Structural and Optical Properties of Thermally Oxidized Zirconium Dioxide Films

Zirconium oxide (ZrO2) thin films were grown by thermal oxidation of metallic zirconium films deposited by sputtering of zirconium target by DC magnetron sputtering technique. The metallic zirconium films were thermally oxidized in oxygen atmosphere at different temperatures in the range from 300°C to 500°C. The as-deposited and oxidized films were characterized for their chemical composition by energy dispersive X-ray analysis, structure by X-ray diffraction, chemical binding configuration with Fourier transform infrared spectroscopy and optical absorption using UV-Vis NIR spectrophotometer. Metallic zirconium film was polycrystalline in nature with hexagonal structured Zr. The zirconium films were transformed into monoclinic ZrO2 with polycrystalline in nature at oxidation temperature of 400°C. Crystallite size of the ZrO2 films increased from 78 nm to 108 nm with increase in the oxidation temperature form 400°C to 500°C. The optical band gap increased from 5.42 eV to 5.46 eV and refractive index decreased from 2.05 to 2.02 with increase of oxidation temperature from 400°C to 500°C.