SERS on carbon chain segments: monitoring locally surface chemistry

Carbon films deposited (at elevated temperatures) on SERS active metal subs trates show remarkable fluctuations in Raman spectra, if a Raman microscope is used. In subsequently recorded spectra distinct sets of intense, but ra ther narrow Raman lines appear, which are related to vibrations of correspo nding carbonaceous groups. These spectral fluctuations evidence an enduring surface chemistry producing a variety of carbon chain configurations, whic h get temporarily in contact with metal sites, the so-called 'hot spots', t hat exhibit extremely large surface enhancements. (C) 2000 Elsevier Science B.V. All rights reserved.