Interfacial strain defines the self-organization of epitaxial MoO2 flakes and porous films on sapphire: experiments and modelling

The epitaxy of MoO2 on c-plane sapphire substrates is examined. A theoretical approach, based on density functional theory calculations of the strain energy, allowed to predict the preferred layer/substrate epitaxial relationships. To test the results of these calculations, MoO2/(0 0 1) Al2O3 heterostructures were grown using the chemically-driven isothermal close space vapour transport technique. At the early stages of the growth, two kinds of...