Structural and Magnetic Investigations of Silica coated 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 sample has been further heat treated at 250°C, 500°C,750°C and 1000°C. Their structure and morphology related properties were desirably investigated by XRD, FTIR, TEM characterization techniques. Further, with the help of vibrating sample magnetometer (VSM) the magnetic properties have been successfully analysed. Furthermore, the structure and magnetism related properties of these nanocomposites are also understood with heating effects. With increasing calcinations temperature, crystallite size of CoFe2O4:SiO2 nanocomposites was also found to increase. The room temperature magnetic measurements have shown a strong relation of saturation magnetization, retentivity and coercivity with annealing temperature.

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

“…A clear trend of microstructural change is found with temperature. Our magnetic findings of these silica coated cobalt-ferrite nanocomposites indicate [19] that retentivity, saturation magnetization, and coercivity can vary with crystallite size and is strongly depended on temperature. Hence, our results indicate the individual appearance of silica embedded nanoparticles has been enhanced in the case of higher temperatures and they may be suitably designed for maximum heating efficiency in magnetic hyperthermia for cancer treatment [6][7][8].…”

“…Calculated values of crystallite size using the Debye-Scherrer equation (D D-S ) and Williamson-Hall method (D W-H ), strain and lattice parameter with increasing temperature are listed in Table 1. In our earlier communication, we have reported the magnetic properties of these samples and retentivity, saturation magnetization and coercivity revealed a strong dependence on the crystallite size and showed promise as a material for magnetic hyperthermia [19].…”

“…The silica embedded cobalt ferrites may be proposed as the suitable materials for delivery of targeted nanomedicine in most harmful environments. Magnetic investigations of silica coated cobalt-ferrite nanocomposites have earlier been reported [19] and the retentivity, saturation magnetization, and coercivity revealed a strong dependence on their crystallite size. Our results suggest the potential applications of these silica embedded magnetic nanoparticles in the biomedical field, especially for hyperthermia treatment [6][7][8]19].…”

“…Magnetic investigations of silica coated cobalt-ferrite nanocomposites have earlier been reported [19] and the retentivity, saturation magnetization, and coercivity revealed a strong dependence on their crystallite size. Our results suggest the potential applications of these silica embedded magnetic nanoparticles in the biomedical field, especially for hyperthermia treatment [6][7][8]19]. This paper reports novel data on the properties, synthesis and structure using XRD, FTIR, SEM, and thermal stability by TGA-DTG of silica embedded cobalt ferrite (CoFe 2 O 4 :SiO 2 ) nanocomposites prepared by co-precipitation method and heat treated at 250, 500, and 750 C for 24 h.…”

Silica supported spinel structured cobalt ferrite multifunctional nanocatalyst for hydration of nitriles and oxidative decarboxylation of phenylacetic acids

“…Hence, it is important to develop a recoverable and recyclable catalytic system that is capable of accomplishing decarboxylation at sp 3 ‐carbon center under base and ligand free condition. Earlier, we have reported the synthesis of aldehydes by oxidative decarboxylation of phenyl acetic acids by using transition metal catalyst [ 59 ] ; however, that protocol required high temperature (120°C), 10–12 h reaction time, and DMSO solvent. So, we have been searching for a new methodology, which could promote the reaction in comparatively greener reaction conditions.…”