We investigate the fishtail effect, critical current density (Jc) and vortex dynamics in LiFeAs single crystals. The sample exhibits a second peak (SP) in the magnetization loop only with the field ∣∣ c-axis. We calculate a reasonably high Jc, however, values are lower than in 'Ba-122' and '1111'-type FeAs-compounds. Magnetic relaxation data imply a strong pinning which appears not to be due to conventional defects. Instead, its behavior is similar to that of the triplet superconductor Sr2RuO4. Our data suggest that the origin of the SP may be related to a vortex lattice phase transition. We have constructed the vortex phase diagram for LiFeAs on the field-temperature plane.
Cite
@article{arxiv.1009.4896,
title = {Fishtail effect and vortex dynamics in LiFeAs single crystals},
author = {A. K. Pramanik and L. Harnagea and C. Nacke and A. U. B. Wolter and S. Wurmehl and V. Kataev and B. Büchner},
journal= {arXiv preprint arXiv:1009.4896},
year = {2015}
}