Plasmon spectrometry is an important method to obtain information on many-body effects in the solid state. The plasmon halfwidth and the dispersion coefficient are well investigated for a number of materials, and compare well with quantum mechanical predictions. The excitation strength of the coherent double plasmon has been investigated to a lesser extent. Experimental results are at variance with one another and with theory. This is partly due to the plural scattering which masks the coherent double plasmon.
Accurate analysis of plasmon spectra requires not only to remove the inelastic plural processes but also to take into account the coupling between Bragg and plasmon scattering at high scattering angles. It is shown that the excitation strength of the coherent double plasmon in forward direction falls below the detection limit when this correction is applied.
Schattschneider, P.; Su, D. -S.; and Pongratz, P.
"Influence of Bragg Scattering on Plasmon Spectra of Aluminum,"
Scanning Microscopy: Vol. 6
, Article 8.
Available at: https://digitalcommons.usu.edu/microscopy/vol6/iss1/8