A series of zinc-blende CdTe quantum dots in glass was investigated using Raman scattering and luminescence. The dot size was controlled by varying the annealing conditions. Luminescence was employed as a probe for quality of the sample and its adequacy for resonance. Resonant Raman spectra at the lowest confined energy levels of the quantum dots were obtained in function of the pressure in the range 1 bar to 4.6 GPa. The upper limit was established by a phase transition probably to NaCl structure, simultaneous with disappearance of Raman signal. In the latter phase, first-order Raman scattering is forbidden. The Grüneisen parameter for the LO phonon of CdTe quantum dots is given. ͓S0163-1829͑97͒04712-7͔

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Glass-ceramic material prepared with sugar cane bagasse ash as one of the raw materials was characterized to determine some important properties for its application as a coating material.X-ray diffraction patterns showed that wollastonite-2M (CaSiO 3 ) was the major glass-ceramic phase. The Rietveld method was used to quantify the crystalline (60 wt.%) and vitreous (40 wt.%) phases in the glass-ceramic. The microstructure (determined by scanning electron microscopy) of this material had a marble appearance, showing a microporous network of elongated crystals with some areas with dendritic, feather-like ordering. Microhardness data gave a mean hardness value of 564.4 HV (Vickers-hardness), and light microscopy disclosed a greenish brown colored material with a vitreous luster.

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