Superconductivity induced by In substitution into the topological crystalline insulator Pb0.5Sn0.5Te

Indium substitution turns the topological crystalline insulator (TCI) Pb0.5Sn0.5Te into a possible topological superconductor. To investigate the effect of the indium concentration on the crystal structure and superconducting properties of (Pb0.5Sn0.5)(1-x)InxTe, we have grown high-quality single crystals using a modified floating-zone method and have performed systematic studies for indium content in the range 0 <= x <= 0.35. We find that the single crystals retain the rocksalt structure up to the solubility limit of indium (x similar to 0.30). Experimental dependencies of the superconducting transition temperature (T-c) and the upper critical magnetic field (H-c2) on the indium content x have been measured. The maximum T-c is determined to be 4.7 K at x = 0.30, with mu H-0(c2)(T = 0) approximate to 5 T.