Studies of the Rare-Earth Hydrides Technical Report Ⅶ CRYSTAL STRUCTURE OF THE RARE-EARTH METALS THE CRYSTAL STRUCTURE OF THE SAMPLES OF LANTHANUM, CERIUM, PRASEODYMIUM AND NEODYMIUM USED

摘要

It was a matter of interest to determine in which crystalline modifications the various rare earth metals used in this investigation were present. The metals lanthanum, cerium, and praseodymium have all been reported as existing in more than one modification. There has been some discussion concerning which of the possible allotropic modifications of these metals react more readily with hydrogen. A Knowledge of the structures and cell constants of the metal samples actually used would also give a more secure basis to discussions of changes undergone by the metals on forming the hydrides.