Studies on the surface morphology and orientation of CeO2 films deposited by pulsed laser ablation

We studied the surface morphology and orientation of CeO2 films grown by pulsed laser ablation (PLA) on r-cut (1 (1) over bar 02) Al2O3 substrates and evaluated the effects of predeposition annealing conditions of Al2O3 and film thickness of CeO2, The annealing of Al2O3 substrates improves the smoothness of the surface and performing this in high vacuum leads to better crystallinity and orientation of deposited CeO2 films compared to those annealed in oxygen. A critical value of the film thickness was found beyond which the surface roughness increases abruptly. Atomic force microscopy (AFM) study showed that the surface of CeO2 films is characterized by a mazelike pattern. Increasing the film thickness leads to the formation of larger islands which cause the increase in the surface roughness of the films. The areal density and height of these islands increased with film thickness.