高温超导体涡旋玻璃态的临界电流密度  

CRITICAL CURRENT DENSITY IN VOTEX GLASS PHASE FOR HIGH TEMPERATURE SUPERCONDUCTORS

作　　者：林建伟[1] 丁世英[1] 姚希贤[1] 

机构地区：[1]河海大学数理系,南京大学物理系和固体微结构物理实验室

出　　处：《低温物理学报》1996年第1期51-57,共7页Low Temperature Physical Letters

摘　　要：研究了高温超导体涡旋玻璃态的临界电流密度。Ｊｃ结果表明，决定这种Ｊｃ的主要因素除了磁通钉扎能以外，还有能量函数—有效热激活能Ｕ．提出了根据Ｕ函数求，Ｊｃ的方法，证明Ｊｃ不但与温度和磁场有关，而且还特别显著地依赖于电场（或时间）判据，后者是高温超导体弛豫时间常数很小的结果．利用交流磁化率方法测得ＨｇＢａ２Ｃａ２Ｃｕ３Ｏｙ样品的Ｕ对Ｊｃ进行了估计．同时应用Ｂｅａｕ模型和磁滞回线实验结果计算了Ｊｃ并与上述Ｊｃ结果作了比较，表明在判据相同时两种Ｊｃ能互相吻合．本法预言，输运方法测量的Ｊｃ比磁Ｊｃ要高一个量级．Abstract Critical current density J. of high temperature superconductors in votex glass phase has been studied.It is shown that the J. is determined mainly by the energy function-the effective thermal activiation energy U besides the flux pinning force. A procedure is proposed to determine the J.according to the U function. showing the J. is dependent not only on temperatureand magmetic field, but also apparently on electric field (or time) criterion which is the result of the small relaxation time scale. The J. of HgBa2Ca2Cu3Oy sample has been estimated based on the U obtained by means of ac susceptibility method. The J. is also calculated from the Beau model and the hysteresis results. The comparisons are made and show that the J. with same cretrion are in agreement well with one another. It is predicted that the J. with transport criterion is higher than the magnetic one for approximately one order.

关 键 词：临界电流密度 超导体 高TC 涡旋玻璃态 

分 类 号：O511.2[理学—低温物理]