Abstract
High-resolution time-of-flight measurements of 17-meV He atoms scattered from an Ag(111) surface along the and azimuths are reported. Most of the spectra reveal two sharp peaks and from their locations dispersion curves have been determined out to the zone boundary. The agreement of the lower-frequency mode with the theoretical Rayleigh dispersion curve is excellent. The other mode is significantly lower (35%) than the calculated longitudinally polarized surface mode.
- Received 6 April 1983
DOI:https://doi.org/10.1103/PhysRevLett.51.578
©1983 American Physical Society