were inferred from the analysis of the X-ray peaks and SEM observation. It has been clarified that the ingredient materials is very well mixed by milling for 20 minutes, so that the calcined sample may be very good superconductor.抄録全体を表示PDF形式でダウンロード (1496K) -
上道 雅丈, 井上 博史, 稲数 直次1994 年 41 巻 12 号 p. 1532-1537
発行日: 1994/12/15
公開日: 2009/05/22
ジャーナル フリーTo assess the alignment of Bi2Sr2CaCu2Ox crystallites for silver sheathed tapes, we analyzed quantitatively the crystallographic textures by using the crystallite orientation distribution functions (ODF). The tapes were prepared from the calcined or completely sintered powder by the powder-in-tube method which involved tubing, drawing, rolling and sintering process. The ODF's were determined from measured incomplete pole figures using the series-expansion method. The c-axis in heavy rolled specimens was inclined slightly from the normal direction of the tapes toward the rolling direction. In the tapes prepared from the calcined powder, the heavy drawn specimens showed a strong preferred orientation in the a -b plane such as (001)[110]. In the case of the sintered powder, heavy rolling led to the remarkable development of textures. The results imply that the ON analysis is necessary for preparation of oxide superconductor tapes.抄録全体を表示PDF形式でダウンロード (395K) -
M.A.E. Saleh, Susumu Shima1994 年 41 巻 12 号 p. 1541-1546
発行日: 1994/12/15
公開日: 2009/05/22
ジャーナル フリーParticle shape and particle strength in addition to the powder material, particle size distribution and inter-particle characteristics have great influence upon tap density, densification mechanisms and compressibility of a powder and therefore upon density distribution inside a compact. An attempt is made to investigate the effect of those powder characteristics on constitutive behavior during compaction of powder and thus to incorporate them into constitutive equations developed in the past. Since tap density appears to be a good measure to represent the characteristics of the powder, a new expression that include it is proposed, and the densification mechanism is discussed. It is thus shown by experiment on various copper powders that when the powder is of a narrow size distribution the parameters included in the equation are uniquely determined regardless of the particle shape, i.e dendrytic, irregular or spherical. When particle sizes are widely distributed, on the other hand, they are not determined uniquely. Some of the parameters are the same for all the powders, but they differ from powder to powder and according to the compaction stage.抄録全体を表示PDF形式でダウンロード (385K) -
吉田 秀人, 宮田 昇, 山岸 千丈1994 年 41 巻 12 号 p. 1547-1552
発行日: 1994/12/15
公開日: 2009/12/04
ジャーナル フリーRelation between three point bending strength of mullite ceramics and their defects is studied. From SEM analysis of specimens after three point bending test, origin of fracture was mainly due to pores exsisting in specimens. Position of pores depended on specimens and shapes of pores were irregular shapes.Stresses loaded on defects are about 80-90% of bending strengths. Experimental equation of the relation between stress and defect is σ=1420/C1/2, while σ= 1070/C1/2 is obtained by Griffith's theoretical equation in case of sphere defect . Maximum mainstress is calculated by FEM on the assumption that shape of defect are oval (radius ratio: a/b). The maximum main stress of oval defect changed about ± 30% in comparison with that of sphere defect in the range of a/b = 0.5-2.0.抄録全体を表示PDF形式でダウンロード (1507K) -
高田 仁輔, 河合 伸泰1994 年 41 巻 12 号 p. 1553-1559
発行日: 1994/12/15
公開日: 2009/05/22
ジャーナル フリーThe dimensional changing behavior of the system Fe-2wt%.Cu-0.8wt%C-0.75wt% zinc stearate under an atmosphere of endothermic gas was investigated. The decrease of heating rate causes shrinkage and the decrease of cooling rate causes expansion. On the other hand, the influence of the dew point on dimensional change is also in accordance with tendency of heating and cooling rate. It became clear by two model experiments that the compacts shrink with carburizing during heating and expand during cooling.
In this way, dimensional change depends on carburization, but the behavior observed during heating differs from that during cooling. Authors proposed the new "carbon transfer theory ". When this theory was applied to various sintering phenomena, experimental results could be explained well. In order to solve problems during the sintering process, it must be important to consider the stage where carbon transfer occurrs.抄録全体を表示PDF形式でダウンロード (466K) -
河本 修1994 年 41 巻 12 号 p. 1560-1563
発行日: 1994/12/15
公開日: 2009/12/04
ジャーナル フリーFerromagnetic resonance measurements at 34 GHz were carried out to study the magnetic anisotropy field of the acicular Fe particles in the commercially available particulate metal tapes for audio recording. The value of the average anisotropy field due to the acicular shape of the oriented particles has been determined to be 603 kA/m assuming the saturation magnetization (M) of 1.72 T, 80% of bulk Fe. The axial ratio of the acicular particles is 4.8, which is in good agreement with the observed value by TEM. The linewidth of 400 kA/m along the tape length direction is four times as large as that of video Co-y-Fe2O3, tapes, which is due to a large distribution of the Fe particle axis.抄録全体を表示PDF形式でダウンロード (1235K) -
1994 年 41 巻 12 号 p. 1565
発行日: 1994年
公開日: 2009/05/22
ジャーナル フリーPDF形式でダウンロード (37K)
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