纳米粒子掺杂是在REBCO高温超导体内引入有效磁通钉扎中心的实用方法，而磁性纳米粒子可以在超导体内表现出更深的磁通势阱和更强的磁通钉扎能力。本研究拟利用顶部籽晶熔渗生长（TSIG）方法制备NiFe2O4和BiFeO3磁性纳米粒子掺杂的单畴YBCO超导块材。研究磁性掺杂相与YBCO中物相的作用规律、磁性粒子在Y123基体中的分布规律，阐明磁性纳米粒子与YBCO单畴块材的复合机制。研究磁性纳米粒子掺杂对YBCO超导块材的显微结构、捕获磁通、磁悬浮力、超导转变温度及临界电流密度的影响规律，阐明磁性钉扎中心的作用机制，为进一步揭示高温超导体的磁通钉扎机理奠定基础。同时利用BiFeO3掺杂探索一种在YBCO超导体内引入磁性及YBi2411多源纳米钉扎中心的新方法，为发展制备高质量超导块材提供新思路。本研究对提高REBCO超导块材的磁通钉扎能力，推动其在超导磁体、磁悬浮系统等领域中的应用有重要的意义。

Addition of nanoparticles is a practical method to introduce effective flux pinning centers in REBCO high temperature superconductors, while the magnetic nanoparticles, which form much deeper potential wells than the other nanophase inclusions, can exhibit much enhanced flux pinning force in superconductors. In this project, we propose to conduct a study on the addition of magnetic nanoparticles (NiFe2O4 and BiFeO3) in single-domain YBCO bulk superconductors by employing a top-seeded infiltration and growth (TSIG) technique. The interactions of the magnetic dopants with the phases in YBCO and the final distribution of the magnetic particles in Y123 matrix will be identified for elucidating the composite mechanism of the magnetic nanoparticles with the single-domain YBCO bulk. The influence of the magnetic nanoparticle doping on the microstructure, trapped field, levitation force, superconducting transition temperature and critical current density of the YBCO bulk superconductors will be investigated, and the pinning mechanism of the magnetic nanoparticles in YBCO samples will be elucidated for further understanding of the flux pinning mechanism in high temperature superconductors. Moreover, a novel method for introducing multi-source pinning centers of magnetic and YBi2411 nanoparticles will be explored by using the addition of BiFeO3 nanoparticles, which provides a new idea for fabricating high quality bulk superconductors. The study of this project is important for enhancing the flux pinning force of REBCO bulk superconductors and promoting their applications in the fields of superconducting magnet and maglev systems.