Transmission electron microscopy of epitaxial SrTiO 3 films on LaAlO 3 substrates

Abstract Three different epitaxial (001) SrTiO 3 films deposited on (110) rhombohedral LaAlO 3 substrates by rf sputtering, have been characterised using transmission electron microscopy (TEM). The films exhibited different columnar subgrain morphologies with column widths ranging from 7 to 19 nm. Slow cooling in an O 2 ambient and in situ annealing at elevated temperature improved the films dielectric tunability and this could be correlated to more narrow column dimensions.