engleski

Superparamegnetic relaxation in Cu_xFe_3-xO_4 (x=0.5 and x=1) nanoparticles

The scope of this article is to report very detailed results of the measurements of magnetic relaxation phenomena in the new Cu0.5Fe2.5O4 nanoparticles and known CuFe2O4 nanoparticles. The size of synthesized particles is (6.5&plusmn ; ; 1.5) nm. Both samples show the superparamagnetic behaviour, with the well-defined phenomena of the blocking of magnetic moment. This includes the splitting of zero-field-cooled and field-cooled magnetic moment curves, dynamical hysteresis, slow quasi-logarithmic relaxation of magnetic moment below blocking temperature. The scaling of the magnetic moment relaxation data at different temperatures confirms the applicability of the simple thermal relaxation model. The two copper-ferrites with similar structures show significantly different magnetic anisotropy density and other magnetic properties. Investigated systems exhibit the consistency of all obtained results.

Single-domain nanoparticles; Superparamagnetism; Magnetic relaxation; Magnetic viscosity;

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