Synthesis and characterization of titania-coated MnZn ferrite nanoparticles

A novel core-shell structured composite, titania (TiO2) coated MnZn ferrite nanoparticle, was prepared by hydrolysis of titanium (IV) chloride (TiCl4) in the presence of MnZn ferrite nanoparticles synthesized with stearic acid gel method. The obtained samples were characterized by energy dispersive X-ray spectroscopy (SEM-EDS), X-ray diffraction (XRD) and transmission electron microscopy (TEM). Results show that spinel structural MnZn ferrite nanoparticles (6 nm average diameter) or their aggregates are coated by TiO2 nanoshell with anatase structure for annealed sample. The magnetic measurements were carried out on a vibrating sample magnetometer (VSM), and the measurement results indicate the reduction of the magnetization of the TiO2 coated MnZn ferrite nanoparticles compared with the uncoated ferrite nanoparticles. High coercivity also shows that the prepared uncoated and coated ferrite nanoparticles are not superparamagnetic.