发表机构
Free Electron Laser Utilization Laboratory, Raja Ramanna Centre for Advanced Technology; Homi Bhabha National Institute; European Organization for Nuclear Research (CERN); School of Studies in Physics, Vikram University; Accelerator Physics and Synchrotrons Utilization Division, Raja Ramanna Centre for Advanced Technology; UGC-DAE Consortium for Scientific Research（拉贾·拉曼纳高级技术中心自由电子激光利用实验室; 霍米·巴哈国家研究所; 欧洲核子研究组织（CERN）; 维克拉姆大学物理研究学院; 拉贾·拉曼纳高级技术中心加速器物理与同步辐射利用司; UGC-DAE科学研究联盟）
机构由 AI 辅助整理，请以论文原文为准。AI 中文总结
本研究通过不同温度下的连续冷加工和退火处理 V$_{0.59}$Ti$_{0.40}$Ce$_{0.01}$ 合金超导体，发现 550°C 中间退火能平衡缺陷产生与相演化，在宽磁场范围内显著提升临界电流密度。
AI 中文摘要
V-Ti 合金超导体的临界电流密度（$J_c$）强烈受钉扎磁通线的微观结构缺陷的尺寸和分布影响。本研究考察了在 550°C 下连续冷加工和退火（SCA）对 V$_{0.59}$Ti$_{0.40}$Ce$_{0.01}$ 合金的微观结构、超导性能和磁通钉扎行为的影响，并与先前报道的在 450°C 和 650°C 下的 SCA 进行了比较。在 550°C 的 SCA 过程中，超导转变温度随连续处理步骤逐渐升高。冷轧至 50% 厚度后的首次退火在所测磁场范围内显著提高了 $J_c$，而后续的 SCA 循环仅带来微小变化。$J_c$ 在宽磁场范围内对磁场的依赖性相对较弱，最终冷加工样品在高达 8.5 T 的磁场下仍具有有限的 $J_c$。钉扎力密度分析表明，在低磁场下晶界主导磁通钉扎，而在较高磁场下位错和 $\beta$-$\alpha'$ 界面成为主要钉扎中心。不同 SCA 温度的比较显示，650°C 提供最高的低场 $J_c$，而 450°C 提供最佳的高场性能。相比之下，550°C 的 SCA 提供了最均衡的磁场依赖性和相对于相应铸态合金的最大 $J_c$ 增强。尽管在高场区域最高的绝对 $J_c$ 是在 450°C 下第三次 SCA 循环后实现的，但在 550°C 下仅首次退火后就获得了相当的值。这些结果表明，550°C 的中间退火温度在缺陷产生、相演化和回复之间提供了有效平衡，从而在宽磁场范围内增强了磁通钉扎。
英文摘要
The critical current density ($J_c$) of V-Ti alloy superconductors is strongly influenced by the size and distribution of microstructural defects that pin magnetic flux lines. In this work, the effect of successive cold working and annealing (SCA) at 550°C on the microstructure, superconducting properties, and flux-pinning behaviour of the V$_{0.59}$Ti$_{0.40}$Ce$_{0.01}$ alloy is investigated and compared with the previously reported SCA at 450 and 650°C. During SCA at 550°C, the superconducting transition temperature increases gradually with successive processing steps. The first annealing after cold rolling to 50% thickness produces a significant enhancement in $J_c$ over the measured field range, whereas subsequent SCA cycles result in only marginal changes. The $J_c$ remains relatively weakly dependent on magnetic field over wide magnetic-field range, and the final cold-worked sample exhibits a finite $J_c$ up to 8.5 T. Pinning force density analysis shows that grain boundaries dominate flux pinning in low magnetic fields, whereas dislocations and $β$-$α'$ interfaces become the dominant pinning centres in higher fields. Comparison of the different SCA temperatures shows that 650°C provides the highest low-field $J_c$, whereas 450°C gives the best high-field performance. In contrast, SCA at 550°C provides most balanced field dependence and the largest enhancement in $J_c$ relative to the corresponding as-cast alloy. Although the highest absolute $J_c$ in the high-field regime is achieved after the third SCA cycle at 450°C, a comparable value is obtained after only the first annealing at 550°C. These results demonstrate that the intermediate annealing temperature of 550°C provides an effective balance between defect generation, phase evolution, and recovery, resulting in enhanced flux pinning over a wide magnetic-field range.
