高温超导体磁化强度弛豫与CuO_2层间耦合之间的关系研究  

INVESTIGATION OF THE RELATIONSHIP BETWEEN MAGNETIC RELAXATION AND CuO_2 INTERLAYER COUPLING IN HIGH TEMPERATURE SUPERCONDUCTORS

作　　者：孙雅琴[1] 冯双久[1] 李广[1] 时亮[1] 李晓光[1] 

机构地区：[1]中国科学技术大学结构开放实验室

出　　处：《低温物理学报》2002年第2期87-91,共5页Low Temperature Physical Letters

基　　金：国家重点基础研究 (NKBRSF G19990 6 4 6 0 3);国家自然科学基金 (批准号 :5 0 0 72 0 10 )资助项目~~

摘　　要：本文研究了HgSr2 Ca0 .7Y0 .3Cu1.8Re0 .2 Oz 和Hg(Ba0 .5Sr0 .5) 2 CaCu1.8Re0 .2 Oz(Hg12 12 )超导体的磁化弛豫 ,发现磁化弛豫偏离了对数时间依赖关系 .采用指数弛豫表达式M =M0 +M1t-α ,可以很好地拟合Hg基超导体的磁化弛豫 .通过比较Hg12 12、YBa2 Cu3O7-δ 和Bi2 Sr2 CaCu2 O8的磁化弛豫行为 ,研究了磁化弛豫率和钉扎势随CuO2 层间距离的变化关系 ,发现磁化弛豫率随层间距离增大而增大 ,而钉扎势则随之增大而减小 .Magnetic relaxation in HgSr\-2Ca\-\{0.7\}Y\-\{0.3\}Cu\-\{1.8\}Re\-\{0.2\}O\- z and Hg(Ba\-\{0.5\}Sr\-\{0.5\})\-2CaCu\-\{1.8\}Re\-\{0.2\}O\- z (Hg1212) has been investigated in this paper. It is found that the magnetic relaxation deviates from the linear logarithmic time dependence and fits well to the exponential relaxation relation \$M=M\-0+M\-1t\+\{-α\}\$. The variation of magnetic relaxation rate and pinning potential on interlayer distance is discussed by comparing the relaxation behaviors of YBa\-2Cu\-3O\-\{7- δ \}, Bi\-2Sr\-2CaCu\-2O\-8, and Hg1212 systems. The magnetic relaxation rate increases with increasing interlayer distance, on the contrary the pinning potential decreases with increasing interlayer distance.

关 键 词：高温超导体 磁化强度 CuO2 层间耦合 磁化弛豫 磁化弛豫率 钉扎势 氧化铜 

分 类 号：O511[理学—低温物理]