Abstract:
Nanocrystalline monophasic cobalt substituted zinc ferrite with general formula Co sub(x) Zn sub((1-x)) Fe sub(2) O sub(4) (x = 0.0, 0.5, 1.0) were synthesized by precursor combustion method. The precursors namely, hexa-hydrazine cobalt zinc ferrous succinate with formulae Co sub(x) Zn sub((1-x)) Fe sub(2)(C sub(4) H sub(4) O sub(4)) sub(3.) 6N sub(2) H sub(4) (x = 0.0, 0.5, 1.0) were characterized by IR, CHNS, ICP-AES analysis, and their thermal studies were carried out by TG-DTA, TG-DTG, and isothermal mass loss studies. The 'as prepared' Co-Zn ferrites obtained by auto-catalytic thermal decomposition of precursors, on initial ignition, were characterized by XRD, IR, EDAX, TEM, and SEM. The SAED and XRD studies confirmed the formation of crystalline single phase nano Co-Zn ferrites. The morphology of these 'as prepared' ferrites was studies by TEM analysis which confirmed the particles to be in the nanometer range (20-30 nm). The increase in cobalt concentration resulted in reduced lattice parameter. The electrical resistivity declined while the Curie temperature surged with a decreased zinc concentration in 'as prepared' Co-Zn ferrites. The magnetization studies with the applied field at 300 K and 50 K displayed a gradual increase in magnetization values with the rise in cobalt content while confirming the super-paramagnetic nature of Co-Zn ferrite nano-system.
