Magnetic neutron scattering on nanocomposites: decrypting cross-section images using micromagnetic simulations

TL;DR

This paper introduces a micromagnetic simulation method to analyze magnetic neutron scattering in nanocomposites, enabling detailed study of magnetic microstructure and field-dependent scattering contributions, complementing experimental data.

Contribution

The novel approach allows for the field-dependent decomposition of magnetic scattering contributions using micromagnetic simulations, enhancing understanding of nanomagnet microstructure.

Findings

Explains dipolar correlations in two-phase nanocomposites.

Shows explicit dependence of magnetization Fourier coefficients on scattering vector.

Provides a tool to interpret neutron scattering experiments.

Abstract

We have used numerical micromagnetics for the calculation of the magnetic (small-angle) neutron scattering cross section of nanocomposites. The novel aspect of our approach consists in the possibility to study the applied-field dependence of the individual contributions to the total magnetic scattering. Such a micromagnetic tool ideally complements neutron experiments in which one generally measures only a weighted sum of the Fourier components of the magnetization. The procedure furnishes unique and fundamental information regarding the magnetic microstructure and corresponding magnetic scattering from nanomagnets. In particular, our simulation results explain the recent observation of dipolar correlations in two-phase nanocomposites and provide an answer to the question of the explicit dependence of the magnetization Fourier coefficients on the scattering vector.