Effect of Low Temperature Annealing on Microstructural and Optical Properties of (BaTiO₃)_0.84(CeO₂)_0.16Thin Films

Abstract

(BaTiO3)0.84(CeO2)0.16 thin lms were prepared by electron beam evaporation method. X-ray diraction and scanning electron microscopy revealed the amorphous structure for the as-prepared lms. The thin lms were annealed at temperatures: 200, 300, 400 and 500• C for 1 h in air. Small and low intensity crystalline peaks were observed at annealing temperature of 200• C for 1 h. The intensity and the number of the crystalline peaks were increased with increasing annealing temperature. Nanocrystals, of dimensions in the range 6076 nm, were obtained when the annealing was performed at 500• C. The indexed diraction pattern of the annealed thin lm revealed a monoclinic structure. A two-layer model was used to describe the experimental ellipsometric data. The Bruggeman eective medium approximation was used to describe the surface roughness layer and the Cauchy dispersion relation was used to describe the main (BaTiO3)0.84(CeO2)0.16 layer. The optical constants of the thin lms over 3001100 nm spectral range were measured. The optical band gap showed gradual decrease with the annealing temperature. The accurate determination of the optical constants of the thin lms is very useful and should be taken into consideration in the design of devices using optical thin lms technology.

Correlation of film thickness to optical band gap of Sol-gel derived Ba0.9Gd0.1TiO3 thin films for optoelectronic applications

“…Barium titanate (BaTiO3) is a ferroelectric material that has gained much attention in recent decades for its excellent electrical and optical properties, and the simplicity of its crystal structure that can adapt variety types of dopant [1][2]. The incorporation of different element as dopant into BaTiO3 has been extensively investigated in order to improve its original properties and extends the areas of application of barium titanate [3][4].…”