An insight to the role of Cr in the process of intrinsic point defects in α-Al2O3

Abstract

Cr is a commonly existing impurity in α-Al₂O₃, and thus the role of Cr in the process of intrinsic point defects in α-Al₂O₃ has been studied based on first-principle calculations. The results show that Cr has significant influence on the formation, charge state, relative stability and equilibrium configuration of isolated intrinsic point defects in α-Al₂O₃, resulting in the variation of defect process. Specifically, depending on the O-condition, the possible defect types, the dominant defects and the defect formation energies will be altered in α-Al₂O₃ after Cr doping. Generally speaking, Cr is favorable for the formation of Schottky defects, Frenkel defects and antisite pairs, giving a different insight to the defect process in α-Al₂O₃.