LaCrO3 heteroepitaxy on SrTiO3(001) by molecular beam epitaxy

Stoichiometric, epitaxial LaCrO3 films have been grown on SrTiO3(001) by molecular beam epitaxy using O-2 as the oxidant. Films grew in a layer-by-layer fashion, giving rise to coherently strained, structurally excellent films and surfaces which preserve the step-terrace structure of the substrate. The critical thickness is in excess of 500 angstrom. Cr(III) near the surface is easily oxidized to Cr(V) upon exposure to atomic oxygen and reduction back to Cr(III) is readily achieved by vacuum annealing, resulting in tunability of the charge state at the B-site cation. (C) 2011 American Institute of Physics. [doi:10.1063/1.3624473]