Angular Distribution of Photoelectrons Emitted from Copper Single Crystals

We measured the energy distribution of electrons emitted from a copper single crystal at 60° to the surface normal, using plane polarized light at normal incidence in the near uv region. Rotating the plane of polarization produced changes in the electron distribution between 5 and 28%. No such changes could be detected upon substituting a polycrystalline sample. The energy distribution of the single crystal differs considerably from that of the polycrystal. The results imply direct, $\overrightarrow{\mathrm{k}}$-conserving transitions and no scattering for a large fraction of those excited electrons which leave the crystal.