YBa_2Cu_3O_(7-δ)超导体的微波特性  

MICROWAVE PROPERTIES OF YBa_2Cu_3O_(7-x) SUPERCONDUCTOR

作　　者：鲍家善[1] 金汴骏 周世平[1] 

机构地区：[1]上海科学技术大学物理系,上海201800 [2]中科院沈阳国际材料物理中心,沈阳110015

出　　处：《低温物理学报》1992年第5期383-389,共7页Low Temperature Physical Letters

摘　　要：本文对YBa_2Cu-3O_(7-δ)材料的表面阻抗的系列研究工作进行了归纳.与经典超导体相比,该类氧化物超导体的微波表面电阻在低温区所呈现的反常,当源于材料的内在特性.我们认为它是材料中存在一定量的未配对载流子所致;而其中 CuO 链的影响是应当考虑的.基于YBa_2Cu_3O_(7-δ)的格胞排序组构,借鉴 Allender 模型,我们提出了修正电导率σ.∝ln(Δ/(?)ω)·[c_1e^(-Δ/K_BT)+(1-c_1)((K_BT)/Δ)]来表征材料的传导电性.基于该设想的微波表面阻抗理论值能很好地吻合实验数据;进而,据此可估计出 YBa_2Cu_3O_(7-δ)的序参数值.如 H_c_1H_c_2,ξ,Δ(0),l.The systematical researches for the surface impedance of YBa2Cu3O7-x superconductors have been revealed. A survey of data between 100 MHz and 150 GHz is given. In comparison to the conventional superconductors, the anomalies of the temperature dependent surface resistance of the oxide superconductors at low temperature are believed to be account for some intrinsic behaviors of the material, and can be explained by the assumption that oxide superconductors contain a significant number of nonpairing charge carries, in which the Cu-O chain role should be considered. Based on the lattice sequence along c-axis and the conducting behavior of YBa2Cu3-O7-δ, a modified conductivity has been suggested. The calculations on microwave resistance on the suggestion have shown excellent agreement with the experimental results.

关 键 词：YBa₂Cu₃O 微波特性 序参数 表面电阻 低温物理学报 块材 表征材料 超导能隙 剩余损耗 定量的 

分 类 号：O4[理学—物理]