Abstract
Nano-sized nickel substituted cobalt ferrite powders, <TEX>$Ni_xCo_{1-x}Fe_2O_4$</TEX> (<TEX>$0.0{\leq}x{\leq}1.0$</TEX>), were fabricated by the sol-gel method, and their crystallographic and magnetic properties were studied. All the ferrite powders showed a single spinel structure, and behaved ferrimagnetically. When the nickel substitution was increased, the lattice constants and the sizes of particles of the ferrite powders decreased. The M<TEX>$\ddot{o}$</TEX>ssbauer absorption spectra of <TEX>$Ni_xCo_{1-x}Fe_2O_4$</TEX> ferrite powders could be fitted with two six-line subspectra, which were assigned to a tetrahedral A-site and octahedral B-sites of a typical spinel crystal structure. The increase in values of the magnetic hyperfine fields indicated that the superexchange interaction was stronger, with the increased nickel concentration in <TEX>$Ni_xCo_{1-x}Fe_2O_4$</TEX>. This could be explained using the cation distribution, which can be written as, <TEX>$(Co_{0.28-0.28x}Fe_{0.72+0.28x})[Ni_xCo_{0.72-0.72x}Fe_{1.28-0.28x</TEX><TEX>}</TEX><TEX>]</TEX><TEX>O_4$</TEX>. The two values of the saturation magnetization and the coercivity decreased, as the rate of nickel substitution was increased. These decreases could be explained using the cation distribution, the magnetic moment, and the magneto crystalline anisotropy constant of the substituted ions.
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.
