AC susceptibility of an assembly of nanomagnets: combined effects of surface anisotropy and dipolar interactions

F. Vernay 1 Z. Sabsabi 1 H. Kachkachi 1
1 PROMES - Procédés, Matériaux et Energie Solaire
Abstract : We compute the AC susceptibility of a weakly dipolar-interacting monodisperse assembly of magnetic nanoclusters with oriented anisotropy. For this purpose we first compute the relaxation rate in a longitudinal magnetic field of a single nanomagnet taking account of both dipolar interactions in the case of dilute assemblies and surface anisotropy. We then study the behavior of the real and imaginary components of the AC susceptibility as functions of temperature, frequency, surface anisotropy and inter-particle interactions. We find that the surface anisotropy induces an upward shift of the temperature at the maximum of the AC susceptibility components and that its effects may be tuned so as to screen out the effects of interactions. The phenomenological Vogel-Fulcher law for the effect of dipolar interaction on the relaxation rate is revisited within our formalism and a semi-analytical expression is given for the effective temperature is given in terms of inter alia the applied field, surface anisotropy and dipolar interaction.
Type de document :
Article dans une revue
Physical Review B : Condensed matter and materials physics, American Physical Society, 2014, 90 (9), 〈10.1103/PhysRevB.90.094416〉
Liste complète des métadonnées

Littérature citée [35 références]  Voir  Masquer  Télécharger
https://hal-univ-perp.archives-ouvertes.fr/hal-01223239
Contributeur : Olivier Savoyat <>
Soumis le : lundi 2 novembre 2015 - 12:23:48
Dernière modification le : jeudi 11 janvier 2018 - 06:22:15
Document(s) archivé(s) le : mercredi 3 février 2016 - 10:49:53

Fichier

1407.2503v2.pdf
Fichiers produits par l'(les) auteur(s)

Identifiants

Collections

UNIV-PERP | PROMES

Citation

F. Vernay, Z. Sabsabi, H. Kachkachi. AC susceptibility of an assembly of nanomagnets: combined effects of surface anisotropy and dipolar interactions. Physical Review B : Condensed matter and materials physics, American Physical Society, 2014, 90 (9), 〈10.1103/PhysRevB.90.094416〉. 〈hal-01223239〉

Exporter

BibTeX TEI DC DCterms EndNote

Partager

Métriques

Consultations de la notice

53

Téléchargements de fichiers

46

Contact

support.ccsd.cnrs.fr
hal.support@ccsd.cnrs.fr
Logo CCSD