TY  - JOUR
AU  - Titov, Ivan
AU  - Barbieri, Massimiliano
AU  - Bender, Philipp
AU  - Peral, Inma
AU  - Kohlbrecher, Joachim
AU  - Saito, Kotaro
AU  - Pipich, Vitaliy
AU  - Yano, Masao
AU  - Michels, Andreas
TI  - Effect of grain-boundary diffusion process on the geometry of the grain microstructure of Nd − Fe − B nanocrystalline magnets
JO  - Physical review materials
VL  - 3
IS  - 8
SN  - 2475-9953
CY  - College Park, MD
PB  - APS
M1  - FZJ-2019-05189
SP  - 084410
PY  - 2019
AB  - 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.
LB  - PUB:(DE-HGF)16
UR  - <Go to ISI:>//WOS:000480695600004
DO  - DOI:10.1103/PhysRevMaterials.3.084410
UR  - https://juser.fz-juelich.de/record/865912
ER  -