Superconducting properties of the In-substituted topological crystalline insulator SnTe

Abstract

We report detailed investigations of the properties of a superconductor obtained by substituting In at the Sn site in the topological crystalline insulator (TCI), SnTe. Transport, magnetization, and heat capacity measurements have been performed on crystals of Sn${}_{0.6}$In${}_{0.4}$Te, which is shown to be a bulk superconductor with ${T}_{c}^{\mathrm{onset}}$ at $\ensuremath{\sim}$$4.70(5)$ K and ${T}_{c}^{\mathrm{zero}}$ at $\ensuremath{\sim}$$3.50(5)$ K. The upper and lower critical fields are estimated to be ${\ensuremath{\mu}}_{0}{H}_{c2}(0)=1.42(3)$ T and ${\ensuremath{\mu}}_{0}{H}_{c1}(0)=0.90(3)$ mT, respectively, while $\ensuremath{\kappa}=56.4(8)$ indicates this material is a strongly type-II superconductor.