Effects of annealing temperature on the structure and static magnetic properties of NiZnCo ferrite thin films

The Ni_0.22Zn_0.52Co_0.03Fe_2.23O₄ ferrite thin films are deposited on Si (100) substrate by a radio-frequency magnetron sputtering method. The structure and magnetic properties of NiZnCo ferrite thin films with different annealing temperatures (600 °C, 700 °C, 800 °C and 900 °C) have been investigated. The secondary impurity phases of Fe₂O₃ and ZnO slowly disappeared with annealing temperature up to 800 °C. But, there are some FeSiO₃, Zn₂SiO₄ and SiO₂ impurity phases formation when the annealing temperature is 900 °C. The average grain size and surface roughness increased with annealing temperature up to 800 °C and then they decreased at 900 °C. The saturation magnetization gradually increases with annealing temperature up to 800 °C and then it decreases at 900 °C. Meanwhile, the coercivity monotonically decreases with annealing temperature up to 900 °C. - Highlights: • Effects of annealing on structural and magnetic properties of NiZnCo ferrite thin films are studied. • There are some impurity phases formation at 900 °C. • Maximum saturation magnetization is achieved at 800 °C. • Coercivity decreases with increasing annealing temperature