Effect of Te doping on the structure and superconductivity of K0.8Fe2Se2-zTez single crystals
M. T. Li, W. P. Liu, and C. T. Lin
We report the structure, transport, and magnetic properties of KxFe2−ySe2−zTez single crystals grown by optical floating zone technique. The phase separation phenomena were observed in the Te-doped samples. With increasing Te doping level, the c-axis lattice parameter expands for both insulating/semiconducting and superconducting phases. The critical current density was estimated to be ≈103–104 A/cm2 for the all doped samples. The capability of carrying superconducting current is reduced towards high magnetic field with increase of Te doping.