Limitations in specular beam leed analysis due to measurement of the scattering angle: Examples from a study of Cu(110)

The I–V profiles for specular LEED beams from a clean Cu(110) surface have been measured for three selected angles of incidence of the primary electron beam with respect to the crystal orientation. A comparison of experimental and calculated profiles indicates that the first interlayer spacing is contracted by 8 ± 3%, a value in reasonable agreement with the result obtained by a previous study of non-specular beams. However, this study demonstrates some inherent limitations of LEED analyses due to difficulties in the precise measurement of the alignment of the primary electron beam.