Growth and structure of epitaxial CeO2 films on yttria-stabilized ZrO2

Thirty to a hundred-nm thick epitaxial CeO2 layers are grown on YSZ (100), (110) and (111) surfaces of yttria-stabilized ZrO2 (YSZ) by electron beam evaporation of Ce in oxygen at reduced pressure. Their growth, structure and thermal stability are studied with several bulk and surface sensitive techniques including Rutherford backscattering spectrometry, cross-sectional high resolution electron microscopy, low energy electron diffraction and low energy reflection electron microscopy. Excellent epitaxy is obtained on all YSZ surfaces at a growth temperature of 750 K. The surfaces of films grown on (111)-oriented substrates are flat, whereas those on the other substrates are faceted into small (111) planes. The grain sizes in the films are in the 10 nm range and smaller.