Epitaxial solid-solution films of immiscible MgO and CaO

Abstract

Metastable solid solutions in the MgO-CaO system grow readily on MgO at 300 °C by molecular beam epitaxy. The epitaxy displays both the reflection high-energy electron diffraction oscillations characteristic of layer-by-layer growth and the lattice rotations which have been related to island nucleation. Mg1−xCaxO solid solutions grow despite a larger miscibility gap than in any system for which epitaxial solid solutions have been grown. Epitaxial quenching of nonequilibrium solid solutions is possible because of the very low growth temperatures for rock-salt oxides.