【摘要】 我们对低温下YBCO(1 2 3)超导薄膜样品中磁通的宏观量子蠕动效应进行了研究 .用SQUID磁强计测量了厚度分别为 2 .4nm、6.0nm、1 0 .8nm和 40 .0nm的YBCO超导超薄膜样品和厚为 2 0 0nm的YBCO薄膜样品的磁化弛豫性质 .通过对样品磁化弛豫性质的分析我们在YBCO超导超薄膜样品中观察到明显的磁通的宏观量子蠕动效应 .各样品发生量子蠕动效应的温度Tcr在 8～1 5K之间 ,大大高于以前人们在YBCO单晶样品中观察到的 1K的结果更多还原

【Abstract】 Magnetic relaxations of YBCO films with thickness ranging from 2.4nm to 200nm have been studied using a commercial SQUID. Magnetic relaxation measurements show strong quantum creeping effects at temperatures as high as 8.5～15K in ultra thin films (2.4～40nm), whereas in 200nm film it is dominated by thermal activation down to \{4.2K\}. The T\-\{cr\} of ultra thin films is much higher than that reported in YBCO thick films or single crystals by others.更多还原