We have established a simple process that allows for the one-step synthesis of K xFe 2-ySe 2 single crystals, which exhibit high critical current density J c. The post annealing and quenching technique has improved the homogeneity of as-grown crystals, resulting in full shielding of the external magnetic field. The quenched crystals show a superconducting transition at T c onset=32.9 K and T c zero=32.1 K. The upper critical fields μ 0 H 02 (0) for Hab and Hc are estimated to be ∼206 and ∼50 T, respectively. The critical current densities J c for Hab and Hc reach as high as 1.0×10 5 and 3.4×10 4 A/cm 2 at 5 K. Furthermore, J c exhibits a high field performance and a significantly weak temperature dependence up to 5 T, suggesting strong pinning. These results demonstrate that K xFe 2-ySe 2 would be a promising candidate material for practical applications.
ASJC Scopus subject areas
- Physics and Astronomy(all)