Transmission electron microscopy observation of the interfacial reaction between a metal-organic chemical vapor deposition BaTiO3 thin film and a (100) MgO substrate

Abstract

Cross-sectional and plan-view transmission electron microscopy were used to characterize a BaTiO3 thin film deposited on a (100) MgO single-crystal substrate at 1000 °C. The major observations were as follows: interdiffusion between the film and substrate; a large number of antiphase boundaries in the BaTiO3; a two-phase microstructure in the film composed of perovskite BaTiO3 and a second nonperovskite phase, Ba2MgTi5O13 (2:1:5); and a well-defined orientation relationship between the 2 : 1 : 5 and BaTiO3 phases. We propose a mechanism for the formation of the 2 : 1 : 5 phase based on the similarities between the crystal structure of this phase and the structure of (210) antiphase boundaries in BaTiO3.