Vibrational property study of SrGa2H2 and BaGa2H2 by inelastic neutron scattering and first principles calculations.
Vibrational properties of the gallium hydrides SrGa2H2 and BaGa2H2 have been investigated by means of inelastic neutron scattering (INS) and first-principles calculations. The compounds contain Ga-H units being part of a two-dimensional polyanionic layer, [(GaH)(GaH)]2-. The INS spectra are composed of dispersed internal Ga-H bending and stretching modes at frequencies above 600 cm(-1) and external lattice modes at frequencies below 220 cm(-1). Frequencies of the internal modes are not susceptible to the metal countercation, indicating a strong integrity of the polyanionic layer as a building unit in the structures of SrGa2H2 and BaGa2H2. The Ga-H stretching modes have frequencies between 1200 and 1400 cm(-1), which is very low compared to molecular gallium hydrides. The weak Ga-H bond in SrGa2H2 and BaGa2H2 is balanced by Sr(Ba)-H interactions.
Lee
Myeong H
MH
Department of Physics, Arizona State University, P.O. Box 871504 Tempe, Arizona 85287-1504, USA.
Evans
Michael J
MJ
Daemen
Luke L
LL
Sankey
Otto F
OF
Häussermann
Ulrich
U