Characterization and magnetic properties of nanocrystalline Mg1-xCdxFe2O4 (x = 0.0–0.8) ferrites synthesized by glycine-nitrate autocombustion method

Abstract

Sol-gel autocombustion method using glycine as fuel and complexing agent was utilized to synthesize nanocrystalline Mg1-xCdxFe2O4 (x = 0–0.8) ferrites. An increase in adiabatic flame temperature with x during the combustion reaction was demonstrated, based on the thermodynamic calculations. The X-ray diffraction (XRD) and Fourier transform infrared spectroscopy (FTIR) results confirmed that a single-phase spinel structure in all samples is formed at a remarkably lower temperature and with a larger production rate compared to the standard ceramic and other wet-chemical methods. Crystallites growth from 98 nm to 320 nm, enhanced X-ray density and a linear increase in both theoretical and experimental lattice constants, with comparable values were observed with introduction of cadmium. Analysis of the XRD patterns, using the Bertaut method along with a detailed Rietveld analysis reflected a different cations distribution and evolution of some structural parameters with cadmium, compared to the earlier studies. The Field-emission scanning electron microscopy (FESEM) results showed that the average particle size of the synthesized ferrites increases from 161 to 520 nm for x = 0 to x = 0.8, respectively. The magnetic measurements revealed that the saturation magnetization (Ms) initially increases and reaches the maximum value of 46 A m2 kg−1 at x = 0.2, and subsequently decreases, while the coercivity (Hc) and remanent magnetization (Mr) continuously decline with x values. The present magnetic results for x = 0.0 − 0.4, show a noticeable improvement in magnetic softness compared to previous researches on the Mg-Cd ferrites obtained by other chemical methods.