Eur. Phys. J. D 19, 333-337 (2002)
https://doi.org/10.1140/epjd/e20020080

Evidence for a cubic-to-icosahedral transition of quasi-free Pd–H-clusters controlled by the hydrogen content

On the phase transitions in Pd–H-clusters

¹ Institute of Materials Physis, University of Göttingen, 37073 Göttingen, Germany
² Darmstadt University of Technology, Institute of Materials Science, 64287 Darmstadt, Germany
³ Max-Planck-Institut für Kohlenforschung, 45470 Mühlheim, Germany
⁴ Department of Physics, Birzeit University, P.O. Box 14, Birzeit, Palestine

Received: 15 October 2001
Revised: 7 February 2002
Published online: 15 June 2002

Abstract

An in situ synchrotron radiation study of quasi-free five nanometer-sized palladium clusters during hydrogen absorption is combined with molecular dynamics simulations to investigate the structural development. In the diffraction patterns, strong intensity changes are found that provide evidence for a structural phase transformation that is significantly different from the α––Pd–H bulk phase transition. The structural transition is reversible and driven by the hydrogen concentration. The intensity changes are consistent with a cubic-to-icosahedral structural phase transition obtained in molecular dynamical simulations using embedded-atom-method potentials.