A computational study of cation defects in LaGaO3

Static lattice simulation techniques were used to calculate the energetics of intrinsic defect generation, impurity incorporation and cation migration in the perovskite oxide LaGaO3. The calculations indicate that the formation of cation vacancies is energetically favoured over the formation of cation interstitials; expressions for the generation energies of lanthanum vacancies and of gallium vacancies are derived for several Brouwer regimes. Divalent and trivalent impurity cations with ionic radii smaller than 0.8 Å in sixfold coordination are predicted to substitute preferentially for Ga3+. The migration energies of both native and impurity cations were determined. Simple models describing the migration energetics are proposed.