INVESTIGATION OF THE ANISOTROPY IN FROZEN NICKEL FERRITE IONIC MAGNETIC FLUID USING MAGNETIC-RESONANCE

Magnetic resonance is used to obtain the temperature dependence of the magnetic anisotropy of noninteracting NiFe2O4 nanoparticles from 100 to 250 K, The 10.3 nm particles are dispersed as a stable ionic magnet ic fluid which is frozen under the action of an external field to perf orm angular variation measurements. The thermal fluctuation of the eas y axis and magnetic moment about the direction of the external field i s included in order to obtain the anisotropy from the angular dependen ce of the resonance field, (C) 1998 Academic Press.