Microwave irradiation as an alternative source for conventional annealing: a study of pure TiO2, NiTiO3, CdTiO3thin films by a sol–gel process for electronic applications

The lower temperature and shorter timescale for microwave irradiation may be ascribed to the activating and facilitating effect of microwaves on solid-phase diffusion. Using the microwave-heating process, it is possible to achieve enhanced mechanical properties such as greater hardness, improved scratch resistance, and structure texturing. In the present investigation, thin films of pure TiO 2 and their respective perovskite-structured thin films, namely NiTiO 3 and CdTiO 3 , have been prepared by simple and cost-effective sol–gel processing on Si(100) substrates and subjected to irradiation with different microwave powers for 10 min. X-ray diffraction (XRD), scanning electron microscopy (SEM) and x-ray photoelectron spectroscopy (XPS) techniques have been employed to characterize the structural, morphological and elemental composition of the films. It is evident that there is a dramatic change in the structural and morphological properties of the films irradiated in microwaves compared to conventional annealing at high temperature. A plausible mechanism for the formation of the anatase phase of TiO 2 and perovskite structures with a rhombohedral phase formation at low microwave powers has also been discussed. This new innovative microwave heating could open a door for advanced technologies to cut process costs in the post-treatment of materials.