SOARES, J.M. ; CONCEIÇÃO, O.L.A. ; MACHADO, F.L.A. ; PRAKASH, A. ; RADHA, S. ; NIGAM, A.K. . Magnetic couplings in CoFe2O4/FeCo-FeO core-shell nanoparticles. Journal of Magnetism and Magnetic Materials, v. 374, p. 192-196, 2014.

Publicado em 11.03.2019 às 23:28:23

CoFe2O4/FeCo–FeO core–shell nanoparticles with an average particle size of about 4.3 nm were prepared by reducing nanoparticles of superparamagnetic cobalt-ferrite under hydrogen and oxygen atmospheres. The low temperature magnetic hysteresis showed an interesting behavior which has only been observed in thin film multilayer systems. At low magnetic fields View the MathML source the behavior is dominated by the magnetic structure of the magnetically soft shell while for higher values of H the exchange-spring core–shell coupling plays a major role. A particle model which is coherent with the observed magnetic behavior has been also proposed