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 pu lsed laser ablation (PLA) on r-cut (1 (1) over bar 02) Al2O3 substrates and evaluated the effects of predeposition annealing conditions of Al2O3 and f ilm thickness of CeO2, The annealing of Al2O3 substrates improves the smoot hness of the surface and performing this in high vacuum leads to better cry stallinity and orientation of deposited CeO2 films compared to those anneal ed in oxygen. A critical value of the film thickness was found beyond which the surface roughness increases abruptly. Atomic force microscopy (AFM) st udy showed that the surface of CeO2 films is characterized by a mazelike pa ttern. Increasing the film thickness leads to the formation of larger islan ds which cause the increase in the surface roughness of the films. The area l density and height of these islands increased with film thickness.