2019, Kovbasa, N., Graf, L., Knupfer, M.

We have investigated the charge carrier plasmon in the quasi one-dimensional metal TTF-TCNQ using electron energy-loss spectroscopy. Our data reveal a negative plasmon dispersion with a slope that is independent of temperature, which is in agreement to predictions from model calculations and previous room temperature data. A plasmon energy shift upon temperature is observed, and we discuss possible contributions to this shift. The spectral width of the plasmon is rather temperature independent, but increases clearly above a momentum value of about 0.3 Å-1.