Influences of Epitaxial Strain and Volume on BaTiO3: Ab Initio Total Energy Calculation

Abstract

Using an ab initio total energy calculations based on density functional theory (DFT), out-of-plane c-axis strain is found to be highly oriented to BaTiO3 under large in-plane a-axis compressive strain (substrate). We predict that the lower out-of-plane c-axis strain (1.7%) is favorable to be the most stable for BaTiO3 under −1% (3.9 Å) of the in-plane a-axis compressive strain. Meanwhile, BaTiO3 under more than −3.6% (3.8 Å) of in-plane a-axis compressive strain is suggested to be most stable for higher out-of-plane c-axis strain (11.8%). Therefore, the calculated result based on DFT is accurate in relation to the experimental work reported in literature. This finding is supported by the influences of strain determined based on the calculated electronic and optical properties of BaTiO3.