Molecular Layer Epitaxy of Perovskite-Based Oxides by Laser MBE

Abstract

Molecular layer epitaxy and the topmost surface structure in laser MBE of perovskite and other related oxides were investigated by in situ RHEED, in situ angle-resolved XPS (ARXPS) and ex situ co-axial ISS (CAICISS) analyses. Two-dimensional epitaxial growths of SrTiO3 (001) and BaCuO2(001) on SrTiO3(001) substrate were achieved by optimizing the growth conditions. Periodicities of RHEED oscillation corresponded well to the growth of a repeating unit cell (molecular layer). ARXPS and CAICISS spectra revealed that (Sr-0) atomic plane came at the top of SrTiO3(001) film growing on SrTiO3 (001) substrate with (Ti-O) atomic plane on the top. This indicates the structural conversion of the topmost atomic layer from TiO2 to SrO occurred during the SrTiO3 homoepitaxial growth.