Hetero-Epitaxial Growth of CeO2 Films on MgO Substrates

Abstract

High quality hetero-epitaxial CeO2 films are grown on MgO substrates using BaSnO3 buffer layers. CeO2 films and BaSnO3 buffer layers are grown by a pulsed laser deposition method. It is found that the crystallinity of the CeO2 films directly grown on MgO substrates is quite poor. However when we grow CeO2 films on MgO substrates with a BaSnO3 buffer layer, the crystallinity of CeO2 films is improved from that of the directly grown CeO2 films. Also the estimated in-plane crystallinity (δφ) of the CeO2 films on the BaSnO3 buffer layers is much improved by the introduction of the buffer layers. One of the reasons for high quality CeO2 films are grown on MgO substrates by the introduction of BaSnO3 buffer layers is the lattice matching between the CeO2 films and the MgO substrates. The CeO2 films grow in a 45° rotated mode to the BaSnO3 buffered MgO substrates, then the lattice mismatch between the sublattice of the CeO2 films and the MgO substrates is calculated to be 9.3%, while that of the CeO2 films on MgO substrates in a cube on cube mode is over 25%.