Optical characteristics of transparent samarium oxide thin films deposited by the radio-frequency sputtering technique

Transparent metal oxide thin films of samarium oxide (Sm2O3) were prepared on pre-cleaned fused optically flat quartz substrates by radio-frequency (RF) sputtering technique. The as-deposited thin films were annealed at different temperatures (873, 973 and 1073 K) for 4 h in air under normal atmospheric pressure. The topological morphology of the film surface was characterized by using atomic force microscopy (AFM). The optical properties of the as-prepared and annealed thin films were studied using their reflectance and transmittance spectra at nearly normal incident light. The estimated direct optical band gap energy (E-g(d)) values were found to increase by increasing the annealing temperatures. The dispersion curves of the refractive index of Sm2O3 thin films were found to obey the single oscillator model.