Induced size effects of Gd 3+ ions doping on structural and magnetic properties of Ni-Zn ferrite nanoparticles

Gd 3+ ions substituted in Ni0.5Zn0.5GdxFe2-xO4 (where x = 0.1, 0.2, 0.3) ferrite nanoparticles in the size range from 15 to 25 nm were prepared by chemical method. The effect of Gd 3+ ions in spinel structure in correlation to structural and magnetic properties have been studied in detail using XRD, HRTEM and EPR techniques. The spin resonance confirms the ferromagnetic behaviour of these nanoparticles and higher order of dipolar-dipolar interaction. On increasing Gd 3+ ions concentrations, the super exchange interaction i.e. increase in movement of electron among Gd 3+ - O - Fe 3+ in the core group and the spin biasing in the glass layer has been interpreted. The decrease in ‘g’ value and increase in relaxation time is well correlated with the change of particle size on different concentrations of Gd 3+ ions in Ni-Zn ferrite. Copyright © 2012 VBRI Press.