Hydride Formation in the Intermetallic Compounds CePd3and CeRh3

Autor: Horst P. Beck, Frank Müller, Klaus Stöwe, Holger Kohlmann, Arturas Zalga
Rok vydání: 2009
Předmět:
Zdroj: Zeitschrift für anorganische und allgemeine Chemie. 635:1407-1411
ISSN: 1521-3749
0044-2313
DOI: 10.1002/zaac.200801356
Popis: The intermetallic compounds CePd3 and CeRh3 were hydrogenated at hydrogen pressures up to 24 MPa and temperatures up to 540 K, and investigated by X-ray and neutron powder diffraction and X-ray photoelectron spectroscopy (XPS). Both compounds retain their AuCu3 type arrangement upon hydrogen uptake. The cubic lattice parameters increase from 412.5(1) and 402.57(2) pm in CePd3 and CeRh3, respectively, to 413.5(1) and 406.27(3) pm in the corresponding hydrides. In contrast to the rhodium compound CePd3Hx forms only under high pressure and room temperature and releases hydrogen quickly in air. From neutron powder diffraction on CeRh3D0.84 deuterium atoms were found to occupy 84.4(8) % of octahedral interstices formed solely by rhodium atoms, [Rh6], in a statistical fashion, resulting in a deficient cubic anti-perovskite type structure (space group (No. 221), a = 407.248(7) pm at T = 299(2) K). Rhodium-deuterium (203.62(1) pm) and cerium-deuterium distances (352.69(1) pm) are consistent with typical interatomic distances in other hydrides. XPS measurements reveal mixed valency in CePd3.
Databáze: OpenAIRE
Externí odkaz: