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Polarized small‐angle neutron scattering study of two‐dimensional spatially ordered systems of nickel nanowires
Author(s) -
Grigoryeva N. A.,
Grigoriev S. V.,
Eckerlebe H.,
Eliseev A. A.,
Lukashin A. V.,
Napolskii K. S.
Publication year - 2007
Publication title -
journal of applied crystallography
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.429
H-Index - 162
ISSN - 1600-5767
DOI - 10.1107/s0021889807005559
Subject(s) - scattering , condensed matter physics , biological small angle scattering , small angle neutron scattering , wide angle x ray scattering , magnetization , neutron scattering , small angle scattering , neutron diffraction , bragg peak , bragg's law , polarization (electrochemistry) , physics , nanowire , magnetic field , materials science , optics , diffraction , chemistry , beam (structure) , quantum mechanics
The magnetic and structural properties of two‐dimensional spatially ordered systems of ferromagnetic nickel nanowires embedded into an Al 2 O 3 matrix have been studied using polarized small‐angle neutron scattering (polarized SANS). We measured the total (nuclear and magnetic) scattering I ( q ) as a polarization‐independent scattering, the field‐dependent scattering as I H ( q ) = I( q , H ) − I ( q , 0), where H is the magnetic field, and the nuclear‐magnetic interference as a polarization‐dependent ( P ) scattering Δ I ( q , P ). A typical scattering pattern is composed of the diffuse small‐angle scattering and the Bragg peak. It is shown that the introduction of Ni into the matrix does not change the position of the Bragg peak but results in an increase of the scattering intensity both in the small‐angle region and at the Bragg positions. An external magnetic field was applied perpendicular or parallel to the long dimension of the nanowires in order to reveal the anisotropic properties of the magnetic system. It is shown that, firstly, the magnetic‐field‐dependent scattering I H ( q ) provides new and principally different information as compared with the interference term Δ I ( q ). Secondly, two contributions to the interference term Δ I ( q ) (ascribed to the diffuse scattering and to the diffraction peaks) have different signs indicating different origins of the scattering objects. Thirdly, polarized SANS gives a detailed picture of the magnetization process, which could not be obtained by methods of standard magnetometry.