A comparison between structural and magnetic behavior of cobalt ferrite synthesized via solid state and chemical methods

Abstract

Cobalt ferrite oxide (CoFe _2 O _4 ) was synthesized by two different methods of mechanochemical and combustion. The phase composition and the chemical bonding information of the two powders were investigated by x-ray diffraction (XRD) method and Fourier Transform Infrared Spectroscopy (FT-IR). Field emission scanning electron microscopy (FESEM) was used to study the microstructure and morphology and elemental analysis was performed with EDS. The magnetic properties were analyzed at room temperature using a vibrating sample magnetometer (VSM). According to the structural and elemental analyses, cobalt ferrite was directly synthesized in the combustion method. However, the mechanochemical route was not successful in phase formation, even after heating at high temperatures. The hysteresis loops of VSM analysis showed that the CoFe _2 O _4 powder from combustion method resulted in higher saturation magnetization and coercive field than the powder synthesized by mechanical milling. The inferior magnetic behavior of the powder from solid state method is attributed to the presence of Co ^3+ in the starting powder, which results in a non-spinel complex between cobalt and iron ions.

Keywords

• ferromagnetic
• cobalt ferrite
• spinel
• mechanical alloying
• combustion
• magnetic property