Fe-oxide Nanoparticles: a natural playground for testing the ISP model

Magnetic dipolar interaction plays a major role in systems of ferrimagnetic Fe-oxide nanoparticles. Dipolar interaction plays a role over a wide range of temperatures above blocking temperature and results in the onset of the Interacting Superparamagnetic (ISP) regime. In this paper, distinctive aspects and basic issues of the ISP model are discussed by exploiting the experimental data obtained in well-characterized magnetite nanoparticles

Annealing effects on permeability relaxation in amorphous ferromagnets

The relaxation of the magnetic permeability has been measured as a function of temperature in amorphous ribbon samples annealed at different temperatures and for different annealing times. The results are analyzed to get informations on the very nature of the activated processes giving rise to permeability relaxation effects