Pr离子缺陷对Bi-2223/Ag带材磁通涡旋运动的影响  

THE EFFECTS OF Pr-DEFECTS ON FLUX CREEP IN Bi-2223/Ag TAPES

作　　者：蒲明华[1] 曹中胜[1] 郑伟范[1] 赵勇[1] 

机构地区：[1]西南交通大学超导研究开发中心

出　　处：《低温物理学报》2005年第A02期839-843,共5页Low Temperature Physical Letters

基　　金：国家自然科学基金项目NSF-50372051~~

摘　　要：Pr部分替代Ca可以在Bi-2223的超导层中引起局域缺陷(简称Pr离子缺陷),本文分析了不同含Pr量的Bi-2223/Ag带材在垂直于带面的外场下电阻转变特性,研究了其磁通钉扎势垒的变化规律.结果表明:Pr离子缺陷显著提高了Bi-2223带材的磁通钉扎势垒(U).不同含Pr量样品的磁通钉扎势垒(U)均满足U/(1-Tirr/Tc0)(1/Hα的规律,其不同α值反映了样品中不同的磁通蠕动方式.在不含Pr离子缺陷的样品中,磁通主要以双弯结的方式进行蠕动,含Pr离子缺陷的样品中磁通蠕动主要以直接剪切的方式进行.The resistive transitions of （Bi, Pb）2 Sr2Ca2-xPrxCu3Oy silver sheathed tapes with x= 0.0, 0. 001, 0. 002 have been measured under applied magnetic fields oriented perpendicular to tape plane （H//c） from 0 to 7T. The transitions can be well agreed with the thermally activated flux creep model by Anderson： R（T,H） = R0 exp[- U（H）/kBT] in the low resistance range. The calculated activation energies U （H） of flux motion mcreased drastically in the samples with proper amount of Pr-ion defects. For our samples, U are all well fitted with the law of U/（1 - Tirr/Tco） ∝ 1/H^α） , and the markedly changed α indicated the flux creep according to varied manners in different samples. Most of the flux creep by double kinks in the tape without Pr-ion defects, while that through directly lattice shearing in the tapes with Pr-ion defects.

关 键 词：Pr离子缺陷 磁通涡旋运动 BI-2223/AG带材 

分 类 号：O511.4[理学—低温物理]