Electronic and structural properties of Bulk γAl_2O_3

摘要

γ-Al_2O_3 is a defective spinel phase of alumina with cation site vacancies randomly distributed. Its structure and prop- erties are not well understood. There has been long- standing controversy as to whether the cation vacancies are located at the tetrahedral sites or the octahedral sites. Based on an empirical pair potential calculation and first- principles electronic structure studies, we have concluded that cation vacancies are preferentially located at the octa- hedral sites in bulk γ-Al_2O_3. Our calculation shows that the electronic structure of γ-Al_2O_3 differs from that of α-Al_2O_3 in fine details.