BiPbSbSrCaCuO非晶态及热处理对其影响  

A STUDY ON NON-CRYSTALLINE BiPbSbSrCaCuO AND ITS HEAT TREATMENT EFFECT

作　　者：张宏[1] 吴鸿[1] 胡素辉[1] 

机构地区：[1]中国科学院上海冶金研究所,上海200050

出　　处：《低温物理学报》1993年第6期445-449,共5页Low Temperature Physical Letters

基　　金：国家超导技术联合研究开发中心;国家自然科学基金

摘　　要：本工作用正电子湮没谱术(PAS),X射线衍射谱(XRD),示差热分析(DTA),扫描电镜显微术(SEM)和交流磁化率(X_(?))研究了Bi-Pb-Sb-Sr-Ca-Cu-O非晶态和后续热处理的影响。结果表明:所研究的非晶态晶化温度T_c-450-470℃,当热处理温度T_o<T_c,非晶态历经低温结构弛豫和高温结构弛豫。当T_o>T_c,在晶态多相体系中随温度升高发生低n相向高n相的转变。850℃退火可使超导转变温度达110K,正电子湮没寿命谱对Bi系非晶态晶化敏感,非晶态中正电子抽样的电子密度高于晶态。Pb和sb的同时掺入有利于高温熔体凝固为非晶态,但缩小了玻璃粘滞态的温度范围。In this work Positron Annihilation Spectroscopy, X Ray Diffraction, Differential Thermal Analysis, Scanning Electron Microscopy and ac susceptibiity measurment have been used to study non-crystalline Bi-Pb-Sb-Sr-Ca-Cu-O and the effect of heat treatment. The crystallization temperature Tc is around 450-470℃ for investigated materials. There are low temperature and high temperature structure relaxation as in metallic glasses from room temperature to glass temperature. For T >Te in the cryt-stailized multiphase the low n phase can transform to high n phase by reaction diffustion and Tc can reach near 110K by 850℃ annealing. The positron annihilation characteristics are sensitive to phase transformation and the electron density sampled by positrons in the non-crystal is lower than that in crystallized one. The doping of Pb and Sb together is of benefit to forming of noncrystal but narrowes the temperature range of the viscous state.

关 键 词：非晶超导体 超导性 热处理 

分 类 号：O511.1[理学—低温物理]