Magnetic field dependent small-angle neutron scattering on a Co nanorod array: evidence for intraparticle spin misalignment

Autor: Jens-Peter Bick, Artem Feoktystov, Andreas Michels, Dirk Honecker, Andreas Tschöpe, Philipp Szary, R. Birringer, Annegret Günther, Uwe Keiderling, Charles Dewhurst
Rok vydání: 2014
Předmět:
Zdroj: Journal of Applied Crystallography
Journal of applied crystallography 47(3), 992-998 (2014). doi:10.1107/S1600576714008413
'Journal of Applied Crystallography ', vol: 47, pages: 992-998 (2014)
ISSN: 1600-5767
DOI: 10.1107/s1600576714008413
Popis: The results of magnetic field dependent small-angle neutron scattering measurements on a cobalt nanorod array are reported. The data provide evidence for the existence of intraparticle spin disorder.
The structural and magnetic properties of a cobalt nanorod array have been studied by means of magnetic field dependent small-angle neutron scattering (SANS). Measurement of the unpolarized SANS cross section dΣ/dΩ of the saturated sample in the two scattering geometries where the applied magnetic field H is either perpendicular or parallel to the wavevector k i of the incoming neutron beam allows one to separate nuclear from magnetic SANS, without employing the usual sector-averaging procedure. The analysis of the SANS data in the saturated state provides structural parameters (rod radius and centre-to-centre distance) that are in good agreement with results from electron microscopy. Between saturation and the coercive field, a strong field dependence of dΣ/dΩ is observed (in both geometries), which cannot be explained using the conventional expression of the magnetic SANS cross section of magnetic nanoparticles in a homogeneous nonmagnetic matrix. The origin of the strong field dependence of dΣ/dΩ is believed to be related to intradomain spin misalignment, due to magnetocrystalline and magnetoelastic anisotropies and magnetostatic stray fields.
Databáze: OpenAIRE
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