Native point defects in yttrium aluminum garnet were studied within the framework of the pair-potential approximation, coupled with a shell-model description of lattice ions. A new set of potential parameters was obtained for the perfect lattice. These parameters reproduced the structural, elastic and dielectric constants very well. The calculated formation energies for native defects suggested that antisite disorder was preferred to Frenkel- or Schottky-like disorder. The calculated values of the distortion, that was caused by an antisite Y atom which was substituted at an Al site in the lattice, were in excellent agreement with extended X-ray absorption fine-structure measurements. In non-stoichiometric samples, the calculated reaction energies indicated that excess Y2O3 or Al2O3 was most likely to be accommodated by the formation of antisites rather than vacancies.

Atomistic Modelling of Native Point Defects in Yttrium Aluminum Garnet Crystals. M.M.Kuklja, R.Pandey: Journal of the American Ceramic Society, 1999, 82[10], 2881-6