Evolution of texture of CeO2 thin film buffer layers prepared by ion-assisted deposition

Evolution of texture in CeO₂ thin films was studied using biased magnetron sputtering and ion beam assisted magnetron sputtering. Films deposited onto polycrystalline Hastelloy metal substrates by biased magnetron sputtering develop preferential (002) growth as the energy of the ions is increased from zero to above 100 eV. For ion beam assisted magnetron sputtering (magnetron IBAD), with the ion beam directed at 55° to the substrate normal, the evolution of biaxial alignment is controlled by the ion beam energy and the ion/atom arrival rate ratio. Ion beam energies >200 eV and ion/atom ratios >0.3 lead to perfect biaxial alignment with one pole aligned along the ion beam direction. Epitaxial growth of CeO₂ films was observed for MgO(001) substrates at 750°C without any ion assistance, and on yttria-stabilised zirconia (001) buffer layers at room temperature and a bias of −80 V.