Sol-gel synthesis, magnetic and magneto-optical properties of CoFe 2- xTb xO 4 nanocrystalline films

The nanocrystalline thin films of terbium-doped cobalt ferrite were fabricated by a sol-gel method, and the effects of crystallization conditions on the phase, morphology, magnetic and magneto-optical (MO) properties of products were investigated. Due to its large radius, the doping content, x, of Tb ³⁺ ion inside cobalt spinel cannot exceed 0.2. The CoFe _{2- x}Tb _xO ₄ films consist of the grains with the average size smaller than 50 nm even annealed up to 800°C. Saturation magnetization, coercive force and MO rotation are strongly dependent on the annealing temperature.