Superconductivity in La$_2$Ni$_2$In

Abstract

We report here the properties of single crystals of La2Ni2In. Electrical resistivity and specific heat measurements concur with the results of Density Functional Theory (DFT) calculations, finding that La2Ni2In is a weakly correlated metal, where the Ni magnetism is almost completely quenched, leaving only a weak Stoner enhancement of the density of states. Superconductivity is observed at temperatures below 0.9 K. A detailed analysis of the field and temperature dependencies of the resistivity, magnetic susceptibility, and specific heat at the lowest temperatures reveals that La2Ni2In is a dirty type-II superconductor with likely s-wave gap symmetry. Nanoclusters of ferromagnetic inclusions significantly affect the subgap states resulting in a non-exponential temperature dependence of the specific heat C(T ) at T Tc.