Authors: A.R. Phani and S. Santucci
Affilation: University of L'Aquila, Italy
Pages: 343 - 346
Keywords: sol-gel process, thin films, microwave irradiation, hardness, annealing, scratch resistance
Thin films of Al2O3 have been prepared by simple sol-gel process on to quartz substrates, and the as deposited films are subjected to annealing different temperatures and microwave irradiation at different powers. It is evident that there is a dramatic change in the mechanical properties of the films irradiated in microwave compared to conventional annealing process. There is a two-fold increase in the hardness (8.2 GPa) of the Al2O3 films when exposed to microwave compared to conventional annealing (4 GPa). Similar changes are also observed when the films are deposited on polyacrylic substrates. The change in the structural, mechanical, optical, and tribological properties and plausible mechanism are discussed. The lower temperature and shorter time with microwave irradiation might be ascribed to the activating and facilitating effect of microwave on solid phase diffusion. This will have a strong impact on coatings applied in nanotechnology, microtechnology and biotechnology industries. This could be a great advantage for the hard, protective, corrosion, abrasion, wear resistance, thermal barriers, optical, optoelectronic, microelectronic, polymer thin films that are applied on plastic, quartz, glass, metal substrates, where conventional annealing process is a limiting factor.