Electronic structure of superconducting non-oxide perovskite MgCNi3

The recently discovered superconductor MgCNi3 crystallizes in the classical cubic perovskite structure. The electronic structures of the MgCNi3-xMx (M = Co, Cu; x = 0, 0.5, 1.0) system have been calculated using the self-consistent tight-binding linear muffin-tin orbital method. The calculations showed that the Fermi level for MgCNi3 is located in the slope descending from a sharp peak originating from d states of Ni atoms. Electron (Cu) and hole (Co) doping of MgCNi3 reconstructs its band structure but does not lead to magnetic order.