VIBRATIONAL-MODES OF HYDROGEN AND DEUTERIUM AT INP(110) SURFACES

Vibrations at hydrogen- and deuterium-covered InP(110) surfaces were i nvestigated by high-resolution electron energy-loss spectroscopy. With semi-insulating crystals, In-H and P-D bending modes were found at 43 8 and 465 cm(-1) (54.3 and 57.7 meV), respectively. In the low-coverag e regime two components of the P-H stretching vibration at 2260 and 23 00 cm(-1) (280.2 and 285.4 meV) are resolved. They are explained by vi brational motions of mono- and dihydride groups. This indicates that I nP(110) surfaces are disrupted even after small H exposures. Bond stre ngths are estimated from the isotope shifts of the stretching frequenc ies.