Electronic properties of superconductingLuNi2B2C and related boride carbide phases

Band properties of the quaternary superconductor ${\mathrm{LuNi}}_2$ ${\mathrm{B}}_2$C (${\mathit{T}}_{\mathit{c}}$≊17 K) and related intermetallic phases (including, for example, LuNiBC and ${\mathrm{YNi}}_2$ ${\mathrm{B}}_2$C) have been calculated in the local-density approximation via the linear augmented-plane-wave method. The results feature a density-of-states peak near the top of nearly filled Ni(3d) bands, with only modest B and C orbital admixture. The calculated ${\mathrm{LuNi}}_2$ ${\mathrm{B}}_2$C bands suggest that these interesting boride carbide phases represent a family of conventional (rather than high-${\mathit{T}}_{\mathit{c}}$) superconductors.