YBaCuO超导陶瓷的有效钉扎力

提出了有效钉扎力的概念,并由此建立了描述有大量内界面的陶瓷样品滞迴行为的方法。测量了烧结YBaCuO陶瓷样品的剩余磁化强度与磁化场及温度的关系,并用有效钉扎力方法从中萃取了有效钉扎力,它有两项:一项与磁化电流相联系,并受界面间的弱连接控制;另一项来自颗粒体内的钉扎中心控制。弱外磁场中前一种起主要作用,强场中后一种居主导。 关键词：

THE EFFECTIVE FLUX PINNING FORCE OF SUPERCONDUCTING CERAMIC YBaCuO

Based on the concept of effective flux pinning force proposed by the present authors, a method desoribing hysteresis of superconducting ceramic samples with great number of interfaces has been established. The dependences of residual magnetization on magnetizing field and temperature were measured and the effective flux pinning force was extracted from the magnetizations according to the method mentioned above. The force consisted of two types, one of which results from interface magnetic currents which conduct the force to crystal lattice directly, and governed by weak links if there are. The other arises from the flux pinning of intragrain pinning centres. The former is important in small fields whereas the later is dominant in high fields.