Structural, spectroscopic and magnetic study of nanocrystalline Ni-Zn ferrites

A series of Ni-Zn ferrites is prepared in the form of nanoparticles using a novel combustion method. The novelty lies in the direct mixing of reactants, which yields more effective and pure final product of nano ferrites. The XRD (X-Ray Diffraction) patterns are analyzed for determining the structural parameters and for predicting the cation distribution in the ferrites. The XRD data show the formation of single-phase spinel structure having grain sizes around 10-20 nm. Morphological analysis using SEM (Scanning Electron Microscope) show agglomerated flakes of particles having large pores on the surface. FTIR (Fourier Transform Infra-red Spectroscopy) spectra of the samples confirm the formation of spinel structure and further lend support to the proposed cation distribution. Magnetic study using VSM (Vibrating Sample Magnetometer) shows that there is a magnetic phase refinement towards the single domain nature with the addition of nickel. The samples exhibit low magnetization values ranging from 4 to 27 emu/g which is suggestive of triangular lattice arrangement of moments in these ferrites. Electron Paramagnetic Resonance (EPR) spectra reveal that spread of peak-to-peak line width with concentration supports the magnetic study using VSM and hold our prediction of the presence of Y-K angles. (C) 2009 Elsevier B.V. All rights reserved.