Determination of nanocrystal size distribution in magnetic multicore particles including dipole-dipole interactions and magnetic anisotropy: A Monte Carlo study
Paper i proceeding, 2010

A correct estimate of the size distribution (i.e., median diameter D and geometric standard deviation σ) of the magnetic nanocrystals (MNCs) embedded in magnetic multicore particles is a necessity in most applications relying on the magnetic response of these particles. In this paper we use a Monte Carlo method to simulate the equilibrium magnetization of two types of multicore particles: (I) MNCs fused in a random compact cluster, and (II) MNCs distributed on the surface of a large carrier sphere. The simulated magnetization data are then fitted using a common method based on a Langevin equation weighted with a size distribution function. Finally, the fitting parameters Dm and σm are compared to the real parameters Dp and σp used to generate the MNCs. Our results show that fitting magnetization data with a Langevin model that neglects magnetic anisotropy and dipole-dipole interactions leads to an erroneous estimate of the size distribution of the MNCs in multicore particles. The magnitude of the error depends on the particle morphology, number of MNCs contained in the particle and magnetic properties of the MNCs.

Size distribution

Magnetic anisotropy

Magnetization

Metropolis algorithm

Magnetic multicore nanoparticles

Monte Carlo simulation

Dipole-dipole interactions

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

Peter Enoksson

Chalmers, Teknisk fysik, Elektronikmaterial och system

Christer Johansson

Imego AB - The Institute of Micro and Nanotechnology

AIP Conference Proceedings

0094-243X (ISSN) 1551-7616 (eISSN)

Vol. 1311 42-50

Ämneskategorier

Annan teknik

Styrkeområden

Produktion

DOI

10.1063/1.3530051

ISBN

978-073540866-1

Mer information

Skapat

2017-10-08