The influence of Mn doping on structural , thermal , particle size and conduction properties of nano Ni Zn ferrites

Document Type : Regular Articles

Author

Physics Department Faculty of science Tanta University

Abstract

The current work involves the use of flash auto combustion procedure to synthesize nano-ferrites Ni0.3Zn0.7−x MnxFe2O4, (x = 0.00, 0.15, 0.25, 0.35, 0.45, and 0.55) annealing at 800°C for 4h. X-ray diffraction, XRD, pattern analysis verified the structure phase. The Rietveld observed peaks correspond to two phases; spinel ferrites, belong to the Fd-3m space group, and hematite belongs to the R-3c space group. The thermogram (TGA) of the as prepared samples in the temperature range from 50 to 1000°C and shows two distinct regions. The small weight loss value was noticed in our sample in both regions is due to the structural stability for the as prepared sample which confirm by x-ray data analysis. The grain size decreased by increasing Mn content from 0.74 to 0.33 μm. The M" curve increases with applied frequency showing relaxation peak and ends with sharp decrease at high frequency. The cole-cole diagram illustrates the presence of semi-circles depending on the presence of the relaxation effect at low frequency. The diameter of semi-circles decreases by the increasing of the Mn content from 5.3 to 1.25 cm. At low frequency region the conductivity is constant and almost equal zero representing σˊ is frequency independent (DC conductivity) up to103 Hz then it starts to increase gradually with the increase of frequency showing some dispersion. Also, the conductivity increases with the increase of Mn content. The value of Z′ at different Mn2+ concentrations overlap at particularly high frequencies which refers to the probable liberation of space charges.

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