Raman spectra and relaxation in amorphous naphthalene Original Research Article

Raman spectra were studied for naphthalene films prepared by vacuum deposition onto cold substrates. Films prepared at 7 and 25 K showed spectra similar to those of liquid, suggesting that they were amorphous. Structural relaxation due to stepwise elevation of the sample temperature was studied by monitoring the spectral evolution. Abrupt spectral changes which suggest that the sample underwent crystallization were observed around 105 K after a gradual increase of Raman intensity. This increase is discussed in connection with the change in structural coherence in the amorphous state.