TEMPERATURE DEPENDENT STRUCTURAL AND ELECTRICAL ANALYSIS OF Mn-Zn NANO FERRITES

Abstract

Mn-Zn ferrite powders (Mn0.5Zn0.5Fe2O4) were prepared by the chemical co-precipitation method. The effect of annealing temperature on the crystalline phase formation and dielectric properties were investigated by X-ray diffraction and impedance analyzer respectively. The DTA/TGA analysis was carried out to know decomposition mechanism. Ferrites decomposed to Fe3O4 above 873 K annealing temperature. Particle size increased with increasing annealing temperature between 7-13 nm. The resistivity decreased with increase in temperature showing semiconductor like behaviour. The measured dc resistivity for samples at 573 K was found to be 2.86×105 Ω- cm and 4.02×105 Ω- cm. The dc conductivity data are explained using Mott’s variable range hopping (VRH) model and different related parameters were calculated. Dielectric constant decreased with increasing frequency and temperature. Relaxation peak occurred for loss tangent versus frequency curves. The ac conductivity explained using small polaron tunnelling (SPT) model.