不同粒径Gd2Ba4CuNbOy纳米粒子掺杂对GdBCO块材性能的影响

Effect of the Different Particle Sizes Gd2Ba4CuNbOy Nanoparticles Doping on the Properties of GdBCO Bulk Superconductor

采用顶部籽晶熔融织构方法（TSMTG）成功制备出掺杂不同粒径Gd_2Ba_4CuNbO_（？）纳米粒子的单畴GdBCO超导块材,研究其对超导块材的生长形貌和磁悬浮力的影响,结果表明,在该条件下制备出的单畴GdBCO超导块材样品上表面十字花纹明显,且四个单畴扇区光滑平整;样品的磁悬浮力随着Gd_2Ba_4CuNbO_y粒径的增大有逐渐减小的趋势,当过筛目数n=360目时,样品的磁悬浮力最大,约25N;利用环境扫描电子显微镜技术（SEM）观察了样品的微观形貌,结果显示,随着掺杂粉体过筛目数的减小,样品中Gd_2Ba_4Cu NbO_y纳米粒子的分布越来越均匀且粒径逐渐增大。

Single domain GdBCO bulk superconductors doped with Gd_2Ba_4CuNbOy nanoparticles of different particle sizes have been successfully fabricated by the top-seeding melt texture growth process（TSMTG）.The effect of Gd_2Ba_4GuNbOy nanoparticles of different particle sizes on the growth morphology and the magnetic levitation force properties of single domain GdBCO bulk superconductors have also been investigated.The result shows that single domain GdBCO bulk samples can be fabricated,the surface of the samples has significant cross pattern and four single domain sectors become smooth and flat.The magnetic levitation force of samples decrease gradually with the increase of Gd_2Ba_4CuNbOy particle sizes,the largest levitation force of 25N is obtained in the samples with n=360;The morphology of the samples arc observed through environmental scanning electron microscope（SEM） technology.The result shows that the distributions of Gd_2Ba_4CuNbOy nanoparticles for samples become more uniform and the particle sizes increase gradually with the decrease of the sieve mesh for doped powders.The research results have significance impact on further improving the properties of GdBCO bulk superconductors.