Orientation and Crystal Structure of SrTiO3 Thin Films Prepared by Pulsed Laser Deposition

Publisher Website
Google Scholar
Abstract
SrTiO3 thin films are grown on MgO(001) substrates at growth temperatures between 600-800° C and at oxygen pressures between 10-1-10-6 Torr. The initial stage of growth is controlled by graphoepitaxy with a cube-on-cube orientation. In the growth temperature range from 600° C to 740° C, graphoepitaxy occurs only at 10-6 Torr or 740° C. At 10-6 Torr the internal and kinetic energies of the evaporated particles contribute to the surface mobility necessary for graphoepitaxy, while at 740° C heat energy assures surface migration. However, at 800° C, the orientation changes to (111) with increasing thickness. This is because the dominant factor of film growth changes to the formation of a close-packed surface as the growth front gets farther from the substrate surface.