中文摘要：

本文利用顶部籽晶熔融织构的方法成功地生长出掺杂不同含量的a-Fe203粉末的单畴GdBazCus07-δ超导块材，并对掺杂后的GdBa2Cu3O7-δ块材的临界电流密度、捕获磁场、微观结构等进行测量和分析．掺杂a-Fe203粉末的摩尔比z分别为x=0，0．1，0．2，0．4，0．8mol％（x为a-Fe203粉末相对于GdBa2Cu3O7—δ的摩尔比）．我们发现在超导块材中掺杂a-Fe203粉末之后，块材的临界电流密度Jc和捕获磁场强度相对于未掺杂的块材有了明显的提升，这说明a-Fe2O3粉末作为第二相引入的确能够改善超导块材的性能．值得注意的是，a-Fe203掺杂量x=0．1mol％时，不降低临界转变温度（93．5K）的同时临界电流密度Jc可以达到68000A／cm^2，而捕获磁场能够提升到0．15T左右．微观结构观察中发现，伴随着a-Fe203粉末的掺杂，Gd2BaCuO5粒子呈现出更好的分布性且Gd2BaCuO5粒子的粒径从最初的2．19vim降低到1．31μm左右．这可能是引起超导性能改善的重要原因．这些结果对今后进一步提高超导块材GdBa2Cu3O7-δ的各方面性能提供一定的帮助．

英文摘要：

By using top-seeding melt texture growth process, single domain GdBa2 Cu3 O7-δ（Gd123）superconductor bulks doping with the different additions of a-Fe2 O3（x= 0,0. 1,0. 2,0. 4,0. 8mol%） were successfully achieved.The effect with different additions of a-Fe2O3 on the critical current density, the trapping flux and the microstructure, has also been investigated. The result shows that the critical current density Jc and the trapped field have an obvious enhancement with doping a-Fe2O3, which suggested that the samples doping with a-Fe2O3 particles can enhance the performance of the bulk. It was notable that the highest critical current density Jc can reach 68000A/cm2 at zero field and the trapped field can increase to 0.15T with x=0. 1mol% of the a-Fe2 O3 particles. The Gd2 BaCuOs particles in the bulk exhibit more homogenous distribution and the size of Gdz BaCuO5 reduces from 2. 19μm to 1. 31μm, which may lead to the improvement of the superconductivity bulks. The present results are important and helpful for the further enhancement of the performance of Gd123 bulk superconductors.