Observation of plasmons in 2-D organic metal BO2.4I3 by reflection spectroscopy

For the first time the plasmon in 2-D organic metal BO 2,4 I 3 was observed by means of reflection method. The new unknown peak in the near-infrared region at 5000 cm -1 was observed in the specular reflection normal to the (101) crystal face, which makes an angle of 67 0° with the conducting sheet. Such spectrum can be theoretically simulated using the principal dielectric function for a two-dimensional metal The simulated spectrum agrees well with the experimental one, proving that this new peak is due to the plasmon absorption. Similar plasmon absorption we have observed for BO 2 Cl(H 2 O) 3 crystal.