Temperature dependent structural, morphological, FTIR, optical, magnetic properties of NiMgZn ferrites

Abstract

NiMgZn ferrites with chemical composition Ni 0.2 Mg 0.3 Zn 0.5 Fe 2 O 4 nanomaterials were synthesized using the sol-gel technique. The various properties of the samples prepared at three different calcination temperatures (T) of 400, 450 and 500 • C/5 hr were studied. The X-ray diffraction study confirmed the single-phase cubic spinel structure (JCPDS 08-0234) for 400 & 500 • C calcined samples and with Fe 2 O 3 as an impurity phase for 450 • C calcined sample with lattice parameter values 8.296 to 8.376Å. The surface morphology and EDX spectra observed with field emission scanning electron microscope (FESEM) images confirmed the nano-sized irregular shaped grain development at low calcination temperatures. The force constants are determined using FTIR spectroscopy confirmed the M-O bonds present in ferrites. Optical band gap properties studied and found that NiMgZn ferrites have band gaps in semiconducting region from 1.68 to 1.75 eV. The susceptibility-temperature (χ-T) dependence is studied using a Bartington MS2B Dual Frequency instrument in heating and cooling modes and magnetic transition temperature (T c) were determined. The highest magnetic susceptibility of 1293 is observed for 500 • C calcined material. By using VSM, the M-H loop, magnetic properties are studied, which showed that this material is ferrimagnetic. Also, the magnetic moments and saturation magnetizations (M s) are calculated. The maximum saturation magnetization 97.20 emu/g is observed for 400 • C calcined sample.