Core-shell structure; strain; superparamagnetism; ESR; dipolar interactions. Core-shell structure; strain; superparamagnetism; ESR; dipolar interactions.
1National Physical Laboratory, Dr. K.S. Krishnan Marg, New Delhi 110012, India
2Netaji Subhas Institute of Technology, University of Delhi, Sector-3, Dwarka, New Delhi 110078, India
Adv. Mater. Lett., 2012, Current Issue, 3 (5), pp 415-420
Publication Date (Web): Sep 16, 2012
Copyright © IAAM-VBRI Press
Nanocrystalline NixCo1-xFe2O4 were synthesized and studied for their structural and magnetic properties. The effect of doping ion concentration on lattice parameter, crystallite size and the lattice strain pertaining to the ionic radii has been investigated. Electron microscopy supports the parameters and gives morphological view of the system. The magnetic measurement reveals the information on the effect of stoichiometry variation in existing superparamagnetism. Further, the spin dynamics and their role on dipolar interactions, extent of superexchange and spin-spin relaxation among nanoparticles have been investigated. Also, an attempt has been made to understand the UV irradiation effect on photosensitive Co2+ ion on Ni ferrite by in-situ electron spin resonance measurements.
Core-shell structure, strain, superparamagnetism, ESR, dipolar interactions.