J. G. Barker

TL;DR: In this paper, two high-resolution, general-purpose, small-angle neutron scattering instruments have been constructed at the National Institute of Standards and Technology's Center for Neutron Research.

TL;DR: An ultra-high-resolution small-angle neutron scattering (USANS) double-crystal diffractometer (DCD) is now in operation at the NIST Center for Neutron Research (NCNR), which uses multiple reflections from large silicon (220) perfect single crystals, before and after the sample, to produce both high beam intensity and a low instrument background suitable for smallangle scattering measurements.

TL;DR: In this article, a method for analyzing field-dependent SANS data from such materials in terms of a model based on the theory of micromagnetics was explored. But the results suggest that the anisotropy may be strongly nonuniform in each crystallite, possibly due to twinning, and that some magnetic moments in the Ni samples are strongly pinned at defects.

TL;DR: The results for l(C) indicate that in Co the main source of nonuniformity in the spin system is the anisotropy field of each individual crystallite, whereas in nanocrystalline Ni the main sources of spin disorder originate from twin faults or from the defect cores of grain boundaries.

TL;DR: In this article, a method for determining the exchange-stiffness constant A of a ferromagnetic bulk material by field-dependent elastic small-angle neutron scattering (SANS) is presented.