Structural properties of SrO thin films grown by molecular beam epitaxy on LaAlO3 substrates

Abstract

SrO films were grown on LaAlO3 substrates by molecular beam epitaxy and characterized using reflection high-energy electron diffraction (RHEED) and x-ray diffraction (XRD). The evolution of the RHEED pattern is discussed as a function of film thickness. 500Å thick SrO films were relaxed and exhibited RHEED patterns indicative of an atomically smooth surface having uniform terrace heights. Films had the epitaxial relationship (001)SrO‖(001)LaAlO3; [010]SrO‖[110]LaAlO3. This 45° in-plane rotation minimizes mismatch and leads to films of high crystalline quality, as verified by Kikuchi lines in the RHEED patterns and narrow rocking curves of the (002) XRD peak.