The Raman spectra of nanometer-sized particles of SnO2 (3–90 nm) at room temperature are reported. In the Raman spectra of the particles of SnO2, which are quite different from that of single-crystal SnO2, there appear two new characteristic peaks, and their intensities decrease gradually with the increase of crystal size. It is concluded that the new peaks can be explained by the surface phonon modes of nanometer SnO2, consequently there is a relation between the structures of surface layers and bulk. It is believed that it is possible to determine the exact positions of atoms in surface layers of some nanometer crystals from their laser Raman spectra.

Composition dependence of Cu-In-Se films with nominal 60 nm thickness grown on Na-free glass substrates has been systematically investigated by Raman scattering and x-ray diffraction spectra. The most intense A 1 mode shift from 175 cm −1 for Cu 1.5 InSe 2 to 151 cm −1 for CuIn 5 Se 8 indicates weakening of the bond-stretching forces with decrease in Cu content. According to the evolution of the phonon frequencies in films, we found that the Raman bands around 160 and 174 cm −1 observed in CuIn 5 Se 8 are probably due to the other ordered structure phase which is very similar to chalcopyrite-related CuIn 5 Se 8 . Such coexistence mechanism of both structure phases should be associated with the influence of preferred (112) orientation in the films. Comparing our experimental data with the reported data of the related compounds, we explain the composition effect on phonon frequencies shift from Cu-rich to Cu-poor transition in this paper.

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Shards from the archaeological site of Xishan (Henan, China) were analyzed by Raman microscopy to determine the pigments used in the decoration of this ancient (ca 4300-2800 BC) pottery. It was found for the first time that anatase was used for white coating 5000 years ago and this represents a contribution to the current knowledge of the history of pigments. The brown coating was identified as graphite. The red and black coatings were mainly haematite and magnetite; the colour of the coatings depends on the ratio of haematite to magnetite.

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