Preparation and magnetic properties of CoFe_2O_4/TiO_2 composite films

Using (Ti(OC_4H_9)_4) and metal chlorates as starting materials, CoFe_2O_4/TiO_2 composite films were pre-pared by sol-gel method. The effects of heat treatment temperature and pH of the precursor on micro-structure and magnetic properties were studied. The phase structure of the samples was examined by X-ray diffraction. The microstructure was examined by scanning electron microscope, atomic force microscope and polarized microscope. The magnetic property was measured by vibrating sample magnetometer. The results show that the crystals of different phases grow up independently. CoFe_2O_4 is uniformly embedded into the TiO_2 matrix in the prepared composite films, and the growth of com-posite films is dependent on the heat treatment temperatures and PH of the precursor. The average size of CoFe_2O_4 crystal is 19 nm in Nanocomposite film prepared when the heat treatment temperature is 800℃ and the pH of the precursor is between 2 and 3. The magnetism of the composite films is en-hanced as the heat treatment temperature increases.