Proximity Effect in bilayer films of PrBa2Cu3O7-δ and YBa2Cu3O7-δ

• Main Authors: Yao-Zong Chen, 陳耀宗
• Other Authors: Tzay-Shing Lai
• Format: Others
• Language: zh-TW
• Published: 2001
• Online Access: http://ndltd.ncl.edu.tw/handle/55836173129474273076

碩士 === 中原大學 === 應用物理研究所 === 89 === To understand the behavior of YBa2Cu3O7-χ(YBCO) (S) based junctions having doped YBCO derivatives (N) as a barrier, one has to study both the properties of the individual materials and the proximity effect between them. In the present study we investigated the proximity effect of the N/S bilayers of PrBa2Cu3O7-χ(PBCO) and YBCO that are prepared in-situ in a single deposition run by the 90°off-axis rf magnetron sputtering method. The transport properties of the PBCO/YBCO bilayered structure being explored mainly are : (1)A analysis of the morphology of the N/S interface is to be performed by the atomic force microscopy (AFM). (2)The dependence of the induced superconductivity on the PBCO thickness (dN) and current levels (I) as reveal from the R-T curves. (3)The dependence of IC and TC of the bilayer on the thickness (dS) of YBCO and the thickness (dN) of PBCO. We found an exponential decay of the critical current (IC) with increasing thickness (dN) of the normal metal in the N/S bilayers, IC increases linearly with the increasing thickness dS. A depression of the critical temperature (TC) in N/S bilayers which became larger with decreasing thickness (dS) of the superconductor. From our R-T curves, the induced superconductivity does not exhibit the disappearance- reappearance behavior as the existing data reported. Finally, comments and explanations of our results are presented.