Rapid Preparation of Ferrite Films by Plasma-Enhanced MOCVD

Oxide thin films of composition Ni_yZn_xFe_3-x-yO₄ (0≤x+y≤1.0) were prepared at high deposition rates of between 200 and 300 nm/min by plasma-enhanced MOCVD from a gas mixture containing Fe(C₅H₇O₂)₃, Zn (C₅H₇O₂)₂, Ni(C₅H₇O₂)₂, and O₂, at an rf power of 400 W or higher and a temperature of 600°C under a high flow-rate for the source vapors (e.g. 2.35×10^-5 mol/min for the Fe source). The X-ray diffraction patterns of the films indicated that Zn_xFe_3-xO₄ (0≤x≤0.8), Ni_yFe_3-yO₄ (0≤y≤1.0) and Ni_0.4Zn_0.4Fe_2.2O₄ films consisted of only a spinel phase with good crystallinity. However, a small NiO (111) peak was observed together with the spinel peaks in the diffraction pattern of the Ni_0.8Zn_0.2Fe_2.0O₄ film. SEM images of the films showed that they had densely columnar structures, irrespective of their compositions.