Optimizing the superconducting transition temperature and upper critical field of Sn(1-x)In(x)Te

Sn(1-x)In(x)Te is a possible candidate for topological superconductivity. Previous work has shown that substitution of In for Sn in the topological crystalline insulator SnTe results in superconductivity, with the transition temperature, Tc, growing with In concentration. We have performed a systematic investigation of Sn(1-x)In(x)Te for a broad range of x, synthesizing single crystals (by a modified floating zone method) as well as polycrystalline samples. The samples have been characterized by x-ray diffraction, resistivity, and magnetization. For the single crystals, the maximum Tc is obtained at x=0.45 with a value of of 4.5 K, as determined by the onset of diamagnetism.