Structural, morphological and magnetic properties of FeCo-(Fe,Co)3O4 nanocomposite synthesized by proteic sol-gel method using a rotary oven

Abstract

FeCo nanoparticles coated with (Fe,Co)3O4 (magnetite doped with cobalt) were synthesized by the proteic sol-gel chemical route. The synthesized materials were characterized by Thermogravimetry (TG), X-Ray Diffraction (XRD), Scanning Electron Microscopy (SEM), Transmission Electron Microscopy (TEM), vibrating-sample magnetometer (VSM) and Mössbauer spectroscopy (MS). The results show that the increase in temperature and the choice of the correct air/N2 flow directly influence on the final physical-chemical properties of the nanocomposite. The SEM and TEM images confirmed that a thin layer of oxide was formed on the alloy, indicating that it was obtained a self-assembled FeCo-(Fe,Co)3O4 nanocomposites. In addition, the VSM results show that a possible exchange-spring coupling in magnetic FeCo-(Fe,Co)3O4 nanoparticles occurred with high saturation magnetization from FeCo alloy and high coercivity from (Fe,Co)3O4. The rotary oven allows the uniform contact of the powder with the atmosphere of synthesis during the different oxidation-reduction steps, generating more homogeneous particles.