Epitaxial Solid-Solution Films of Immiscible MgO and CaO

Abstract

AbstractMetastable solid-solutions in the MgO-CaO system grow readily on MgO at 300°C by molecular beam epitaxy. We observe RHEED oscillations indicating a layer-by-layer growth mode; in-plane orientation can be described by the Matthews theory of island rotations. Although some films start to unmix at 500°C, others have been observed to be stable up to 900°C. The Mgl-xCaxO solid solutions grow despite a larger miscibility gap in this system than in any system for which epitaxial solid solutions have been grown. We describe attempts to use these materials as adjustable-lattice constant epitaxial building blocks