Microstructure and magnetic properties ofNiZn ferrite thin films prepared by sol-gel method
(State Key Laboratory of Electronic Thin Films and Integrated Devices, University of Electronic Science and Technology of China, Chengdu 610054, China)
Abstract: Ti4+ substitution for Fe3+ in Ni0.5Zn0.5Fe2O4 (NZF) ferrite thin films were realized by sol-gel method and annealing at 600℃ for 30 min in the air. Crystal structure and lattice constant determination was performed by X-ray diffractometer (XRD). Surface microstructure was observed by scanning electron microscope (SEM) and atomic force microscope (AFM), and the magnetic properties were measured by vibrating sample magnetometer (VSM). XRD analyses of the samples show that Ni0.5+xZn0.5TixFe2−2xO4 (NZTF) films with x varying from 0 to 0.15 in steps of 0.05 are composed of single phase with spinel structure. And the lattice parameter, particle size and the diffraction intensity of the films increase with substitution of Ti as the result of the larger radius ions entering the lattice. SEM and AFM show homogeneous grain size of each sample, but there is a few differences in grain size with different Ti-substitution contents. As the nonmagnetic Ti4+ substitutes Fe3+, both the saturation magnetization and coercivity decrease.
Key words: Ti-substitution; NiZn ferrite thin films; sol-gel method; microstructure; magnetic properties