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Nearly lattice-matched ZnS x Se 1-x (0 ≤ x < 0.1) grown heteroepitaxially on (001) GaAs substrates was studied by Raman spectroscopy. We observed clearly Raman scattering on the plasmon-longitudinal optical (LO) phonon coupled mode at the GaAs side of the ZnS x Se 1-x -GaAs interfacial region under suitably polarised exciting light, i.e. light with electric field perpendicular to the [110] crystallographic axis. By the systematical study of Raman scattering on the coupled mode as a function of S substitution we found a clear correlation between the plasmon-LO phonon coupling strength and the lattice match. At the well-matched grown epilayer, ZnS 0.06 Se 0.94 , the Raman scattering on the plasmon-LO phonon coupled mode appears to be strongest.

Selected ancient Vietnamese (proto)porcelains and celadons (13–16th centuries) from the Ha Lan (Nam Ð inh), Chu Ðâu (Nam Sach, Hai Duong) and Hop Le (Binh Giang, Hai Duong) ceramic kilns were studied by chemical analysis, macro- and micro-Raman spectroscopy, thermal expansion and differential thermal analysis. Raman spectra of quartz, cristobalite, rutile, mullite, anatase, iron oxide, amphibole and glassy phases were analysed and their evolutions are used to discuss the ancient ceramic technology (raw materials used, firing procedures of the glaze and body, etc.). Structural composition data taken from thermal expansion measurements and Raman spectroscopy are in good agreement. Particular attention is given to the analysis of glaze for the feasible discrimination between original artefacts and modern copies. On the basis of experimental results, the samples made at Chu Ð au can be considered as true porcelains, whereas those made at Hop Le and Ha Lan had evolutions towards porcelain and high-temperature-fired fine faience, respectively. Copyright © 2000 John Wiley & Sons, Ltd.