NuMagSANS: a GPU-accelerated open-source software package for the generic computation of nuclear and magnetic small-angle neutron scattering observables of complex systems

Adams, M.P.; Michels, A.

doi:10.1107/S160057672600258X

Figure 9
Spin-flip SANS observables at the remanent state for three different ensembles of 800 iron nanoparticles with equal diameters of D = 40 nm (micromagnetic spin textures were simulated with MuMax3). Left column (a, b, c): dilute ensemble (single-particle case). (a) Representative particle with its internal spin texture color coded by m_x. (b) Corresponding two-dimensional spin-flip SANS cross section $[({\rm d}\Sigma_{{\rm sf}}/{\rm d}\Omega)(q_{y},q_{z})]$ showing a smooth intensity distribution that is characteristic of weak interparticle correlations. (c) Azimuthally averaged spin-flip intensity $[I_{{\rm sf}}(q)]$ displaying the expected sphere-like form factor oscillations (log–log scale). Middle column (d, e, f): moderately densely packed system. (d) Particles are positioned inside a supersphere with a volume fraction of $[\eta = 5\%]$ . The two-dimensional (e) and the one-dimensional (f) spin-flip SANS cross sections exhibit an increased statistical noise due to the disordered arrangement of the particles. Right column (g, h, i): simple cubic structure. (g) Particles are placed on a simple cubic lattice inside a supersphere (volume fraction: $[\eta = 30\%]$ ; center-to-center distance between spheres: 45 nm). (h) The two-dimensional spin-flip SANS cross section now shows emerging Bragg-peak-like features reflecting the underlying periodic packing. (i) $[I_{{\rm sf}}(q)]$ displays modulations and peak structures associated with these lattice correlations.

JOURNAL OF
APPLIED
CRYSTALLOGRAPHY

ISSN: 1600-5767

Volume 59| Part 3| June 2026| Pages 943-959

https://doi.org/10.1107/S160057672600258X

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