REVERSIBLE TEMPERATURE-DEPENDENCE IN SURFACE-ENHANCED RAMAN-SCATTERING OF 1-PROPANETHIOL ADSORBED ON A SILVER ISLAND FILM

Intensity of the surface-enhanced Raman scattering (SERS) of 1-propane thiol adsorbed on a silver film prepared chemically has been measured over the 15-300 K surface temperature range. A reversible change in th e SERS intensity with the temperature has been observed, with the inte nsity at 15 K being larger than that at 300 K by a factor of similar t o 3. Various factors that can affect the SERS intensity such as the la ser-induced change in surface morphology, adsorption and desorption, a nd destruction of adatoms could be eliminated as a possible cause for the observed temperature dependence. Enhancement of the Raman intensit y has been calculated over the experimental temperature range based on the electromagnetic (EM) model for SERS proposed by Gersten and Nitza n. It has been found that the observed temperature dependence can be e xplained qualitatively with the EM model calculation.