Y_2BaCuO_5粒子在准单畴Y-Ba-Cu-O超导块材中的分布及其对超导性能的影响

Influence of Y_2BaCuO_5 Particles Distribution in Melt-textured Y-Ba-Cu-O Bulk Superconductor on the Superconducting Properties

采用顶部籽晶熔融织构法制备了Y-Ba-Cu-O(YBCO)准单畴超导块材,研究了Y_2BaCuO_5(Y211)粒子在块材中的分布及其对临界电流密度(J_c)和磁悬浮力性能的影响.扫描电子显微镜(SEM)观察发现,Y211颗粒在准单畴超导块材中的分布是不均匀的.实验结果表明,Y211平均粒径的大小与样品的磁悬浮力和临界电流密度成反比,Y211相粒子在母体中的分布越均匀,粒子平均粒径越小,越有利于提高临界电流密度和磁悬浮力.对于(?)20mm的YBCO单畴块材,磁悬浮力可以达到33N(77K,0.55T),临界电流密度达到6.6×10~4A/cm^2.

Single-domain Y-Ba-Cu-O（YBCO） high-temperature superconductor bulk was fabricated by top-seeding melt texture growth process. The distribution of Y2BaCuO5（Y211） particles and its effect on the critical current density （Jc） and levitation force of the bulk samples were investigated. Scan electron microscope （SEM） analysis showed that the distribution of the Y211 particles presented an inhomogeneous character throughout the YBCO matrix. The experimental result also showed that the critical current density and levitation force Y211 particles. The smaller the diameter of the were in inverse proportion to the mean radius of the Y211 particles and the more uniform the distribution of the Y211 particles were, the larger the value of Jc and the levitation force were. For the sample of single-domain YBCO bulk with 20mm in diameter, the levitation force could reach 33N （77K,0.55T） and the magnitude of Jc could reach 6.6 × 10^4A/cm^2.