Ein allgemeiner Vierscheitelsatz für ebene Jordankurven

Ohne Zusammenfassung     

Über gewisse lineare Transformationen

Ohne Zusammenfassung     

Plasmon dispersion in Al atk≦k F using electron energy loss spectroscopy

We find a quasi quadratic dispersion of the plasmon up to _p = 28 eV atk=1.77 Å^–1 with no levelling off contrary to other measurements. We usedk-scans at constant energy loss andE-scans at constant wave vector, which yield different dispersions of the plasmon peak maximum because of the finite halfwidth. The levelling off in plasmon dispersion observed previously is due to multiple scattering events, which obscure the plasmon dispersion inE-scans.We confirmed the anisotropy of the dispersion coefficient by investigating polycrystalline samples of different orientation.     

Surface enhanced Raman scattering (SERS): Annealing the silver substrate

Silver films, deposited at 120 K in UHV, were slowly warmed to room temperature, Characteristic intensity variations of the inelastic background (I), of disorder induced Raman scattering from phonons (II) and of the SERS signal from adsorbed pyridine have been observed. In the case of (I) and (II) these are explained by the bulk concentration of point defects, in the SERS case by annealing of atomic scale surface roughness.