The comparative study on microstructure and magnetic properties of cobalt ferrite/MWCNTs nanocomposite prepared using mechanical mixing and hydrothermal routs

The mechanical mixing (MM) and hydrothermal are known as prevalent and facile synthesis methods of the nanocomposite. In this research, the cobalt ferrite/ multi-wall carbon nanotubes (CF/MWCNTs) nanocomposites synthesized by these methods and microstructure and magnetic properties were investigated. The nano-composites were characterized using X-ray diffraction (XRD), Field emission electron microscope (FESEM), Raman spectroscopy, thermal gravimetric analysis (TGA), differential thermal analysis (DTA), and vibration sample magnetometer (VSM). Furthermore, the specific surface area of prepared nanocomposite was measured by the Brunauer-Emmett-Teller (BET) method. The single-phase cobalt ferrite without any impurities was observed in XRD patterns. The samples' mean crystallite size was calculated by the Williamson -Hall and Rietveld methods which show that samples prepared by hydrothermal procedure has a larger crystallite size. Also, the obtained nanocomposites by both methods have a suitable phase distribution of CF nanoparticles and MWCNTs according to the FE-SEM micrographs. Moreover, the maximum magnetization (Mmax) for samples prepared by MM and hydrothermal methods were 35.6 and 49.5 emu/g, respectively. It is noteworthy that the Mmax values increase by 13.5 emu/g for sample synthesized by hydrothermal method compare to MM prepa-ration. The results revealed that the presence of MWCNTs in the synthesis medium leads to cobalt ferrite nanoparticle growth and thus improves the magnetic properties.