Effective magnetic moment of magnetic multicore nanoparticles
Artikel i vetenskaplig tidskrift, 2009

We carry out Monte Carlo simulations to study the effective magnetic moment mu(eff) in the low-field region of magnetic multicore nanoparticles. Transmission electron microscopy and scanning electron microscopy images show that these particles contain a number of magnetic nanocrystals (MNCs) randomly packed in a single cluster of total volume V(tot). We illustrate how the initial magnetic susceptibility chi(0) of magnetic multicore nanoparticles can be straightforward derived from mu(eff) computed at zero magnetic field. We observe that dipolar interactions between MNCs and polydispersity of the MNCs contribute to increase and to decrease mu(eff)/V(tot), respectively, while magnetic anisotropy of the MNCs does not show any effect. In all three cases, mu(eff)/V(tot) can be described by a linear relation to (mu B/k(B)T)(2) that we analytically derived for low applied fields.

exchange interactions (electron)

nanoparticles

Monte Carlo methods

transmission electron microscopy

scanning electron microscopy

magnetic anisotropy

magnetic moments

magnetic susceptibility

Författare

Vincent Schaller

Chalmers, Teknisk fysik, Elektronikmaterial och system

Göran Wahnström

Chalmers, Teknisk fysik, Material- och ytteori

Anke Sanz-Velasco

Chalmers, Teknisk fysik, Elektronikmaterial och system

Stefan Gustafsson

Chalmers, Teknisk fysik, Mikroskopi och mikroanalys

SuMo Biomaterials

Eva Olsson

Chalmers, Teknisk fysik, Mikroskopi och mikroanalys

Peter Enoksson

Chalmers, Teknisk fysik, Elektronikmaterial och system

Christer Johansson

Physical Review B - Condensed Matter and Materials Physics

1098-0121 (ISSN)

Vol. 80 9 092406-

Ämneskategorier

Annan fysik

Den kondenserade materiens fysik

Styrkeområden

Materialvetenskap

DOI

10.1103/PhysRevB.80.092406