Synthesis of CoFe2O4 powder via PVA assisted sol–gel process

Abstract

CoFe2O4 ferrites were synthesized by sol–gel method, having metal nitrates as precursors and PVA as surfactant, followed by a heat treatment at 960 °C for 2 h. The ultrafine ferrite powders obtained have been characterized by X-ray diffraction, thermal gravimetry, differential scanning calorimetry and room temperature magnetic measurement studies. The morphology of the powder was identified by high resolution-scanning electron microscopy. X-ray diffraction results indicate that the resultant CoFe2O4 crystallites consist of spinel phase. Significant differences in magnetic properties of CoFe2O4 samples synthesized with various concentrations of PVA were observed. The magnetisation measurements show that when the PVA concentration increased, coercivity initially decreased and then increased where as retentivity and magnetisation decreased. The optimum concentration of PVA for the synthesis of CoFe2O4 ferrites is obtained from this investigation. Obviously this material can be used as an efficient candidate for practical recording purpose.