Modification in Magnetic Properties of CoFe2O4 Ferrite Nanoparticles Induced by 100MeV O+7 Ion Irradiation

Abstract

Abstract In this work CoFe2O4 ferrite nanoparticles were prepared via sol-gel method using citric acid as chelating agent. The prepared nanoparticles was sintered at 700°C and the crystallite size is found 34 nm. In this investigation the effect of irradiation of 100 MeV O+7 beam on these nanoparticles with two fluences 5×1012 and 5×1013 ions/cm2 are studied. After irradiation the crystallite size is found to be reduced which is confirmed by transmission electron micrograph. The retentivity and coercivity changes with a measurable value while the saturation magnetization reduces slightly. The value of remanent magnetization increased from 30 emu/g to 34.6 emu/g, it can be attributed to increase of magnetic hardness. The increase in squareness ratio after irradiation leads to increase in anisotropic energy barrier of CoFe2O4 ferrite nanoparticles. Anisotropy field about doubles after irradiation and corresponding anisotropy constant also doubles with the used fluences.