Band structure and thermoelectric properties of type-III barium clathrates

Abstract

The electronic structure of type-III Ba clathrates was calculated by using a full-potential linearized augmented plane-wave (FLAPW) method. In the calculation of Ba₆Al₄Si₂₁ a virtual crystal approximation was used. The calculated band structure shows that Ba₆Al₄Si₂₁ is an intrinsic semiconductor with an indirect gap. The top of the valence band is at the Gamma point and the bottom of the conduction band is on the Lambda axis. The thermoelectric properties are calculated by using the calculated electronic states