Sol-Gel Synthesis and Magnetic Properties of CoFe2-xRExO4(RE=Tb, Dy) Nanocrystalline Films

The nanocrystalline thin films of CoFe2-xRExO4(RE=Tb, Dy) were fabricated by sol-gel processing. By varying the doping content of rare earth ions, x, and the annealing conditions, the difficult crystallization of spinel phase was found for the samples with x>0. 3, which is ascribed to te large radii of rare earth ions. AFM observation indicated that the grain size can be controlled between 20 [similar to] 50 nm and the sol-gel derived thin films have a surface with a low roughness of 4 [similar to] 5 nm. The doping of Tb3+ and Dy3+ ions inside spinel can enhance the coercive force of CoFe2O4 films.EI045062