Effect of heat treatment on the microstructural properties of silica embedded cobalt ferrite nanocomposites

Abstract

Silica coated cobalt ferrite (CoFe2O4:SiO2) nanocomposites were synthesized by co-precipitation technique using metal nitrates as precursors. The as-prepared samples were heat treated at different temperatures of 250, 500 and 750 °C for 24 h. Structural, thermal, and morphological behavior of nanocomposites are investigated by XRD, FTIR, TGA-DTG, and SEM characterization results, useful in biomedical applications. With increasing calcinations temperature from 250 to 500 °C and 750 °C an increase in crystallite size of CoFe2O4:SiO2 nanocomposites has been determined from 20.26 to 28.95 nm and 38.76 nm by Williamson–Hall method, respectively. Furthermore, by increasing the temperature from 250 to 750 °C the lattice parameter and strain values have been found to increase from 8.0321 to 8.0691 Å and 1.01 × 10−2 to 3.75 × 10−3, respectively. Analysis of TGA results found no weight loss when the sample was heated beyond 700 °C and thus complete decomposition of precursors has led to the formation of stable nanocomposite structures at high temperatures. SEM analysis of synthesized samples at 750 °C revealed well developed nanoparticles of CoFe2O4: SiO2 with inter-granular porosity.

Keywords

• silica
• cobalt ferrite
• coating
• nanocomposites
• co-precipitation