Distribution of boundary planes in a (La_0.67Nd_0.33)B₆polycrystalline bulk prepared by spark plasma sintering

Abstract

The electron backscatter diffraction approach and five parameter analysis method are used to investigate the orientation textures of boundary planes in a IJLa 0.67 Nd 0.33 )B 6 polycrystalline bulk prepared by spark plasma sintering. While the entire boundaries overall favour the {001} orientation, the orientation textures of various boundary planes are not homogeneous. If divided by the boundary type, the LaB 6 /LaB 6 grain boundary planes favour the {001} orientation, the NdB 6 /NdB 6 grain boundary plane orientation approaches the {011} position, and the LaB 6 /NdB 6 phase boundary planes favour the {011} orientation. If divided by the misorientation angle, boundaries with a misorientation angle lower than 10°favour the {011} orientation and boundaries with a misorientation angle higher than 10°favour the {001} orientation. Possible origins of the anisotropic distribution of boundary planes are analyzed. The potential effects of anisotropy in boundary plane distributions on electron emissivity are also suggested.

Grain boundary plane distribution and its potential correlation with magnetic properties in hexagonal RCo5 permanent magnets

“…Here, the connection might tentatively be called "grain boundary magnetism distribution" (GBMD) because it takes the orientation texture between crystals into account. The misorientation in RCo 5 permanent magnets has been proven to be inhomogeneous, [3][4][5][6] and the authors hereby further propose the principle of "concrete analysis to concrete boundary planes" during GBPD studies. Some important examples are as follows:…”

“…Therefore, the major motivation for this work is to provide a better description and increased understanding about the potential effect of grain boundary plane distribution (GBPD) on magnetic properties. Recently, we have reported the orientation texture of boundary planes in hexagonal RCo 5 permanent magnets (with relatively weak orientation texture of crystals), [3][4][5][6] and we now report new computational developments in this inter-disciplinary work.…”

Crystallographic orientation-dependent magnetic properties of a PrCo5permanent magnet prepared by hot deformation

“…When the three Eulerian angle parameters are disregarded (that is, averaged over all misorientations), the λ(n) has a two-dimensional quantity and presents the preferential distribution of habit planes. 14,[31][32][33][34][35][36] In the current work, the orientation texture of habit planes was plotted after the entire boundaries were filtered into partitions with specific misorientation angle ranges. We also note that for the hexagonal symmetries, to make the analysis reliable, the FPA method requires 2 × 10 5 line segments for a five-dimensional analysis and needs 2 × 10 3 line segments for a two-dimensional analysis.…”

Orientation texture of local habit planes and its relevance to local magnetic performance in a hot deformed PrCo5bulk permanent magnet

“…No new experimental work is included in this section, the new computational as well as the analytic work could be taken as the benecial extension of our previous report. 22,23 In our previous work, 22 the 27.796 /[0001] misorientation relationship (or in a coincidence site lattice (CSL) nomination, the S13a boundary) has been found to be remarkably preferred in SmCo 5 magnet (which has quite similar lattice structure with PrCo 5 ), and (0001) planes are more populous in the more highly deformed samples than in the less deformed samples. Our previous work 23 has also revealed the feasibility to accurately lter the boundaries according to the misorientation relationship across the boundaries.…”

“…22,23 In our previous work, 22 the 27.796 /[0001] misorientation relationship (or in a coincidence site lattice (CSL) nomination, the S13a boundary) has been found to be remarkably preferred in SmCo 5 magnet (which has quite similar lattice structure with PrCo 5 ), and (0001) planes are more populous in the more highly deformed samples than in the less deformed samples. Our previous work 23 has also revealed the feasibility to accurately lter the boundaries according to the misorientation relationship across the boundaries. These developments spontaneously present the potential pathway to control the local magnetic anisotropy via locally obtaining boundaries with particular misorientation relationships.…”