Investigation of Proximity Effects between Normal Metal and Superconductor through Transmission Electron Spin Resonance and Microwave Magnetoabsorption

通过透射电子自旋共振和微波磁吸收研究普通金属与超导体之间的邻近效应

• 批准号: 03650024
• 负责人: NISHIDA Akihiko
• 金额: $ 0.77万
• 依托单位: Fukuoka University
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for General Scientific Research (C)
• 财政年份: 1991
• 资助国家: 日本
• 起止时间: 1991 至 1992
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-03650024/
• 关键词: TESR; Microwave Absorption; Cuprate superconductor; Rietveld Analysis; Flux Pinning; Logarithmic Relaxation; Viscous Flux Motion; 2D Flux Lattice; 高温超伝導; 不可逆線; 近接効果; 高温超伝導体; 二次元超伝導; スケ-リング則

The results of this project, regarding the interaction between superconductors and resonant / non-resonant microwaves as an woof, is summarized below.(1) Fabrication of a simple resistivity cryostat and Y- and Bi- based high-T_c superconductors resulted in a fairly satisfying source material for electron-beam evaporation in YBCO case. In BSCCO case, however, there remained some problems for improving homogeneity of oxygen concentration within the sample.(2) Close correlations among sintering conditions, oxygen contents and superconducting qualities have been confirmed mainly in YBCO through X-ray diffraction and Rietveld analyses. This has been one step towards studies of correlation between flux-pinning defects and oxygen deficiency.(3) The necessity of rather sharp transition of superconductivity as well as moderate coupling between normal metal and superconductor has been pointed out for the distinct proximity effect to be clearly observed through measurements of the transmission el … More ectron spin resonance.(4) The detailed observations of the microwave magnetoabsorption have shown that superconductivity in the Tl-based cuprate is quasi-two dimensional similar to the Bi-based cuprate. The observed logarithmic relaxations in the remanent absorption after H_<FC> field cooling and in the magnetoabsorption under existing field H_a provided estimations of the flux pinning potential U_O which scaled as U_O alpha H^<-1/4>_ and as U_O alpha H^<-1/2>_, respectively. These observations are consistent with the microwave irreversibility measurements with U_O alpha B^<-1/2> dependence which originates in the two-dimensional flux lattice model. Decaying process of the in-field microwave absorption further suggested that the absorption in larger applied field is closely correlated with magnetization |M| rather than flux density B. Further investigations on the interactions between microwaves and superconductors will be continued in the future project accompanied by magnetization measurements in the same samples. Less

本项目以超导体与共振/非共振微波的相互作用为例，总结如下：(1)制作了简单的电阻率恒温器和Y、Bi基高T_c超导体，为YBCO情况下的电子束蒸发提供了一种比较满意的源材料。然而，在BSCCO的情况下，仍然存在一些问题，以改善样品中的氧浓度的均匀性。(2)通过X射线衍射和Rietveld分析，主要证实了YBCO的烧结条件、氧含量和超导性质之间的密切关系。这是研究磁通钉扎缺陷与氧缺乏之间关系的一个步骤。(3)为了通过对el…透射率的测量，清楚地观察到明显的邻近效应，需要相当剧烈的超导转变以及正常金属和超导体之间的适度耦合。更多的电子自旋共振。(4)对微波磁吸收的详细观察表明，Tl基铜酸盐的超导电性类似于铋基铜酸盐的准二维超导电性。H&lt；Fc&gt；场冷却后剩余吸收的对数弛豫和存在磁场H_a下的磁吸收的对数弛豫分别给出了磁通钉扎势U_O的估计值，其标度分别为U_OαH^&1/4和U_OαH^&2。这些观测结果与源于二维磁通晶格模型的U_OαB^&lt；-1/2&gt；依赖测量的微波不可逆性是一致的。场内微波吸收的衰减过程进一步表明，在较大外场中的吸收与磁化强度|M|密切相关，而不是与磁通密度B密切相关。进一步研究微波与超导体之间的相互作用将在未来的项目中继续进行，并伴随着相同样品的磁化测量。较少

项目成果

N.Fuketa, K.Furuya, A.Nishida and K.Horai: "Fabrication of a Simple Resistivity Cryostat and Measurements on Y-based High-T_c Copper Oxide Superconductors" Fukuoka Univ.Sci.Rep.Vol.22. 107-118 (1992)

N.Fuketa、K.Furuya、A.Nishida 和 K.Horai：“简单电阻率低温恒温器的制造和 Y 基高温铜氧化物超导体的测量”福冈大学 Sci.Rep.Vol.22。

Akihiko NISHIDA: "Flux Pinning and Logarithmic Relaxation of Microwave Remanent Ab-Sorption in Superconductiong T1_2Ba_2Ca_2Cu_3O_<10>" Physica C. 185-189. 2153-2154 (1991)

Akihiko NISHIDA：“超导 T1_2Ba_2Ca_2Cu_3O_<10> 中微波残余吸收的通量钉扎和对数弛豫”Physica C. 185-189。

A.Nishida and K.Horai: "In-field Logarithmic Relaxation of Microwave Absorption in Superconducting Tl_2Ba_2Ca_2Cu_3O_<10> and Flux Pinning Properties" Solid State Commun. (1993)

A.Nishida 和 K.Horai：“超导 Tl_2Ba_2Ca_2Cu_3O_<10> 中微波吸收的现场对数弛豫和通量钉扎特性”固态通讯。

Nobuhiro FUKETA: "Fabrication of a Simple Resistivety Cryostat and Measurements on Y-based High-T_C Copper Oxide Superconductors" Fukuoka University Science Reports. 22. 107-118 (1992)

Nobuhiro FUKETA：“简单电阻低温恒温器的制造和 Y 基高 T_C 氧化铜超导体的测量”福冈大学科学报告。

A.Nishida, K.Shiiyama, T.Fujita, H.Shibayama, K.Iwahashi and K.Horai: "Scaling Behavior in the Irreversibility of Tl_2Ba_2Ca_2Cu_3O_<10> Superconductors Investigated through Microwave Absorption" Solid State Commun. Vol.79. 259-263 (1991)

A.Nishida、K.Shiiyama、T.Fujita、H.Shibayama、K.Iwahashi 和 K.Horai：“通过微波吸收研究 Tl_2Ba_2Ca_2Cu_3O_<10> 超导体不可逆性的缩放行为”固态通讯。