How cobalt ions substitution changes the structure and dielectric properties of magnesium ferrite?

Nanomaterials of cobalt substituted magnesium ferrite with the general formula Mg1-xCoxFe2O4 (x=0.00, 0.17, 0.34, 0.50, 0.67, 0.84, 1.00) were prepared for the first time by sol gel auto-combustion method using glycine as the chelating/combustion agent. Solid phase chemical reactions were monitored by using infrared spectroscopy (FT-IR), indicating finally the absence of organic phases and nitrate groups. The X-ray diffraction analysis confirmed the spinel mono-phase formation in the Fd3m space group for all samples. The crystallite size estimated by FullProf 2000 program was found in the range of 42-78 nm. Formation of nanosize particles was confirmed through scanning electron microscopy. The results obtained in the dielectric study showed normal dielectric behavior for all materials. The dielectric constant and dielectric loss decrease with increase in frequency and reaches a constant value at high frequencies. Nanomaterials of magnesium ferrite substituted with cobalt showed a very low dielectric loss ranging between 0.01 and 0.02 at frequencies over 10 MHz. (C) 2014 Elsevier Ltd and Techna Group S.r.l. All rights reserved.