Y2BaCuO5粒子掺杂的单畴熔融织构YBCO超导体工艺与性能研究

采用人工掺杂Y-211相的方法以及熔融织构生长结合顶部籽晶工艺制备了不同211粒子含量的 准单畴熔融织构的YBCO块材料，样品致密度高，体密度大于62g/cm³，机械强 度好，振动样品磁强计测量结果表明，样品在温度30K、磁场06T下，其J_c仍 达到123×10⁶A/cm².在温度70K、磁场2T条件下，J_c 仍高达135×10⁴A/cm²，而且临界电流密度对磁场不敏感.扫描电 子显微镜分析也表明，Y-211相的人工掺杂，能改善织构样品的生长状况，减小微裂纹，同 时，掺杂的Y-211粒子能作为强的钉扎中心，因此，这种工艺能精确地控制样品中Y-211粒子 的含量，所制备的样品中Y-211粒子分布越均匀，尺寸越小，其钉扎效果越好.从大量实验结 果比较得出，1∶05是最佳的掺杂比例.关键词：准单畴超导体熔融织构c')" href="#">临界电流密度J_{c磁通钉扎中心}

STUDY ON THE TECHNOLOGY AND PROPERTY FOR Y2BaCuO5 PARTICLE S ARTIFICIAL DOPING TO OBTAIN SINGLE-CRYSTAL DOMAIN MELT-TEXTURED YBCO BULK SUPE RCONDUCTOR

This paper describes the method of artificial doping Y-211 phase and melt-textur ed growth with a top-seeded technique to prepare the quasi-single crystal domain YBCO bulk materials with various Y-211 particle contents.The specimens obtained have high density (more than 62g/cm³) and good mechanical toughnes s.The J_c of specimens reaches 123×10⁶A/cm² u nder 06T at 30K and 135×10⁴A/cm² under 2 T at 70K.The scanning electron microscope observation of specimens indicates that Y-211 part icles can improve the quality of melt-textured YBCO superconductor and reduce th e microcrack of specimens.Combining the microstructures with J_c measu rements shows that the smaller the particle size,the more homogeneous the partic le distribution,the higher the pinning effectiveness.The best ratio of Y-123 to Y-211 for the superconductor specimens is 1∶05 in moles,in which the Y-211 pa rticles are uniformly distributed and their size is about 200nm.