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Magnetic Guinier law
- Source :
- 'IUCrJ ', vol: 7, pages: 136-142 (2020), IUCrJ, Vol 7, Iss 1, Pp 136-142 (2020), IUCrJ
- Publication Year :
- 2020
-
Abstract
- The Guinier law for magnetic SANS on bulk ferromagnets is introduced and applied to the analysis of nanocrystalline cobalt. The magnetic-field-dependent Guinier radius reflects the characteristic microstructural size and depends on the magnetic interactions.<br />Small-angle scattering of X-rays and neutrons is a routine method for the determination of nanoparticle sizes. The so-called Guinier law represents the low-q approximation for the small-angle scattering curve from an assembly of particles. The Guinier law has originally been derived for nonmagnetic particle-matrix-type systems and it is successfully employed for the estimation of particle sizes in various scientific domains (e.g. soft-matter physics, biology, colloidal chemistry, materials science). An important prerequisite for it to apply is the presence of a discontinuous interface separating particles and matrix. Here, the Guinier law is introduced for the case of magnetic small-angle neutron scattering and its applicability is experimentally demonstrated for the example of nanocrystalline cobalt. It is well known that the magnetic microstructure of nanocrystalline ferromagnets is highly nonuniform on the nanometre length scale and characterized by a spectrum of continuously varying long-wavelength magnetization fluctuations, i.e. these systems do not manifest sharp interfaces in their magnetization profile. The magnetic Guinier radius depends on the applied magnetic field, on the magnetic interactions (exchange, magnetostatics) and on the magnetic anisotropy-field radius, which characterizes the size over which the magnetic anisotropy field is coherently aligned into the same direction. In contrast to the nonmagnetic conventional Guinier law, the magnetic version can be applied to fully dense random-anisotropy-type ferromagnets.
- Subjects :
- guinier law
Field (physics)
micromagnetics
Physics [G04] [Physical, chemical, mathematical & earth Sciences]
FOS: Physical sciences
magnetic scattering
02 engineering and technology
anisotropy
Neutron scattering
01 natural sciences
Biochemistry
Magnetization
Condensed Matter::Materials Science
ferromagnets
Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
0103 physical sciences
General Materials Science
010306 general physics
lcsh:Science
Physics
small-angle neutron scattering
Condensed Matter - Mesoscale and Nanoscale Physics
Scattering
General Chemistry
nanoscience
021001 nanoscience & nanotechnology
Condensed Matter Physics
Magnetostatics
Research Papers
Magnetic field
Magnetic anisotropy
Ferromagnetism
Physique [G04] [Physique, chimie, mathématiques & sciences de la terre]
Law
magnetic materials
Condensed Matter::Strongly Correlated Electrons
lcsh:Q
0210 nano-technology
Subjects
Details
- Language :
- English
- Volume :
- 7
- Database :
- OpenAIRE
- Journal :
- IUCrJ
- Accession number :
- edsair.doi.dedup.....7a5167381fbf9feef236f71eaf57c939