Superparamagnetic relaxation in CuxFe3−xO4 (x=0.5 and x=1) nanoparticles

Abstract

The scope of this article is to report very detailed results of the measurements of magnetic relaxation phenomena in the new Cu 0:5 Fe 2:5 O 4 nanoparticles and known CuFe 2 O 4 nanoparticles. The size of synthesized particles is (6:571:5) 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. r

Tetragonal copper ferrite obtained by self-propagating combustion

“…For this reason, the traditional methods (ceramic method, etc.) are replaced by the wet chemistry methods: hydro/solvothermal synthesis, microemulsion, sol-gel and complexation tehnique [3][4][5][6][7][8][9]. A new and very promising method is the self-propagating combustion [10][11][12][13][14][15].…”

Relaxation phenomena in super spin glass nanoparticle manganite La0.7Ca0.3MnO3

“…1with respect to T ln(t/s 0 ) scaling variable. The values m 0 S (denoted with circles) are obtained directly from the experimental data, as a negative slope of curve M vs. T ln(t/s 0 ) at each temperature T m[23].…”

Size distribution of FeNiB nanoparticles

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