Structural properties of strained epitaxial La1+δCrO3 thin films

Epitaxially strained La1+delta CrO3 (LCO) thin films, with delta ranging between -0.25 (Cr-rich) and 0.25 (La-rich), were grown on SrTiO3(001) substrates by solid-source molecular beam epitaxy. The effect of the cationic-stoichiometry deviation (delta) on the structural properties (surface structure, morphology, terminations, and unit-cell parameters) is reported. Whereas deviation from stoichiometry does not significantly affect the structural quality (all films keep a perovskite structure, are epitaxial, atomically flat, fully strained, and present mosaicity below 0.1 degrees); increasing vertical bar delta vertical bar leads to an increase of the out-of-plane lattice parameter and of the unit-cell volume. These results are of importance for further studies on structure-property relationships in the view to build enhanced LCO-based devices. Published by the AVS.