An investigation was made of the migration of La3+ and Sr2+ by an A-site vacancy mechanism in La1-xSrxMnO3. Ab initio calculations determined migration barriers of 2.96 and 2.42eV, for La3+ and Sr2+, respectively, and that repulsion between Sr2+and VA was well-described by a screened electrostatic potential of the form E(eV) = 2.8exp(-0.2r)/r, (r being the separation in Å). Using these results to parameterize kinetic Monte Carlo and analytical calculations for diffusion coefficients good agreement was found with experimental observations of A-site diffusivity in other perovskites. These results were used to analyze the tendency for Sr2+ to de-mix kinetically.

A-Site Diffusion in La1-xSrxMnO3: ab initio and Kinetic Monte Carlo Calculations. B.Puchala, Y.L.Lee, D.Morgan: Journal of the Electrochemical Society, 2013, 160[8], 877-82