Magnetic properties of Cr-substituted Co-ferrite nanoparticles synthesized by citrate-gel autocombustion method

M Raghasudha,P Veerasomaiah,D Ravinder

doi:10.1186/2193-8865-3-63

Abstract

Abstract A series of Co-Cr nanoferrites having the chemical formula CoCr x Fe2 − x O4 (x = 0.0, 0.1, 0.3, 0.5, 0.7, 0.9, and 1.0) were synthesized by citrate-gel autocombustion method at a very low temperature (180°C). The X-ray diffraction analysis of as-synthesized powders and sintered powders has confirmed the formation of single-phase cubic spinel structure. The average particle size of the synthesized ferrites was 6 to 12 nm. Magnetic susceptibility measurements using Faraday magnetic susceptibility balance showed the paramagnetic nature of the ferrites. Magnetic properties of Co-Cr nanoferrites were measured using a vibrating sample magnetometer at room temperature in the applied field of 15 kOe. The saturation magnetization decreased from 33.84 to 13.83 emu/g with increase in Cr3+ concentrations, indicating the fact that the lesser magnetic Cr3+ ions substitute Fe3+ ions in the octahedral sublattice of the ferrite. With improvement in the magnetic properties, the synthesized nanoferrites become soft magnetic materials. Such materials are useful in transformer and motor cores to minimize the energy dissipation with the alternating fields associated with AC electrical applications. The coercivity of pure CoFe2O4 was larger than that of the Cr-doped cobalt ferrites.

Highlights

Nanoparticles are very important and have a distinct property, that is, they exhibit larger surface-area-to-volume ratio
From the X-ray diffraction (XRD) patterns of the as-synthesized powders, it is clear that the as-burnt powder is in single phase with a spinel structure which indicates that the ferrite can be directly formed after the autocombustion of the gel without heat treatment
A series of CoCrxFe2 − xO4 (x = 0.0, 0.1, 0.3, 0.5, 0.7, 0.9, and 1.0) nanoparticles have been successfully synthesized by citrate-gel autocombustion technique at a low sintering temperature

Summary

Introduction

Nanoparticles are very important and have a distinct property, that is, they exhibit larger surface-area-to-volume ratio. Transition metal oxide nanoparticles represent a broad class of materials that have been investigated extensively due to their interesting catalytic, electronic, and magnetic properties relative to those of the bulk counterparts, and the wide scope of their potential applications [2]. Among these materials, ferrites have attracted immense attention of the scientific community because of their novel properties and technological applications especially when the size of the particles approaches to nanometer scale [3]. This is because of its advantages such as good stoichiometric control and the production of ultrafine particles with a narrow size distribution in a relatively short processing time at a very low temperature

Methods

Results

Conclusion