Thermal behavior and effect of SiO2 and PVA-SiO2 matrix on formation of Ni–Zn ferrite nanoparticles

Abstract

The paper presents the synthesis of ZnFe2O4/SiO2, NiFe2O4/SiO2, Ni0.4Zn0.6Fe2O4/SiO2 and Ni0.4Zn0.6Fe2O4/PVA-SiO2 nanocomposites by a modified sol–gel method. The influence of matrix type on the formation of Ni-, Zn- and Fe-succinate precursors and their decomposition into ferrites within the pores of SiO2 or PVA-SiO2 matrices was investigated by thermal analysis. The decomposition processes, formation of crystalline phases and mass changes during samples annealing at different temperatures were also assessed by thermal analysis. The formation and decomposition of succinates and the formation of the matrix were studied by Fourier transform infrared spectroscopy, while the formation of main (ZnFe2O4, NiFe2O4) and secondary phases (SiO2) was studied by X-ray diffraction analysis. The influence of matrix type on the formation of the crystalline phases was also investigated. Transmission electron microscopy revealed spherical-shaped ferrite particles with particle size of 4–50 nm. The particle size increases with increasing Zn content and annealing temperature. The coloring properties and the potential ceramic applications of the obtained dark-brown–black powders were tested by their incorporation in opaque tile glazes and application on ceramic tile.