HOLZ Rings in EBSD Patterns of the UFeB4 Compound: Association with a Random Distribution of Planar Defects
Abstrakt
The UFeB4 phase present in different alloys of the B-Fe-U system was studied by powder X-ray diffraction (PXRD) and scanning electron microscopy complemented with energy-dispersive spectroscopy and electron backscattered diffraction (EBSD). The PXRD data showed that the ternary compound crystallized adopting essentially the YCrB4-type structure.
However, microstructural observations revealed that under high undercooling conditions the UFeB4 phase exhibits a random distribution of defects parallel to, which are consistently associated with intense higher-order Laue zone rings in EBSD patterns. Indexation of the EBSD patterns showed that the defective structure is compatible with an intergrowth of YCrB4- and ThMoB4-type layers according to the (010)(YCrB4)//(1 (1) over bar0)(ThMoB4) and [001](YCrB4)//[001](ThMoB4) orientation relation previously reported for an analogous compound.
Magnetic studies indicated that the annealed UFeB4 compound has a paramagnetic behavior in the 2-300 K temperature range.