Isotope effect in a Cu-H(D) system with hexagonal hydride phase

The decomposition pressure P-dec of copper deuteride has been experimentally determined in a diamond anvil cell. The value of 6.8 +/- 0.6 GPa is lower than the corresponding pressure of copper hydride. The difference between standard Gibbs energies of decomposition of copper hydride and deuteride has been calculated as equal to -5.2 kJ mol(-1) (H-2). The zero-point energy of hydrogen vibration in the hydride lattice has been obtained applying the localized harmonic oscillator model. (c) 2005 Elsevier B.V. All rights reserved.