γ-Alumina: a single-crystal X-ray diffraction study

Abstract

The structure of γ-alumina (Al21+1/3◊2+2/3O32) crystals obtained as a product of a corrosion reaction between β-sialon and steel was refined in the space group Fd-3m. The oxygen sublattice is fully occupied. The refined occupancy parameters are 0.83(3), 0.818(13), 0.066(14) and 0.044(18) for Al ions in 8a, 16d, 16c and 48f positions, respectively. The Al ions are distributed over octahedral and tetrahedral sites ina 63:37 ratio, with 6% of all Al ions occupying non-spinelpositions