Cubic phase optimization and influence of post-annealing on microstructure, optical, wetting, and nanomechanical properties of zirconia thin films

Abstract

This work reports the fabrication of zirconia thin films by e-beam deposition, followed by thermal annealing in air at different temperatures to optimize the cubic phase without using any dopants or chemical stabiliser. The X-ray diffraction (XRD) and Raman spectra of zirconia films annealed at 500 °C reveal the formation of stable cubic phase with a crystallite size of 10.7 ± 0.8 nm at room temperature. Optical transparency of the zirconia film annealed at 500 °C is high, approaching 80% in the visible range. Increasing annealing temperature improves crystallinity, hydrophilicity and reduces nonradiative associated defects. The mechanical properties of zirconia films examined using static and dynamic nanoindentation demonstrate that hardness increases from 7.60 ± 0.26 GPa to 11.08 ± 0.90 GPa and elastic modulus increases from 170.74 ± 4.98 GPa to 210.13 ± 5.56 GPa when annealing temperature increases. The post-annealing temperature influences provide a method for tuning the optical, wetting and mechanical characteristics of zirconia thin film.