Applicability of the vortex-glass model for the single crystal Tl0.4K0.41Fe1.71Se2**Project supported by the National Natural Science Foundation of China (Grant Nos. 11404002, 11404003, and 11074001) and the Scientific Research Foundation for the Returned Overseas Chinese Scholars, and the “211 Project” of Anhui University, China (Grant No. J01001319-J10113190007).

Abstract

We measure the current–voltage (I–V) characteristics for the single crystal of Tl0.4K0.41Fe1.71Se2 with the superconducting transition temperature (TC) around 30.5 K, under a 10 T magnetic field applied perpendicular and parallel to the ab plane. We find that the shapes of the I–V isotherms are very different from the description by the vortex-glass (VG) model. Combining theoretical calculations and analysis of the ρH⊥ab–T and ρH∥ab–T data, we give an explicit discussion over the suitability of the VG model for the A0.8Fe2Se2 superconductors, and point out the possibility of the material acting as a convenient platform for re-examination and further study of the complex vortex behaviors in the layered superconductors.