Study of Magnetic Property of Sn Doped Ni-Zn-Fe Nanoparticles
The Ni0.6+xZn0.4SnxFe2-2xO4 (x=0.00 to 0.04) samples were prepared by solution route technique. These samples were characterized by XRD and EPR spectra at X-band frequency (~9.2 GHz). The XRD spectra of these ferrites confirm the formation of spinel structure. The average particle size calculated by using Scherrer’s formula was found to be of the order of 24.7 nm. The EPR spectra of these ferrites are mainly due to Fe3+ ions. Fe2+ ions have very short spin-lattice relaxation time and therefore EPR spectra of Fe2+ could be observed only at very low temperature. This fact is also supported by the isomer shift values of these ferrites obtained from Mössbauer spectroscopy. The variation of geff and ΔHPP with Sn4+ concentration is attributed to the variation of superexchange interaction. Moreover in this system the dominant process of relaxation is the spin lattice relaxation rather than the spin-spin interaction.