2016 Volume 14 Pages 73-77
We have theoretically studied the azimuthal angular dependance of surface and bulk plasmon losses in Al 2s photoemission spectra. Here, full multiple scatterings of photoelectrons are taken into account before and after plasmon losses within the quantum Landau formula, which can describe overall features of the photoemission bands. By considering elastic scattering, the azimuthal angular dependence can be evaluated. Two types of peaks are observed; strong peaks attributed to forward focusing and weak peaks appeared as diffraction pattern. Forward focusing peaks are observed when atoms exists in the forward direction. The peak intensities from deeper layers are reduced by the defocusing effect. The origin of the weak peaks are discussed with the local geometric analysis. The differences of main, 1st bulk and surface plasmon loss are discussed.The peaks of diffraction pattern largely changed by increasing the photoelectron kinetic energy. [DOI: 10.1380/ejssnt.2016.73]
