Two-dimensional growth of SrTiO3 thin films on (001) MgO substrates using pulsed laser deposition and reflection high energy electron diffraction

Abstract

Two-dimensional epitaxial growth of SrTiO3 is achieved on MgO, a substrate presenting a large lattice mismatch of 7.9%. In situ reflection high energy electron diffraction (RHEED) is used to monitor and control the growth. An interval deposition technique is implemented to force the two-dimensional growth. It is necessary to deposit a single atomic layer of TiO2 before SrTiO3 to prevent the formation of high energy SrO/MgO interfaces and so allow the film to completely wet the substrate surface. Defect formation is inhibited. The resulting film exhibits a similar surface to the substrate and shows a streaky RHEED pattern.