Deposition of TiO2 thin films on steel using a microwave activated chemical bath

Microwave activated chemical bath deposition (MW-CBD) is a simple and novel technique in which the substrate is heated directly by microwaves and very well adhered layers are obtained. It has not been used previously for TiO2 deposition on metals. We show that it is possible to coat stainless steel with TiO2 using MW-CBD. Two different precursor solutions are used for TiO2 deposition on steel grade 316. TiO2 thin films on steel substrates were characterized using SEM and Raman spectroscopy. Raman analysis showed that amorphous TiO2 is obtained using the precursor solution based on TiOSO4; however, films show anatase crystal structure when using the precursor solution based on (NH4)2TiF6. Thermal treatment of the films improved crystallinity and also allowed iron diffusion from the steel substrate into the film. Crystalline phases that appeared due to heat treatment were identified from Raman spectra. MW-CBD allows simple low temperature coating of a metal substrate with TiO2 and this should be useful for a number of different applications.