Electronic structure of Ba(Sn,Sb)O3: Absence of superconductivity

Abstract

The electronic structures of ${\mathrm{BaSnO}}_3$, ${\mathrm{BaSbO}}_3$, and ${\mathrm{BaPbO}}_3$, calculated using an extended general-potential linearized augmented-plane-wave method, are reported. The electronic structures of ${\mathrm{BaSnO}}_3$ and its 6s analog ${\mathrm{BaPbO}}_3$ are found to be very different, explaining the absence of superconductivity in the Ba(Sn,Sb)${\mathrm{O}}_3$ system. These differences are explained by a combination of the relativistic lowering of the 6s states and ion-size effects. Muffin-tin-approximation augmented-plane-wave calculations for ${\mathrm{BaSnO}}_3$ are also reported and the utility of the muffin-tin approximation for this and similar materials is discussed in terms of the differences between the two sets of calculations.