BiPbSrCaCuO银夹板厚膜边界钉扎效应与磁通蠕动  

INTERFACE PINNING EFFECT AND MAGNETIC FLUX CREEP OF Ag-DOUBLE LAYERED THICK FILM BiPbSrCaCuO

作　　者：韩谷昌 王玉贵[1] 韩汉民[1] 王顺喜[1] 

机构地区：[1]中国科学院等离子体物理研究所,合肥230031

出　　处：《低温物理学报》1993年第4期312-317,共6页Low Temperature Physical Letters

基　　金：国家超导中心资助项目

摘　　要：在低场下测量钉扎力随磁场的变化规律,研究了由晶粒边界引入的弱磁通钉扎和磁通蠕动。发现晶粒边界具有所谓弱钉扎型的钉扎特性,其磁通蠕动和磁通流动性质遵守传统Ⅱ类超导体理论。热激活能(u)可由伏安特性的初始转变区,根据磁通蠕动模型拟合得到,在77K,其值约为90meV,并随磁场升高而减小。在各种传输电流下,测得的电阻降温曲线,显示随测量电流的增加,T_(?)基本不变,但电阻转变明显展宽,T_∞亦随之降低。它们的关系符合小晶粒弱连接钉扎模型,即j_c=(f_p(0)/φ_0)(1-(T/T_c)~3。The weak flux pinning arising from the grain boundary and flux creep were studied in low magnetic field region through the measurement of voltage-current characteristics and field relation of volume pinning force. It was found that the intergrain pinning shows a weak pinning type and related flux creep and flow natures are in agreement with those for conventional type-Ⅱ strong pinning superconductors. The activation energy (U) can be calculated from the initial transition of the voltage-current properties and by fitting with the flux creep model. At 77K, their values are around 90meV and decrease with the increase of magnetic field. Temperature dependence of the resistivity in various constant currents reveals that as the current was raised the Tonset keeps almost unchange, but the resistive transition obviously broadens and Tco, reduces. The relation between. Tco, and the current obeys by the small-grain weak link pinning model, ie, Jc = fp(0)/φ0(l-T/Tc)3.

关 键 词：超导体 磁通钉扎 磁通蠕变 厚膜 

分 类 号：O511.1[理学—低温物理]