Thin films of CoFe2O4 spinel ferrite were prepared on silicon (100) substrates at low temperature by means of a modified polyvinyl alcohol processing, and the structure and magnetic properties as a function of the only one varied calcination temperature were investigated in detail and optimized. The CoFe2O4 ferrite films had a single phase spinel structure and were well-crystallized at temperature above 600 °C, which is much lower than the required temperature in the traditional ceramic method (about 1000 °C). The films annealed at and above 500 °C for 1h showed the grain sizes between 9 and 40 nm, and exhibited high coercivities and high saturation magnetization. Co-ferrite films prepared by sol-gel method and annealed at 700 °C had excellent potential for important technological applications, such as information storage and magnetooptical devices.
Origin of high-coercivity in nanocomposites by single-precursor sol-gel method
