Superconducting critical fields of K$_{0.8}$Fe$_{2}$Se$_2$ single crystal

M. I. Tsindlekht; I. Felner; M. Zhang; A. F. Wang; X. H. Chen

paper

Superconducting critical fields of K $_{0.8}$ Fe $_{2}$ Se $_{2}$ single crystal

arXiv:1105.1065

Abstract

We report the results of an experimental study of dc and low frequencies magnetic properties of K $_{0.8}$ Fe $_{2}$ Se $_{2}$ single crystal when the dc magnetic field is applied parallel to the $ab$ plane. From the data obtained, we deduce the full H-T phase diagram which consists of all three H $_{c 1}$ (T), H $_{c 2} (T)$ and H $_{c 3} (T)$ critical magnetic field plots. The two H $_{c 1}$ (T) and H $_{c 2}$ (T) curves were obtained from dc magnetic measurements, whereas the surface critical field H $_{c 3}$ (T) line was extracted by ac susceptibility studies. It appears that near T $_{c}$ , the H $_{c 3}$ (T)/H $_{c 2}$ (T) ratio is $\approx 4.4$ which is much larger than expected.

4 pages, 6 figures

Superconducting critical fields of K0.8​Fe2​Se2​ single crystal

Abstract

Superconducting critical fields of K $_{0.8}$ Fe $_{2}$ Se $_{2}$ single crystal