Ordered arrays of magnetic nanowires investigated by polarized small-angle neutron scattering

TL;DR

This study uses polarized small-angle neutron scattering to analyze the magnetic structure and stray fields in ordered arrays of ferromagnetic Co nanowires embedded in alumina, revealing detailed magnetization distributions during hysteresis.

Contribution

It demonstrates that PSANS can effectively determine real-space magnetization and stray field distributions in nanostructured magnetic systems, advancing magnetic characterization techniques.

Findings

PSANS reveals field-dependent magnetization distributions.

Magnetostatic simulations agree with experimental data.

Technique distinguishes magnetic form factor and stray fields.

Abstract

Polarized small-angle neutron scattering (PSANS) experimental results obtained on arrays of ferromagnetic Co nanowires ($\phi\approx13$ nm) embedded in self-organized alumina (Al$_{2}$O$_{3}$) porous matrices are reported. The triangular array of aligned nanowires is investigated as a function of the external magnetic field with a view to determine experimentally the real space magnetization $\vec{M}(\vec{r})$ distribution inside the material during the magnetic hysteresis cycle. The observation of field-dependentSANSintensities allows us to characterize the influence of magnetostatic fields. The PSANS experimental data are compared to magnetostatic simulations. These results evidence that PSANS is a technique able to address real-space magnetization distributions in nanostructured magnetic systems. We show that beyond structural information (shape of the objects, two-dimensional organization) already accessible with nonpolarized SANS, using polarized neutrons as the incident beam provides information on the magnetic form factor and stray fields \textgreek{m}0Hd distribution in between nanowires.