LaCrO3 heteroepitaxy on SrTiO3(001) by molecular beam epitaxy

TL;DR

This paper reports the successful growth of high-quality LaCrO3 epitaxial films on SrTiO3(001) substrates via molecular beam epitaxy, highlighting the growth process, structural quality, and oxidation behavior.

Contribution

It demonstrates the layer-by-layer growth of LaCrO3 films with excellent structural quality and explores oxidation effects and recovery methods.

Findings

Films exhibit layer-by-layer growth with preserved substrate step-terrace structure.

Critical thickness of films exceeds 500 Å.

Surface Cr(III) can oxidize to Cr(V), forming disordered phases, reversible by vacuum annealing.

Abstract

Stoichiometric, epitaxial LaCrO3 films have been grown on TiO2-terminated SrTiO3(001) substrates by molecular beam epitaxy using O2 as the oxidant. Film growth occurred in a layer-by-layer fashion, giving rise to structurally excellent films and surfaces which preserve the step-terrace structure of the substrate. The critical thickness is in excess of 500 {\AA}. Near-surface Cr(III) is highly susceptible to further oxidation to Cr(V), leading to the formation of a disordered phase upon exposure to atomic oxygen. Recovery of the original epitaxial LaCrO3 phase is readily achieved by vacuum annealing.