【摘要】 研究了经过高温热处理而失去超导电性的YBCO(Y-Ba-Cu-O)超导块材经过后氧化热处理恢复其超导性能的可行性,为YBCO超导块材的连接奠定基础。对原始YBCO块材、热处理后YBCO块材及后氧化热处理YBCO(块材和粉末)的超导性能、微观组织及物相变化进行了分析。结果表明:采用常规顶部籽晶熔融织构生长法制备的YBCO块材经过高温热处理后会完全失去超导性;经过后氧化热处理后,其超导性能得到恢复。高温热处理并未改变块材的织构特征,而其晶体结构由正交结构转变成四方结构,从而失去超导性能;经过后氧化热处理,其晶体结构又由四方结构转变为正交结构,完全恢复了超导性能。更多还原

【Abstract】 Single domain yttrium-based(Y-Ba-Cu-O,YBCO) bulk materials exposed to high temperature cycles lose their superconducting ability.This study analyzes the ability of post oxygenation treatment on the recovery of the superconducting ability for joining the YBCO blocks.The superconducting ability,the microstructures,and phase constitution of the original YBCO blocks,post-heat treatment YBCO blocks,and post-oxygenation treatment YBCO blocks and powders.The results show that a top seeded melt-textured growth YBCO block loses its superconducting ability after a welding heat cycle and that the superconducting property recovers completely after heat treatment in flowing oxygen.The texture characteristics of the YBCO block are not obviously changed by the welding heat cycle;however,the block crystal structure is transformed from an orthorhombic structure to a tetragonal structure,which leads to the loss of the superconducting ability.After the post-oxygenation treatment,the block crystal structure changes from the tetragonal structure back to the orthorhombic structure to recover the superconducting ability.更多还原