Effects of dipolar interactions on the zero-field-cooled magnetization of a nanoparticle assembly

Abstract

We investigate the effect of (weak) dipolar interactions on the field behavior of the temperature at the maximum of the zero-field-cooled magnetization of a polydisperse assembly of nanoparticles. For this purpose, we extend the Gittleman-Abeles-Bozowski model for the zero-field-cooled magnetization by computing the contribution of dipolar interactions to the longitudinal relaxation time. We show, in good qualitative agreement with many experimental observations, that the temperature at the maximum of the zero-field-cooled magnetization as a function of the applied field changes from a bell-like to a monotonically decreasing curve when the intensity of the dipolar interactions, or equivalently the sample concentration, increases.

9 aps pages (twocolumn), 3 figures

References in corpus (8)

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• Thermally activated escape rates of uniaxial spin systems with transverse field
• Relaxation time of weakly interacting superparamagnets
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• Thermodynamic perturbation theory for dipolar superparamagnets
• Magnetization of nanomagnet assemblies: Effects of anisotropy and dipolar interactions
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Cited by in corpus (7)

• Magnetic properties of Fe3O4 nanoparticles coated with oleic and dodecanoic acids
• Magnetic relaxation of a system of superparamagnetic particles weakly coupled by dipole-dipole interactions
• Interplay between surface anisotropy and dipolar interactions in an assembly of nanomagnets
• Effect of dipolar interactions and DC magnetic field on the specific absorption rate of an array of magnetic nanoparticles
• The magnetic structure factor of correlated moments in small-angle neutron scattering
• Increase in the magnitude of the energy barrier distribution in Ni nanoparticles due to dipolar interactions
• Magnetization Reversal in Two-dimensional Ensemble of Nanoparticles with Positional Defects