Preparation of Ni 0.65Zn 0.35Cu 0.1Fe 1.9O 4/SiO 2 nanocomposites by sol–gel method

Abstract

Ni 0.65Zn 0.35Cu 0.1Fe 1.9O 4/SiO 2 nanocomposites were fabricated by the sol–gel method using tetraethylorthosilicate as a precursor of silica, and metal nitrates as precursors of NiZnCu ferrite. With infrared spectra, X-ray diffraction, transmission electron microscope, Raman spectra, Mössbauer spectroscopy and vibrating sample magnetometer measurements, the formation of single phase nanocrystalline NiZnCu ferrites dispersed in silica matrix is confirmed when the sample is annealed at 550°C. The transition from the paramagnetic to the ferromagnetic state is observed as the annealing temperature increases from 750°C to 1150°C. The magnetic properties of these nanocomposites are clearly size dependent. The saturation magnetization increases with the annealing temperature.