title: Radiolytic formation of Fe3O4 nanoparticles: influence of radiation dose on structure and magnetic properties.
abstract: Colloidal Fe3O4 nanoparticles were synthesized using a gamma-radiolysis method in an aqueous solution containing iron chloride in presence of polyvinyl alcohol and isopropanol as colloidal stabilizer and hydroxyl radical scavenger, respectively. Gamma irradiation was carried out in a 60Co gamma source chamber at different absorbed doses. Increasing the radiation dose above a certain critical dose (100 kGy) leads to particle agglomeration enhancement, and this can influence the structure and crystallinity, and consequently the magnetic properties of the resultant particles. The optimal condition for formation of Fe3O4 nanoparticles with a uniform and narrow size distribution occurred at a dose of 100 kGy, as confirmed by X-ray diffractometry and transmission electron microscopy. A vibrating sample magnetometry study showed that, when radiation dose increased, the saturation and remanence magnetization decreased, whereas the coercivity and the remanence ratio increased. This magnetic behavior results from variations in crystallinity, surface effects, and particle size effects, which are all dependent on the radiation dose. In addition, Fourier transform infrared spectroscopy was performed to investigate the nature of the bonds formed between the polymer chains and the metal surface at different radiation doses.
authors.affiliation: School of Applied Physics, Faculty of Science and Technology, Universiti Kebangsaan Malaysia, Bangi, Selangor, Malaysia.
authors.forename: Alam
authors.initials: A
authors.lastname: Abedini
authors.affiliation: School of Applied Physics, Faculty of Science and Technology, Universiti Kebangsaan Malaysia, Bangi, Selangor, Malaysia.
authors.forename: Abdul Razak
authors.initials: AR
authors.lastname: Daud
authors.affiliation: School of Applied Physics, Faculty of Science and Technology, Universiti Kebangsaan Malaysia, Bangi, Selangor, Malaysia.
authors.forename: Muhammad Azmi
authors.initials: MA
authors.lastname: Abdul Hamid
authors.affiliation: School of Applied Physics, Faculty of Science and Technology, Universiti Kebangsaan Malaysia, Bangi, Selangor, Malaysia.
authors.forename: Norinsan
authors.initials: N
authors.lastname: Kamil Othman
mesh_terms: D005290:Ferric Compounds / Q000737:chemistry* / Q000528:radiation effects; D005720:Gamma Rays; D058185:Magnetite Nanoparticles / Q000737:chemistry* / Q000528:radiation effects / Q000648:ultrastructure; D010316:Particle Size
chemical_list: D005290:Ferric Compounds; D058185:Magnetite Nanoparticles