Characterization of nanocrystalline TiO2–HfO2 thin films prepared by low pressure hot target reactive magnetron sputtering

Thin films of oxides were deposited by magnetron sputtering in reactive oxygen plasma from Ti–Hf mosaic target. The low pressure of reactive gas and appropriate power of plasma discharge during the deposition assumed pseudoepitaxial conditions of the layer growth. Thin films were characterized by means of X-Ray Diffraction (XRD), Atomic Force Microscopy (AFM), X-ray Photoelectron Spectroscopy (XPS) and optical transmission. On the basis of obtained results it was stated that the fabricated thin films were composed of the stoichiometric HfTiO4 single phase with average size of grains in the range of tenth of nanometers. Optical absorption spectra, derived in a conventional way from optical transmission measurements, yielded the optical band gap of about 3.42 eV. The grain size has changed after annealing in the range of 30 to 40 nm.