Electronic excitations in SnS2: An electron-energy-loss-spectroscopy study.

A reflection-electron-energy-loss spectroscopy study of 2H-SnS 2 single crystals is presented. Low-energy losses, traditionally attributed to single-electron transitions, are shown here to be of a collective character. Their interpretation as collective eigenmodes of a multiplasma electronic system is demonstrated with the aid of a simplified two-plasma model, which yields a remarkably good agreement with the experimental data. Within this framework, some of the distinct differences between the various mode are emphasized