Effect of Sm3+–Gd3+ on structural, electrical and magnetic properties of Mn–Zn ferrites synthesized via combustion route

Abstract

Nanocrystalline Mn0.4 Zn0.6 SmxGdyFe2-(x+y)O4 (x = y = 0.01, 0.02, 0.03, 0.04 and 0.05) were synthesized by combustion route. The detailed structural studies were carried out through X-ray diffractometer (XRD), Fourier transform infrared spectroscopy (FTIR), transmission electron microscopy (TEM). The results confirms the formation of mixed spine phase with cubic structure due to the distortion created with co-dopants substitution at Fe site in Mn–Zn ferrite lattice. Further, the crystallite size increases with an increase of Sm3+–Gd3+ ions concentration while lattice parameter and lattice strain decreases. Furthermore, the effect of Sm–Gd co-doping in Mn–Zn ferrite on the room temperature electrical (dielectric studies) studies were carried out in the wide frequency range 1 GHz–5 GHz. The magnetic studies were carried out using vibrating sample magnetometer (VSM) under applied magnetic field of 1.5T and also room temperature electron paramagnetic resonance (EPR) spectra's were recorded. From the results of dielectric studies, it shows that the real and imaginary part of permittivities are increasing with variation of Gd3+ and Sm3+ concentration. The magnetic studies reveal the decrease of remnant, saturation magnetization and coercivity with increasing of Sm3+–Gd3+ ion concentration. The g-value, peak-to-peak line width and spin concentration evaluated from EPR spectra correlated with cations occupancy. The electromagnetic properties clearly indicate that these materials are the good candidates which are useful at L and C band frequency.