α-uranium phase in compressed neodymium metal

Autor: Gary N. Chesnut, Yogesh K. Vohra
Rok vydání: 2000
Předmět:
Zdroj: Physical Review B. 61:R3768-R3771
ISSN: 1095-3795
0163-1829
Popis: The light rare-earth metal, neodymium, has been studied up to 155 GPa in a diamond-anvil cell using energy dispersive x-ray diffraction with a synchrotron source. The pressures were calibrated using copper as an internal x-ray pressure standard. A phase transformation from a monoclinic phase $(C2/m,$ $4\mathrm{a}\mathrm{t}\mathrm{o}\mathrm{m}\mathrm{s}/\mathrm{c}\mathrm{e}\mathrm{l}\mathrm{l})$ to an orthorhombic \ensuremath{\alpha}-U phase $(Cmcm,4\mathrm{a}\mathrm{t}\mathrm{o}\mathrm{m}\mathrm{s}/\mathrm{c}\mathrm{e}\mathrm{l}\mathrm{l})$ was observed at 113\ifmmode\pm\else\textpm\fi{}6 GPa without any observable volume collapse. The observation of \ensuremath{\alpha}-U phase in Nd and, previously, in cerium and praseodymium clearly establishes this phase in light rare-earth metals. Our equation of state measurements suggest that delocalization of the f shell in Nd occurs without any volume collapse unlike Ce and Pr.
Databáze: OpenAIRE