Europium–Hydrogen Bond Distances in Saline Metal Hydrides by Neutron Diffraction

Authors

  • Klaus Yvon Laboratoire de Cristallographie, Université de Genève, 24 Quai Ernest Anserrnet, CH-1211 Genève 4
  • Holger Kohlmann
  • Bernard Bertheville

DOI:

https://doi.org/10.2533/chimia.2001.505

Keywords:

Crystal structures, Metal hydrides, Neutron diffraction, Rare-earth compounds, Synchrotron x-ray diffraction

Abstract

Europium–hydrogen bond distances in saline metal hydrides have been refined from neutron powder diffraction data on the magnesium-based ternary deuterides EuMg2D6, EuMgD4, Eu2MgD6, Eu6Mg7D26 and Eu2Mg3D10. Absorption effects were attenuated by choosing neutron energies close to the minimum absorption cross section of natural isotope mixtures of europium and by using annular sample holders on high-flux neutron diffractometers. Some structures required joint refinements of neutron and synchrotron diffraction data. The Eu-D distances found for the various coordination numbers of europium range between 237–276 pm (CN=9), 220–287 pm (CN=10), 239–287 pm (CN=11) and 228–299 pm (CN=12). They are closely similar to, but shorter by about 4 pm than the corresponding Sr–D distances in strontium analogues, thus underlining the analogy between the europium and alkaline-earth hydride chemistry.

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Published

2001-06-27

How to Cite

[1]
K. Yvon, H. Kohlmann, B. Bertheville, Chimia 2001, 55, 505, DOI: 10.2533/chimia.2001.505.