The V-Ti alloys are promising materials as alternate to the commercial Nb-based superconductors for high current-high magnetic field applications. However, the critical current density (Jc) of these alloys are somewhat low due to their low grain-boundary density. We show here that grain refinement of the V-Ti alloys and enhancement of the Jc can be achieved by the addition of Gd into the system, which precipitates as clusters along the grain boundaries. Both the Jc and the pinning force density (FP) increase with the increasing Gd content up to 1 at. % Gd, where they are more than 20 times higher than those of the parent V0.60Ti0.40 alloy. Introduction of Gd into the system also leads to ferromagnetic (FM) correlations, and the alloys containing more than 0.5 at. % Gd exhibit spontaneous magnetization. In spite of the FM correlations, the superconducting transition temperature increases slightly with Gd-addition.

中文翻译：

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添加Gd的V0.60Ti0.40合金超导体的晶粒细化和临界电流密度的提高


V-Ti 合金是一种很有前途的材料，可以替代商用铌基超导体，用于高电流高磁场应用。然而，由于这些合金的晶界密度较低，其临界电流密度（Jc）较低。我们在此表明​​，通过在系统中添加 Gd 可以细化 V-Ti 合金的晶粒并提高 Jc，Gd 沿晶界以簇状沉淀。随着 Gd 含量增加至 1 at，Jc 和钉扎力密度 (FP) 均增加。 % Gd，比母体 V0.60Ti0.40 合金高 20 倍以上。在系统中引入 Gd 也会导致铁磁 (FM) 相关性，并且含有超过 0.5 at 的合金。 ％Gd表现出自发磁化。尽管存在 FM 相关性，但超导转变温度随着 Gd 的添加而略有增加。