Distribution of boundary planes in a (La0.67Nd0.33)B6 polycrystalline 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 (La_0.67Nd_0.33)B₆ 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 LaB₆/LaB₆ grain boundary planes favour the {001} orientation, the NdB₆/NdB₆ grain boundary plane orientation approaches the {011} position, and the LaB₆/NdB₆ 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.