Effect of Precursor Powder on the Solidification Microstructure and Superconducting Properties of Superconductors: A Review

The solidification process is crucial for preparing high-performance superconductors and is strongly dependent on the characteristics of the starting powder, including particle size, morphology, and phase purity. This review concisely examines the study on four key superconductors: REBCO, Bi-2212, FeSeTe, and MgB2. In REBCO, additives such as CeO2, Pt, or BaO2 powder can refine the RE-211 phase. In Bi-2212, Pb doping stabilizes the high-Tc phase. For FeSeTe, doping with F or Co modifies phase separation and introduces Δκ pinning. Meanwhile, in MgB2, the incorporation of SiC nanoparticles powder generates effective pinning centers. Concurrently, processing conditions exert a decisive influence on the final microstructure, as demonstrated by the TSMG/TSIG route in REBCO, partial melting parameters for Bi-2212, specific cooling protocols and thermal treatments for FeSeTe, and optimized sintering and post-annealing processes for MgB2. Future research directions should prioritize fundamental understanding of phase separation mechanisms during powder processing, development of multi-component doping strategies for powder modification, and advancement of scalable powder processing routes for practical conductor architectures.