Abstract
The effects of calcium and zinc on the room-temperature coercivity of γ-Fe2O3 particles having cobalt ions adsorbed in 3M NaOH solution at 373K have been studied. When the Ca2+ ions are adsorbed on the γ-Fe2O3 prior to Co2+ ions adsorption, the coercivity of Co-modified γ-Fe2O3 significantly increases compared with that of γ-Fe2O3 modified only with Co2+ ions. In the case of Zn2+ ions, the coercivity of Co-modified γ-Fe2O3 is the same as that of γ-Fe2O3 modified only with Co2+ ions. The emission Mossbauer spectrum of57Co2+ adsorbed on the surfaces of γ-Fe2O3 after pretreating with Ca2+ ions consists of a typical sextet of Fe3+ ions with hyperfine magnetic field, whereas those of γ-Fe2O3 modified only with Co2+ ions and with both Zn2+ and Co2+ ions show nonmagnetic components in addition to magnetic one. The effects of Ca2+ and Zn2+ ions on the adsorption of cobalt on the surface of γ-Fe2O3 are discussed from the viewpoint of site preference energy of cations in ferrite and distribution ratio of each cation.
Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
