Azimuthal angular dependence of LEED fine structure from Cu(001)

LEED fine structure from Cu(001) was measured as a function of energy for differing azimuth angles. The most prominent feature, associated with the emergence of the 11 beam, was most easily observed (best resolution and maximum intensity) when the incident beam was along the 〈11〉 azimuth. As the beam moved off this azimuth the resolution appeared to become worse. Also, no fine structure due to the 01, 10 emergences was observed when near the 〈11〉 direction. These observations can be understood in terms of the analysis made by Gaubert et al. [Surface Sci. 147 (1984) 162] and provide experimental evidence illustrating their findings. Another feature, associated with the 20 beam emergence, was seen when close to the 〈10〉 azimuth.