Low energy ion beam assisted deposition of biaxially aligned YSZ and CeO2/YSZ films on r-plane sapphire

(001) oriented yttria-stabilized zirconia (YSZ) and CeO2/YSZ multilayer films with high in-plane biaxial texture have been deposited on an r-plane sapphire substrate by ion beam assisted deposition (IBAD) at ambient temperature. The optimal in-plane texture, whose full width at half maximum (FWHM) of X-ray (111) φ-scan peak were 15° and 12° for YSZ and CeO2/YSZ films respectively, could be obtained. Monte Carlo simulation results suggest that the divergence of incident bombarding ion beam is expected to have strong influence on film in-plane biaxial texture. The effect of the collimation of incident bombarding ion beam on the formation of high in-plane biaxial texture was demonstrated under certain IBAD conditions. The atomic force microscope(AFM) images indicated that the small-grained, smooth and continuous film structure of the CeO2 film is more favorable for the in-plane biaxial texture development than the large-grained and rough structure of the YSZ film.