A study of the semi-coherent ceramic SrTiO3/SrZrO3 interface by firstprinciples DFT calculations

First-principles electronic-structure calculations based on the density functional theory and by means of the mixed-basis pseudopotential method were carried out for SrTiO3/SrZrO3 (001) interfaces., SrZrO3 can be grown epitaxially on a (001)-oriented surface of a SrTiO3 single crystal with a cube-on-cube orientation relationship. The lattice mismatch of 5% between the two perovskites is accommodated by the formation of a square network of misfit dislocations at the interface. In order to estimate the effect of these dislocations on the interface stability with respect to cleavage, we developed a theoretical model for semi-coherent interfaces in ceramics, which is inspired by Recent work of Benedek et al. for intermetallics. In this approach the semi-coherent interface with an arbitrary mi sfit is described as a combination of bits of coherent interfaces, which mimic the local structures present in the coherent regions and at the cores of misfit dislocations. We present results for different geometrical translation states and chemical interface terminations, and we discuss the results in relation to experimental observations by Ernst et al. using high-resolution transmission electron microscopy.