Comparative study of CaFe2O4 with nanocomposites CaFe2O4@SiO2 and the effect of silica shell thickness on their physical and magnetic properties

In this paper, a comparison between CaFe2O4 (CFO) nanoparticles and CaFe2O4@SiO2 nanocomposites (CFO@Si) with different amounts of (TEOS) and the effect of silica shell thickness on the physical and magnetic properties of these materials has been made. Nanoparticles (CFO) were first synthesized using the self-combustion sol-gel method, and then their surface was coated using silica and the Stöber sol-gel method. The resulting nanoparticles and nanocomposites were characterized using XRD, FESEM, TEM, AFM, FTIR, BET, BJH, and VSM analyses. The results showed that increasing the TEOS concentration resulted in a thicker silica shell, which increased the dispersion, improved the stability, and prevented the aggregation of the nanocomposite (CFO@Si) compared to the nanoparticles (CFO). It was also found that the magnetic properties of the nanocomposite (CFO@Si) decreased with increasing thickness of the silica shell compared to the nanoparticles (CFO). Consequently, this paper highlights the critical role of TEOS concentration and silica shell thickness in improving the physical and magnetic properties of the nanocomposite (CFO@Si) compared to the nanoparticles (CFO). These findings can help improve the applications of magnetic nanocomposites in various scientific and industrial fields.