MICROSTRUCTURAL STUDY OF RARE-EARTH INTERMETALLIC SINGLE-CRYSTALS BY TRANSMISSION ELECTRON-MICROSCOPY

[摘要] Single crystals of RAl2 and RFe1.95 (R=rare earth) have been studied by transmission electron microscopy. It is found that CeAl2 single crystal contains a few dendritic secondary phases and many {001} growth faults. Analysis suggests that the growth faults could result from the coalescence of vacancies, which was possibly enhanced by the compositional deviation from stoichiometry. However, a TbAl2 single crystal contains a number of large {111} planar faults enriched in tungsten induced by crucible contamination. By substituting 1 at.% Tb with Ho, the existence of tungsten changed from planar to small spherical particles. Studies on a pseudo-single crystal of (Tb0.27Dy0.73)Fe1.95 show numerous {111} stacking faults and many Widmanstatten precipitates. The influence of these crystal lattice imperfection and impurities on the magnetic behaviour is discussed.

[发布日期] 1994-06-01

[效力级别]  Proceedings Paper