Work

Structural, dielectric and optical properties of CoFe2O4/Organoclay composites prepared by sol-gel autocombustion

Year: 2025

Type: article

Abstract: ODA-MNT, an organomodified montmorillonite (2, 4 and 6 wt%) supported CoFe2O4 nanocomposites were synthesized using sol-gel autocombustion method. The structural and microstructural characterizations of the samples were performed using XRD, Raman spectroscopy and SEM techniques. The dielectric and optical properties of the samples were also investigated. XRD analysis of naked CoFe2O4 revealed cubic spinel crystal structure. XRD patterns of CoFe2O4 samples supported with ODA-MNT (2, 4 and 6 wt%) closely resembled that of naked CoFe2O4 confirm the role of ODA-MNT as a supporting material. The value of crystallite size calculated by Williamson-Hall method were found to be 75, 82, 112 and 128 nm for 0, 2, 4 and 6 wt% of ODA-MNT supported compound respectively, indicating that ODA-MNT influences the crystallization process of CoFe2O₄. SEM analysis showed that particle size and degree of agglomeration are influenced by ODA-MNT content. Raman spectroscopic analysis confirms the synthesis of ODA-MNT supported CoFe2O4 composites with some sort of interaction between MNT sheets and CoFe2O4 nanoparticles allowing some cationic redistribution between octahedral and tetrahedral sites of Co ferrite structure. Dielectric constant of CoFe2O4/ODA-MNT composites were lower in all observed frequency range than pure CoFe2O4. The value of dielectric constant was found to be 19.7 for bare Co ferrite and 5.4 for ODA-MNT (2 wt%) supported CoFe2O4, which is 3.64 times lower than the value obtained in pure compound at 10 kHz. The value of band gap obtained for pure CoFe2O4 was 1.53 eV. The band gap was found to be lower for CoFe2O4/ODA-MNT (2, 4 wt%) compounds.

Source: Results in Materials

DOI: 10.1016/j.rinma.2025.100808