The microstructure and characteristics of magnetite thin films prepared by ultrasound-enhanced ferrite plating

Magnetite thin films were produced using the ultrasound-enhanced ferrite plating method. The effect of ferrite plating conditions on the microstructure and magnetic properties was investigated. The saturation magnetization (Ms) and the coercive force (Hc) of the magnetic thin films were 465-475 emu/cm³ and 60-65 Oe, respectively. Then, the applicability of the magnetite thin films as a CO gas sensor was investigated. The magnetite thin films were annealed in the air to be converted to maghemite ones through oxidation, which manifested CO gas sensitivity. Rair/Rgas=3.5 was obtained in the CO gas sensitivity at the operation temperature of 85°C, when the thin films were annealed at 300°C.