%0 Journal Article
%A Titov, Ivan
%A Barbieri, Massimiliano
%A Bender, Philipp
%A Peral, Inma
%A Kohlbrecher, Joachim
%A Saito, Kotaro
%A Pipich, Vitaliy
%A Yano, Masao
%A Michels, Andreas
%T Effect of grain-boundary diffusion process on the geometry of the grain microstructure of Nd − Fe − B nanocrystalline magnets
%J Physical review materials
%V 3
%N 8
%@ 2475-9953
%C College Park, MD
%I APS
%M FZJ-2019-05189
%P 084410
%D 2019
%X Hot-deformed anisotropic Nd−Fe−B nanocrystalline magnets have been subjected to the grain-boundary diffusion process (GBDP) using a Pr70Cu30 eutectic alloy. The resulting grain microstructure, consisting of shape-anisotropic Nd−Fe−B nanocrystals surrounded by a Pr−Cu-rich intergranular grain-boundary phase, has been investigated using unpolarized small-angle neutron scattering and very small-angle neutron scattering. The neutron data have been analyzed using the generalized Guinier-Porod model and by computing, model independently, the distance distribution function. We find that the GBDP results in a change of the geometry of the scattering particles: In the small-q regime, the scattering from the as-prepared sample exhibits a slope of about 2, which is characteristic for the scattering from two-dimensional platelet-shaped objects, while the GBDP sample manifests a slope of about 1, which is the scattering signature of one-dimensional elongated objects. The evolution of the Porod exponent indicates the smoothing of the grain surfaces due to the GBDP, which is accompanied by an increase of the coercivity.
%F PUB:(DE-HGF)16
%9 Journal Article
%U <Go to ISI:>//WOS:000480695600004
%R 10.1103/PhysRevMaterials.3.084410
%U https://juser.fz-juelich.de/record/865912