Effect of experiment parameters on the structure and magnetic properties of NiZn-ferrite films

NiZn-ferrite thin films were deposited by radio frequency magnetron sputtering. The effects of sputtering pressure, substrate temperature, and annealing temperature on the structure and magnetic properties of the NiZn-ferrite thin films were investigated. The results revealed that the lower sputtering pressure was beneficial for the crystallization and grain growth of the NiZn-ferrite films, and the saturation magnetization and coercivity of the films monotonously decreased with increasing the sputtering pressure. Moreover, it was also suggested that a higher substrate temperature could improve the crystallinity and saturation magnetization of the thin films. Additionally, the saturation magnetization monotonously increased with increasing the annealing temperature, while the coercivity exhibited a minimum at an annealing temperature of about 600 °C. The change of saturation magnetization and coercivity as a function of sputtering pressure, substrate temperature and annealing temperature could be attributed to the varied crystallinity, grain size, cation distribution and the intrinsic stress of the films.