Effect of 100 kGy γ-irradiation on the structural, electrical and magnetic properties of CoFe2O4 NPs

Magnetic nanoparticles of CoFe2O4 NPs were fabricated using simple sol-gel auo-combustion synthesis and irradiated with total gamma dose of 50 kGy and 100 kGy maintaining a dose rate of 0.7 kGy/h. More emphasis was given for calculating an error free value of Lattice constant (alpha) by re-evaluating Debay-Sherrer value with Nelson-Riley extrapolation function (N-R). Bradley-jay function (B-J) and specimen mis-alignment error was elaborated while discussing the unit cell parameters. SEM images described the irradiation effects on polycrystalline and aggregated morphology of CoFe2O4 NPs. The prominent absorption bands (v(1), v(2), v(3), v(4)) in room temperature FTIR spectra confirmed the formation of ferrite phase and stretching vibrations in gamma-irradiated CoFe2O4 NPs. Decreasing DC-resistivity, increasing drift mobility and the measured range of activation energy (0.120-0.281 eV) was discussed as a function of gamma-irradiation indicating ferrimagnetic behaviour of CoFe2O4 NPs. Several magnetic parameters (Mr, Hc, H-K, n(B)(e)) were determined from the M-H loop recorded at room temperature. Magnetic anisotropy constant (K-1) of gamma irradiated CoFe2O4 NPs was deduced using 'Law of approach' (LA) fit to saturation. (C) 2016 Elsevier B.V. All rights reserved.