PNNL

Abstract

Epitaxial films have been grown on SrTiO3(001) by oxygen-plasma-assisted molecular beam epitaxy. The film growth at 600 degrees C is predominantly nucleation and growth of 3-D islands. The films become much smoother after rapid thermal annealing at 700 degrees C for 30 seconds in the oxygen plasma. High-energy ion channeling reavelas that Zr atoms substitutionally incorporate at cation sites in the CeO2 lattice for all doping levels, leading to Ce1-xZrxO2 solid solutions. Analysis of Zr 3d and Ce 3d core-level binding energies shows that the oxidation state of both Zr and Ce is +4. Lattice distortion induced by incorporation of Zr in the CeO2 lattice beomes prevalent for high doping levels, and surfaces roughen accordingly.