Neutron spectroscopy of gamma manganese hydride

The vibrational spectrum of fcc gamma-MnH0.41 synthesized under high pressu re of gaseous hydrogen was studied by inelastic neutron scattering at 2 K i n the range of energy transfers from 25 to 400 meV. The fundamental band of optical hydrogen vibrations consists of a peak at 111 meV with a broad sho ulder towards higher energies, which extends up to about 140 meV. At higher energy transfers, the spectrum originates from multiphonon neutron scatter ing and exhibits approximately harmonic behaviour. The results are compared with the available data for other metal hydrides. (C) 2000 Elsevier Scienc e Ltd. All rights reserved.