Compacted discs prepared from a mixture of finely divided particles of a compound diluted in a large excess of metal powder facilitate the measurement of Raman spectra for some compounds which give poor scattering by conventional techniques. The method is most useful with coloured compounds. The advantages include simplicity, increased signal-to-noise ratio by factors of up to 1000 and decreased or altered fluorescence. The effect appears to be caused mainly by small crevices in the compacted metal surface which act as internal mirrors to produce many small multiple-reflection cells, but there is also evidence of an electronic interaction with the metal surface. Silver, aluminium and copper matrices were studied, silver being found to be the most advantageous, although aluminium under certain conditions may also be effective.
- compacted metal discs
- measuring Raman-spectra