Synthesis and Characterization of Co_0.6Zn_0.4Mn_0.3Fe_1.7O₄ Magnetic Nanoparticles

Abstract

In the recent time spinel ferrite magnetic nanoparticles have been largely studied owing to various applications of these materials in the information storage, ferro-fluid technology, magnetocaloric effect, refrigeration and medical diagnostics. In this category cobalt ferrite (CoFe₂O₄) nanoparticles specifically gained huge research attention and prepared by various chemical methods. However, further investigations are still needed on the substituted CoFe₂O₄(CFO) nanoparticles to explore their various characteristics. In this paper we present our results on Mn and Zn substituted cobalt ferrite (Co_0.6Zn_0.4Mn_0.3Fe_1.7O₄) nanoparticles prepared by chemical co precipitation method. The x ray diffraction pattern of as prepared Co_0.6Zn_0.4Mn_0.3Fe_1.7O₄ (CZFMO) nanoparticles indicated their average particle size =20 nm. Magnetic properties of these nanoparticles before and after thermal annealing have been compared. Magnetization (M) vs. field (H) loop measurements at T = 293 K on as prepared and thermally annealed CZFMO nano powders revealed an unusual feature contrary to CFO nanoparticles prepared under same conditions. The saturation magnetization (Ms) decreases after the thermal annealing unlike the usual increase in Ms observed for CFO nanoparticles. These nano sized CZFMO powder samples are further characterized by low temperature magnetic measurements; Raman spectroscopy and Fourier transform infrared spectroscopy.