ELECTRONIC SURFACE RESONANCE BAND-STRUCTURE AND LINESHAPES

Electronic surface resonances are quasistationary surface states at energies above the vacuum level. They may be observed as narrow intensity fluctuations in LEED and other electron scattering experiments. A survey of recent developments in the measurement and interpretation of low-energy surface resonance band structure E (k// parallel (E equals resonance energy, k// parallel equals reduced surface-parallel momentum) is presented. The importance of analyzing resonance lineshapes for accurate determination of resonance levels is emphasized, and high-resolution LEED data for W(001) surface is analyzed as an example.