Layer-by-layer and pseudo-two-dimensional growth modes for heteroepitaxial BaTiO3 films by exploiting kinetic limitations

Abstract

Pulsed laser deposition has enabled formation of highly oxidized and strained BaTiO3 films on SrTiO3 substrates in a layer-by-layer growth mode to thicknesses of 125nm. Balancing thermodynamics and diffusion lengths enables controlled growth at the higher oxygen pressures required. Growth above 800°C produces an array of uniform pseudo-two-dimensional islands on single-step terraces which are independent of film thickness and correlated with threading dislocations. Control over growth modes is enabled by the manipulation of diffusion lengths and produces films with morphologies with broad applicability for fabrication of high-quality oxide films and self-assembled nanostructures.