Experimental observation of magnetic poles inside
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Date
2014-12-15
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IOP Science
Abstract
The pole-avoidance principle of magnetostatics results in an angular anisotropy of the magnetic neutron scattering cross section dΣM dΩ. For the case of a sintered Nd–Fe–B permanent magnet, we report the experimental observation of
a ‘spike’ in dΣM dΩ along the forward direction. The spike implies the presence
of long-wavelength magnetization fluctuations on a length scale of at least
60 nm. Using micromagnetic theory, it is shown that this type of angular anisotropy
is the result of the presence of unavoidable magnetic poles in the bulk of
the magnet and is related to the q ≠ 0 Fourier modes of the magnetostatic field.
Thus, our observation proves the existence of such modes.© 2014 IOP Publishing Ltd and Deutsche Physikalische Gesellschaft.
Description
Keywords
Neutrons, Spin, Magnets, Anisotropy, Fourier analysis, Experiment planning
Citation
Périgo, E. A., Gilbert, E. P., Metlov, K. L. & Michels, A. (2014). Experimental observation of magnetic poles inside bulk magnets via Fourier modes of magnetostatic field. New Journal of Physics, 16(12), 123031. doi:10.1088/1367-2630/16/12/123031