We have measured the attenuation of a supersonic helium beam scattered from the (001) surface of LiF as a function of surface temperature. We found that over an extended temperature range (140500 K) a simple model for the Debye-Waller factor can explain the data. At higher temperatures (500650 K) anharmonic effects become noticeable. Our data indicate that present models describing the Debye-Waller attenuation need improvements in this temperature range. The observed sudden drop of the He-beam reflected intensity at about 780 K is discussed in terms of surface disorder.
ASJC Scopus subject areas
- Condensed Matter Physics