Grain alignment is a key factor that determines the performance of a superconducting bulk. In this study, the spark plasma texturing (SPT) technique was used to fabricate a CaKFe4As4 superconducting bulk. X-ray diffraction and electron backscatter diffraction revealed that the c-axes of the CaKFe4As4 grains in the SPT bulk are aligned, demonstrating that the SPT technique is effective in achieving c-axis texture. In addition, chemical composition analysis showed that oxide impurities, which affect the grain boundary characteristics that determine the inter-grain critical current density (Jc), are randomly distributed in the SPT bulk. Magnetization measurements showed high Jc values of the SPT bulk, reaching 127 kA cm−2 and 26 kA cm−2 at 4.2 K under a self-field and magnetic field of 5 T, respectively. These results suggest that the SPT technique is a promising approach for obtaining a high-performance superconducting bulk material for high-field applications.
@article{arxiv.2403.19984,
title = {Synthesis of $c$-axis textured CaKFe$_4$As$_4$ superconducting bulk via spark plasma texturing technique},
author = {Shigeyuki Ishida and Yoshihisa Kamiya and Yoshinori Tsuchiya and Pavan Kumar Naik Sugali and Yasunori Mawatari and Akira Iyo and Yoshiyuki Yoshida and Hiroshi Eisaki and Kenji Kawashima and Hiraku Ogino},
journal= {arXiv preprint arXiv:2403.19984},
year = {2024}
}