Structural, Electrical, and Magnetic Properties of Zn Substituted Magnesium Ferrite

Zinc substituted magnesium (Mg–Zn) ferrites with the general formula Mg1−xZnxFe2O4 (x=0.00, 0.25, 0.50, 0.75, and 1.00) were prepared using the solution combustion route. The dried powder after calcination (700 °C for 2 h) was compacted and sintered at 1050 °C for 3 h. The structural, morphological, dielectric and magnetic properties of the sintered ferrites were studied using X-ray diffraction (XRD), scanning electron microscopy (SEM), impedance spectroscopy, and vibration sample magnetometry (VSM). The XRD analysis of sintered samples confirmed that the expected spinel cubic phase was formed for all samples. The crystallite sizes evaluated using Scherre's formula were found to be in the range of 47–80 nm. SEM analysis showed homogeneous grains with a polyhedral structure. The electrical conductivity increased with increasing frequency, which is normal dielectric behavior for such materials. The dielectric constant, dielectric loss tangent, and AC conductivity were found to be lowest for x=0.50. The VSM results showed that the zinc concentration had a significant influence on the saturation magnetization and coercivity

Thermal effect on magnetic properties of Mg-Zn ferrite nanoparticles

Magnesium-zinc ferrite (Mg0.5Zn0.5Fe 2O4) powder was prepared by a solution combustion method using a mixture of sugar and urea as fuel. To understand the effect of size and crystallinity on its magnetic properties, combustion derived ferrite powder was subjected to calcination at different temperatures in an ambient atmosphere. The powder X-ray diffraction data of calcined samples was used to determine the effect of calcination on phase formation and crystallite size. The average crystallite size of single phase cubic spinel ferrite nanoparticles was found to increase with an increase in calcination temperature. Transmission electron microscopy images showed a uniform particle size distribution with average particle sizes varying in the range of 30-124 nm. Magnetic properties were found to be affected by particle size; we observed a linear relationship between the saturation magnetization and particle size. Low values of squareness ratio and coercivity implied the superparamagnetic nature of the samples. © 2013 Elsevier B.V

Structural and magnetic studies of Mg(1-x)ZnxFe 2O4 nanoparticles prepared by a solution combustion method

Nanocrystalline Mg(1-x)ZnxFe2O4 (x = 0.0, 0.25, 0.5, 0.75 and 1) ferrites were prepared by a solution combustion method using a mixture of fuels. The structural and magnetic properties of the as-prepared samples were studied using powder X-ray diffraction (PXRD), Fourier transform infrared (FTIR) spectroscopy, scanning electron microscopy (SEM), transmission electron microscopy (TEM), UV-Vis absorption spectra and vibrating sample magnetometer (VSM) measurements. The PXRD analysis of all the samples revealed the single phase cubic structure with the space group Fd3Ìm. The average crystallite size determined from the PXRD data was found to increase from 12 nm to 25 nm with an increase in the Zn content from x = 0 to x = 1. The IR absorption spectra exhibited two prominent peaks, which are assigned to tetrahedral and octahedral vibrations. The saturation magnetization, magnetic moment and remenant magnetization increases with an increase in the zinc content up to x = 0.5 and decrease thereafter. The observed behavior is consistent with Yaffet-Kittel magnetic ordering. The ZFC (zero field cooled) and FC (field cooled) measurements of magnetization revealed that the blocking temperature is well below room temperature. © 2013 Elsevier B.V. All rights reserved