2024-03-28T20:49:51Zhttps://gredos.usal.es/oai/requestoai:gredos.usal.es:10366/1382362022-02-07T15:42:38Zcom_10366_138184com_10366_4512com_10366_3823col_10366_138185
Vivas, Laura G.
Yanes Díaz, Rocío
Michels, Andreas
2018-09-07T08:18:11Z
2018-09-07T08:18:11Z
2017-10-12
Scientific Reports 7, 13060 (2017)
2045-2322
http://hdl.handle.net/10366/138236
National Research Fund of Luxembourg (AFR 8865354)
Junta de Castilla y Leon (SA090U16)
[EN] Magnetic small-angle neutron scattering (SANS) is a powerful technique for investigating magnetic nanoparticle assemblies in nonmagnetic matrices. For such microstructures, the standard theory of magnetic SANS assumes uniformly magnetized nanoparticles (macrospin model). However, there exist many experimental and theoretical studies which suggest that this assumption is violated: deviations from ellipsoidal particle shape, crystalline defects, or the interplay between various magnetic interactions (exchange, magnetic anisotropy, magnetostatics, external field) may lead to nonuniform spin structures. Therefore, a theoretical framework of magnetic SANS of nanoparticles needs to be developed. Here, we report numerical micromagnetic simulations of the static spin structure and related unpolarized magnetic SANS of a single cobalt nanorod. While in the saturated state the magnetic SANS cross section is (as expected) determined by the particle form factor, significant deviations appear for nonsaturated states; specifically, at remanence, domain-wall and vortex states emerge which result in a magnetic SANS signal that is composed of all three magnetization Fourier components, giving rise to a complex angular anisotropy on a two-dimensional detector. The strength of the micromagnetic simulation methodology is the possibility to decompose the cross section into the individual Fourier components, which allows one to draw important conclusions regarding the fundamentals of magnetic SANS.
National Research Fund of Luxembourg (AFR)
8865354
Junta de Castilla y Leon
SA090U16
application/pdf
eng
Nature Publishing Group
Attribution 4.0 International
http://creativecommons.org/licenses/by/4.0/
info:eu-repo/semantics/openAccess
Magnetism
Small-angle neutron scattering
Magnetic nanoparticles
Material physics with surface physics
Micromagnetic simulations
Small-angle neutron scattering modeling of spin disorder in nanoparticles
info:eu-repo/semantics/article
SA090U16
AFR 8865354