Improvement in Deposition Rate and Quality of Films Prepared by "Thin Liquid-Film" Ferrite Plating Method

We have plated polycrystalline CoxFe3-xO4 films by a "thin liquid film" method at T = 55 to 90°C and pH = 7.0, using NaNO2 as an oxidizing agent. The film quality was improved by (1) introducing a CH3COONH4 buffer to stabilize the pH, and (2) filtering the reaction solution. Thus we obtained a film deposition rate of 300 Å/min at 90°C for x = 0 and 0.43, without deterioration of the film quality. The deposition rate increased with the temperature. The Fe3O4 and CoxFe3-xO4 (x = 0.43) films plated at 90°C on glass substrates exhibited preferential orientation of the (100) and (111) planes parallel to the surface, respectively. Both films had a columnar structure normal to the surface plane, but the magnetization lay in the surface plane. Fe3O4 films plated at 90°C on ¿-Al2O3 (0001) and MgAl2O4 (100) crystal faces exhibited preferential orientation of the (111) and (100) planes, respectively, the oxygen-packing layer of the substrate coinciding with that of the ferrite film.