Structur Factor of magnetic spin misalignment (Trac #726)

[sasview-bot]

There exist magnetic structure factor model describing the magnetic misalignment in a ferromagnetic bulk material arising from particle with magnetocristalline anisotropy. Moreover there exist another magnetic structure factor decribing spin canting due to magnetostatic dipolar fields around mmagnetic inhomogeneities. See A. Michels, Magnetic small-angle neutron scattering of bulk ferromagnets, J. Phys.: Condens. Matter 26, 383201 (2014) (and references therein).

Migrated from http://trac.sasview.org/ticket/726

{
    "status": "new",
    "changetime": "2019-03-03T01:20:34",
    "_ts": "2019-03-03 01:20:34.649200+00:00",
    "description": "There exist magnetic structure factor model describing the magnetic misalignment in a ferromagnetic bulk material arising from particle with magnetocristalline anisotropy. Moreover there exist another magnetic structure factor decribing spin canting due to magnetostatic dipolar fields around mmagnetic inhomogeneities. See A. Michels, Magnetic small-angle neutron scattering of bulk ferromagnets, J. Phys.: Condens. Matter 26, 383201 (2014) (and references therein).",
    "reporter": "dirk",
    "cc": "",
    "resolution": "",
    "workpackage": "SasModels New Model",
    "time": "2016-10-07T15:37:51",
    "component": "sasmodels",
    "summary": "Structur Factor of magnetic spin misalignment",
    "priority": "major",
    "keywords": "",
    "milestone": "sasmodels Next Release +1",
    "owner": "dirk",
    "type": "enhancement"
}

[butlerpd]

Trac update at 2019/03/03 01:20:34: butler changed type from "task" to "enhancement"

[dehoni]

Here are some test data and the associated mathematica notebook. The same material parameters as in Michels et al. PRB 94, 054424 (2016) Effect of Dzyaloshinski-Moriya interaction on elastic small-angle neutron scattering. The data reproduce Fig6 or Eq 49 of the spin-flip difference cross-section for nonuniform spin textures around crystalline imperfections.
test data_SFchi.zip

[dehoni]

Attached are test data and the creating mathematica notebook reproducing the results for the magnetic misalignment scattering for unpolarised neutrons shown in Fig3 of Honecker and Michels, PRB 87,224426 (2013). The spin-misalignment is the scattering cross section after substracting the residual scattering at a saturating magnetic field.
testdata_Michels_Honecker_2013.zip

[dehoni]

The models for the field-dependent scattering of bulk ferromagnets (with and without subtracting the reference state at saturation) have been published also on the Model Marketplace.
Micromagnetic_Models_Ferromagnet.zip and the image showing the magnetic different magnetic spin structures:

[dehoni]

In the next step, this model will be used to check the general scattering calculator for micromagnetic simulations. The results should coincide for same structural parameters in the approach to saturation (see e.g. Fig3 in Honecker et al. PRB 88, 094428 (2013)).

[dehoni]

The data should be transfered to test folder and a tutorial produced, e.g. comparing the experimental data to simulation results and Generic Scattering Calculator.