Role of substrate surface morphology on the epitaxial growth behavior of cerium oxide films prepared by chemical solution deposition

Abstract

CeO₂ films were prepared by chemical solution deposition on Ni–5 at% W substrates with special surface morphologies. The special morphologies of the NiW substrates including pores and grooves could be obtained by an electrochemical etching process. The influence of substrate surface morphologies on the nucleation and growth behaviors of cerium oxide films was investigated. The micropores had a strong influence on the random nucleation of the CeO₂ films. With increasing pore size on the surface of the NiW substrates, the epitaxial nucleation mode became the dominant mode. The amount of c-axis-oriented grains increased and the in-plane FWHM values decreased. On the other hand, the grooves had a weak effect on the crystallization of the CeO₂ films. Pure (00l)-oriented grains and sharp texture of the CeO₂ films could be acquired on the substrate with large grooves. This reveals that the substrate surface morphology plays a vital role in the crystallization behaviors of CeO₂ films.