Phase stability and interfacial structures in the SrO-SrTiO3 system

摘要

The phase stability of the subsolidus region in the composition regime SrO-SrTiO3 has been studied using a combination of atomistic computer simulation techniques and high-resolution electron microscopy (HREM). Both predictions from atomistic calculations and HREM observations suggest that at low concentrations (less than 50mol% excess SrO), strontium-rich nonstoichiometry is accommodated by formation of a specific Ruddlesden-Popper defect phase (Sr3Ti2O7) With overall composition maintained by a coherent intergrowth of Sr3Ti2O7 and SrTiO3 phases. A model is proposed for the atomic structure of the Sr3Ti2O7-rSrTiO(3) interface.