熔融织构YBa_2Cu_(2.99)Li_(0.01)O_y的交流磁化性质  

AC SUSCEPTIBILITY PROPERTIES OF MTG -YBa_2Cu_(2.99)Li_(0.01)O_y CRYSTALS

作　　者：李配军[1] 王智河[1] 聂阳[1] 白忠[1] 邱里[1] 丁世英[1] 张宏[2] 

机构地区：[1]南京大学物理系固体微结构国家重点实验室,南京210093 [2]中科院上海微系统与信息技术研究所,上海200050

出　　处：《低温物理学报》2005年第A01期475-479,共5页Low Temperature Physical Letters

基　　金：国家自然科学基金(批准号:10174033);南京大学测试基金和预研基金资助的课题~~

摘　　要：在不同直流磁场、交流磁场和频率下测量了熔融织构YBa2Cu2.99Li0.01Oy样品交流磁化率的温度关系.基于非线性磁通耗散理论,研究了交流场的大小和频率对χ″的峰值温度Tp的影响,获得了磁通有效钉扎势与温度、直流场和电流密度的关系,U(J,Hdc,T)(J-(Hdc-0.75(1-T2/Tc2)3/2,其中μ约为0.13与理论预期的μ=1/7相一致,表明该样品中可能存在涡旋玻璃相变.The AC susceptibility of MTG-YBa2Cu2.99Li0.01Oy sample was measured as a function of temperature with different dc field, ac field and frequency. The effects of Hac and f on the peak temperature Tp in x″ were analyzed based on nonlinear flux diffusion theory, we obtain the relation of the flux effective pinning barriers with temperature, dc field and the density of current, U（J,Hdc,T）∝J^-μHdc^-0.75（1-T^2/Tc2）^3/2 , and the value of μ is about 0.13,it is consistent with the predict by theories, the result shows vortex-glass phase in the sample is possible.

关 键 词：高温超导体 磁通钉扎 

分 类 号：O513[理学—低温物理]