Growth of nanocrystalline TiO2 thin films and crystal anisotropy of anatase phase deposited by direct current reactive magnetron sputtering

This work describes the growth and elastic anisotropy of nanocrystalline TiO2 films deposited by direct current reactive magnetron sputtering. The films are nanocrystalline in the gas pressure range 0.4–1.0 Pa even in the absence of substrate bias and substrate heating. It has been observed that gas pressure has a considerable effect on the phase evolution of TiO2 and at a higher pressure, nanocrystalline anatase can be produced with a greater crystallinity and dense surface. X-ray diffraction line profile analysis of anatase TiO2 has been performed and the integral breadth expressions of line broadening due to the domain size and lattice microstrain are combined on the basis of the Williamson–Hall (WH) method. The Miller indices dependence of Youngʹs modulus is estimated on the basis of the Reuss approximation for polycrystalline aggregates. Youngʹs modulus shows strong anisotropy. The anisotropic nature of the elastic medium has been introduced in the classical WH plot under the uniform stress deformation model (USDM) and uniform deformation energy density model (UDEDM). USDM represents the better fit of the experimental data.