Fabrication and characterization of spinel-type CO1-XZNXFE2-XNIXO4 Mesoporousmicrospheres
Spinel-type CoFe2O4 mesoporous microspheres were synthesized through a facile hydrothermal method and post calcination approach. Structural properties of the material are characterized by means of X-ray powder diffraction (XRD), Raman spectroscopy, Fourier transform infrared spectroscopy, field emission scanning electron microscopy (FESEM) and transmission electron microscopy (TEM) with selected area electron diffraction (SAED). XRD and SEAD patterns reveal the phase pure spinel-type cubic crystal formation. FESEM and high resolution-TEM investigations reveal that the mesoporous microspheres are constructed by self-assembled aggregates of nanoparticles which are interconnected in such a way to form the highly stable porous microspheres. AC impedance spectroscopy is used to study the electrical properties of the sample at different temperatures. In order to understand the charge-carrier transport mechanism of the sample, electrical equivalent circuits are performed. The conductivity of the sample increases with temperature and reveals the conventional extrinsic semiconductor behaviour.