Structural stability and electronic properties in Al2O3–Cr2O3 mixed crystal

Abstract

Structural stability and electronic properties of a corundum (Al1−xCrx)2O3 structure over the whole Cr composition are investigated by means of the full-potential linearized augmented plane-wave method within the local-spin-density approximation (LSDA)+U. Calculated results predict that ordered and disordered states are energetically less favorable with respect to a phase separation, and that interatomic distances do not change over the whole Cr composition, where the Cr–O distance is always larger than the Al–O distance. An antibonding Cr 3d–O 2p hybridization leads to the phase-separated-type phase stability and the structural property.