Heteroepitaxial growth of nanostructured cerium dioxide thin films by MOCVD on a (001) TiO2 substrate

The deposition of epitaxial CeO2 nanostructured thin films on rutile (TiO2) substrates by metal-organic chemical vapor deposition (MOCVD) has been carried out in a wide temperature range. Films have been grown on (001)TiO2 from the Ce(III) 1,1,1,5,5,5-hexafluoro-2,4-pentanedionato diglyme adduct (Ce(hfa)(3)-diglyme). The X-ray diffraction patterns of all samples grown in the 450-750degreesC deposition temperature range point to the formation of <100>-oriented CeO2 films, whereas at higher deposition temperatures (8501050degreesC) all the deposited CeO2 films show <111> texture. fwhm rocking curves values clearly indicate that the texturing of CeO2 crystallites is greatly improved upon increasing the deposition temperature in both cases. Typical pole figure patterns demonstrate a cube-on-cube epitaxial growth in the case of <100>-oriented CeO2 films, whereas <111> -oriented CeO2 films show different in-plane alignments of the crystallites. A possible explanation for textural changes is proposed.