Epitaxial growth and characterization of Ce1-xZrxO2 thin films

Epitaxial films of mixed Ce1-xZrxO2(001) oxides with x less than or equal t o 0.3 have been grown on SrTiO3(001) by oxygen-plasma-assisted molecular be am epitaxy. The film growth at 600 degrees C is predominantly nucleation an d growth of three-dimensional islands. The films become much smoother after rapid thermal annealing at 700 degrees C for 30 s in the oxygen plasma. Hi gh-energy ion channeling reveals 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 ener gies shows that the oxidation state of both Zr and Ce is +4. Lattice distor tion induced by incorporation of Zr in the CeO2 lattice becomes prevalent f or high doping levels and surface roughen accordingly. (C) 1999 American Va cuum Society. [S0734-2101(99)04303-1].