Y_2BaCuO_5粒子对顶部籽晶熔融织构YBCO微结构的影响  

INFLUENCE OF Y_ 2BaCuO_ 5 PARTICLES ON THE MICROSTRUCTURE OF TOP-SEEDED MELT TEXTURED YBCO BULK

作　　者：汪海英[1] 徐克西[1] 杨洋[1] 邱静和[1] 黄参[1] 

机构地区：[1]上海大学物理系,上海200444

出　　处：《低温物理学报》2006年第2期130-133,共4页Low Temperature Physical Letters

基　　金：高等学校博士学科点专项科研基金(项目编号:20040280007);上海市自然科学基金(项目编号:05ZR14051);上海市重点学科建设项目(项目编号:T0104)资助课题.~~

摘　　要：本文主要研究了Y211相粒子在顶部籽晶熔融织构YBCO块材中的分布及其对材料超导特性的影响.研究发现,在籽晶正下方,YBCO超导块材中的Y211粒子分布呈不均匀性.样品在近籽晶处Y211粒子非常少,从样品顶部到样品底部Y211相粒子的容积率呈增大趋势.由于Y123粒子和Y211粒子热膨胀系数存在差异,这种不均匀性导致了块材内部产生微裂纹,从而降低了磁悬浮力.The Y-211 particle distribution within the Melt-Textured Growth （MTG） YBCO bulk, as well as its influence on the bulk superconducting properties, were investigated, It was found that the Y-211 particle distribution within the bulk appears in an inhomogeneous character, which present a gradually changed Y-211 particle density from the upper zone near the top-seed, with nearly little Y-211 particles, to the lower part near the bottom of the bulk with a marked Y-211 particles accumulation. Due to the thermal expansion difference for both of the Y-123 bulk and Y-211 particles the micro-cracks in the bulk interior were consequently brought about, which might result in the bulk levitation force degradation observed in our experiments.

关 键 词：熔融织构块材 Y211粒子分布 微结构 

分 类 号：TM262[一般工业技术—材料科学与工程] TQ325.14[电气工程—电工理论与新技术]