Preliminary studies of thin metal oxide films prepared by deposition of an aerosol generated ultrasonically from aqueous nitrate solutions

Thin Co, Co-Fe and Co-Fe-Cr metal oxide films were prepared by deposition of an aerosol generated by ultrasonic excitations from aqueous nitrate solutions. Commercial gray glass has been used as substrates. Thermogravimetric (TG and DTG) measurements of initial nitrate components as well as their homogenized mixtures were performed and optical properties, i.e. reflectance and transmittance of the deposited films in the UV-visible and near-infrared regions up to 4761 nm, were measured. The surface roughness of the films was also measured and their chemical durability tested. The reflectance values obtained for 550 nm radiation wavelength were 25-33% for Co-oxide films compared to 20-30% for films deposited by us from a pneumatic aerosol, or values of 10-15% reported by others. The reflectance was 21-28% for Co:Fe = 15:1 films and up to 26% and 30% for Co:Fe:Cr = 15:1:0.25 and Co:Fe:Cr = 12:3:1 films, respectively. The reflectance of the uncoated reference glass was 5%. The surface roughness values of films deposited from ultrasonic aerosol dropped to about 50-60% of the value measured for films deposited from pneumatic aerosol. At the same time the chemical durability of films deposited from ultrasonic aerosol has approximately doubled.