Superconductivity in La2Ni2In

We report here the properties of single crystals of ${\mathrm{La}}_{2}{\mathrm{Ni}}_{2}\mathrm{In}$. Electrical resistivity and specific heat measurements concur with the results of density functional theory calculations, finding that ${\mathrm{La}}_{2}{\mathrm{Ni}}_{2}\mathrm{In}$ 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 ${\mathrm{La}}_{2}{\mathrm{Ni}}_{2}\mathrm{In}$ is a dirty type-II superconductor with likely $s$-wave gap symmetry. Nanoclusters of ferromagnetic inclusions significantly affect the subgap states resulting in a nonexponential temperature dependence of the specific heat $C(T)$ at $T\ensuremath{\ll}{T}_{c}$.

我们在此报道了$La_2Ni_2In$单晶的性质。电阻率和比热测量结果与密度泛函理论计算结果一致，发现$La_2Ni_2In$是一种弱关联金属，其中镍的磁性几乎完全被猝灭，仅在态密度上留下了弱的斯托纳增强。在低于0.9 K的温度下观察到超导现象。对最低温度下电阻率、磁化率和比热的磁场和温度依赖性的详细分析表明，$La_2Ni_2In$是一种可能具有s波能隙对称性的脏的第二类超导体。铁磁夹杂物的纳米团簇显著影响亚能隙态，导致在$T\ll T_c$时比热$C(T)$具有非指数温度依赖性。