摘要
以定向反应合成的 YBa_2Cu_3O_x 为原料,用加大成型压力——高温熔化——三段热处理工艺,可将 YBa_2Cu_3O_x 体材料的 J_c 提高到 713 A/cm^2(78 K);讨论了晶粒间界的空隙,微区化学组成不均匀性,高温熔化及凝固过程对 J_c的影响。结果表明,采用较大压力成型,高温熔化工艺,提高碳酸盐分解率,有助于提高临界电流密度J_c。
Superconducting YBa_2Cu_3O_x synthesized through directional reaction were usedas test samples. The critical current density of bulk YBa_2Cu_3O_x supercon-ductor, J_c,was found up to 713 A/cm^2(78K) after increasing pellet--formingpressure, high-temperature melting and, finally, a 3-step heat treatment. Theinfluences of the micro--porosity between grain boundaries, the inhomogeneityof chemical composition,high -temperature melting and solidification processon J. are discussed briefly. The results show that higher pelletforming press-ure,high--temperature melting and raised dissociation rate of barium carbonateare he1pful to enhancing J_c.
关键词
超导材料
液氮温区
临界电流密度
superconducting material
critical current density
melting
