Atomistic simulation of grain boundaries in alumina

Results of theoretical calculations of equilibrium structures of grain boundaries in alpha-Al2O3 are presented, The simulations are based on an atomistic model involving lattice statics, molecular dynamics, and Monte Carlo in which empirical and quantum mechanically derived interionic pair potentials are employed. Calculations carried out on the basis of empirical potentials indicate that trivalent impurities Y3+, Fe3+, and La3+ segregate to the (10 (1) over bar 4) grain boundary. The energy of segregation is approximately quadratically dependent on the the differences in volume between the dopant and the host ion.