Effect of Al Doping on Magnetic Properties of Co-Mn Nanoferrites Synthesized via Citrate-Gel Method

Abstract

The structural and magnetic properties of aluminium substituted Co-Mn nanoferrites synthesized via a chemical route viz. citrate-gel autocombustion method have been reported. Aluminium content has been varied from x=0 to x=1 with an increment of 0.2 in Co0.75Mn0.25AlxFe2-xO4. The structural confirmation was done with the basic characterization techniques such as XRD study, FTIR spectroscopic and the surface morphology was examined using SEM and EDX spectroscopic analysis. To study the optical absorption behaviour of the prepared ferrites, UV-visible spectral analysis was carried out. XRD analysis established the formation of cubic spinel structure of the materials with the average crystallite size of 15.5 nm to 19.94 nm. FTIR spectra has shown two absorption peaks that are characteristic of spinel nano ferrites. From the UV-visible spectral data, energy band gap (Eg) values were evaluated. The data witnessed an increase in the Eg value of the ferrite by doping of Al3+ ion into the ferrite. Room temperature magnetization measurements were carried out before and after aluminium doping in the samples using vibrating sample magnetometer. It was revealed that the substitution of aluminium in the lattice has modified the material into a soft magnetic material. Consequently, they find applications in transformer and motor cores.