高温超导体临界电流的测量  

MEASUREMENT OF CRITICAL CURRENT FOR HIGH TEMPERATURE SUPERCONDUCTORS

作　　者：刘先昆[1] 罗虹[1] 张莉[1] 乔硚[1] 丁世英[1] 徐健健[1] 

机构地区：[1]南京大学物理系,南京210093

出　　处：《低温物理学报》2006年第4期359-367,共9页Low Temperature Physical Letters

摘　　要：本文报道高温超导体临界电流测量若干问题的研究.电磁测量和数值模拟指出,对于高温超导体,电输运法测量的临界电流可能与电流扫描速度有关,快速扫描,特别是脉冲法测量的临界电流将偏小;磁滞回线法测量的临界电流与磁场扫描速度有关,快速磁场扫描测量时临界电流的判据较大;交流磁化率法测量的临界电流与交流频率有关,使用高频测量时临界电流的判据较大.这些特征和临界态模型的预言不同,都与高温超导体的特征有关.We study experimentally and numerically the measurement of criticul current for high temperature superconductors. It is shown that criticul current of high temperature superconductors depends on sweeping rate of applied current dⅠ/dt in transport measurement. The critical current measured by current pulse method will be smaller than that determined by dc transport. The magnetic critical current by magnetic hystersis loop is dependent on field sweeping rate dH/dt and Jc determined by ac susceptibilty depends on the ac frequency. All the dependeces originate from the gaint flux creep.

关 键 词：临界电流 磁通蠕动 高温超导体 

分 类 号：O511.4[理学—低温物理]