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采用人工掺杂Y 2 11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 2 11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Jc 仍达到 1 2 3× 10 6A/cm2 .在温度 70K、磁场 2T条件下 ,Jc 仍高达 1 35× 10 4A/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 2 11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 2 11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 2 11粒子的含量 ,所制备的样品中Y 2 11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 .
YBCO bulk materials with different 2 11 particle sizes were prepared by artificially doping Y 2 11 phases and fused texture growth combined with a top-seed process. The YBCO bulk samples with high density and bulk density of more than 62 g / cm3, the mechanical strength is good, the measurement results of the vibrating sample magnetometer show that the Jc still reaches 123 × 10 6A / cm2 at a temperature of 30 K and a magnetic field of 0 6 T. The Jc is still as high as 70 K at a magnetic field of 2 T 1 35 × 10 4A / cm 2, and the critical current density is insensitive to the magnetic field.Search electron microscopy also showed that the artificial doping of Y 2 11 phase can improve the growth of textured samples and reduce the microcracks, meanwhile, Y 2 11 particles can be used as a strong pinning center. Therefore, this process can precisely control the content of Y 2 11 in the sample. The Y 2 11 particles in the prepared sample have a more uniform distribution and smaller size, The better the pinning effect.From the results of a large number of experiments, 1:05 is the best doping ratio.