Three independent components of critical current density, one for the H//c axis and the other two for the H//ab plane, have been studied in CaKFe4As4 single crystals. When the magnetic field is applied along the c axis, we observed fish-tail-like peaks in the M-H hysteresis loop, and the magnetization at higher temperatures exceeds that at lower temperatures at high fields. When the field is applied parallel to the ab plane, a dip structure is observed in the M-H hysteresis loop near the self-field. In addition, for the H//ab plane, we succeeded in separately evaluating the large and significantly anisotropic in-plane and out-of-plane Jc. Transmission electron microscopy revealed the presence of planar defects parallel to the ab plane in CaKFe4As4, which have not been observed in any other iron-based superconductors. We discuss the possible relationship between the anomalous Jc behavior and the planar defects.
@article{arxiv.1903.00866,
title = {Large and significantly anisotropic critical current density induced by planar defects in CaKFe4As4 single crystals},
author = {Sunseng Pyon and Ayumu Takahashi and Ivan Veshchunov and Tsuyoshi Tamegai and Shigeyuki Ishida and Akira Iyo and Hiroshi Eisaki and Motoharu Imai and Hideki Abe and Taichi Terashima and Ataru Ichinose},
journal= {arXiv preprint arXiv:1903.00866},
year = {2019}
}
Comments
19 pages, 8 figures + supplemental material 6 pages, 4 figures To be published in Phys. Rev. B