Characterization of Cobalt Ferrite Nano-particles Synthesized by Polymerized Complex Sol-gel Method

In this study, single-phase cobalt ferrite nanoparticles with nearly spherical morphology and an average size of approximately ۳۰-۵۰ nm were synthesized via a straightforward sol-gel method. This method relied on a polycondensation reaction between citric acid, benzoic acid, and ethylene glycol, carried out without adjusting the pH and under strongly acidic conditions, eliminating the need for gel aging. These characteristics render the method flexible and practical for synthesizing various types of nanocomposite materials. The thermal behavior, phase evolution, and magnetic properties of the products were assessed using DTA, XRD, and VSM techniques. Additionally, SEM and TEM were utilized to examine particle size and morphology. Thermal studies indicated a three-step process: loss of residual water in the gel, de-esterification, and decarboxylation of COOH groups, culminating in the formation of cobalt ferrite. The impact of calcination temperature on the phases and magnetic properties of the powders was thoroughly analyzed. Heat treatment in air at ۷۵۰°C for ۱ hour successfully produced pure spinel cobalt ferrite nanoparticles. In contrast, annealing at ۸۵۰°C for the same duration resulted in the highest magnetization among all samples tested. This investigation established a clear relationship between the microstructure of the nanoparticles and their magnetic properties, highlighting the importance of annealing temperature in the magnetic behavior of cobalt ferrite nanoparticles.

کلیدواژه ها:

Cobalt ferrite ، Nanopowder ، Polymerized complex ، Magnetic properties