Raman spectroscopy of glasses in the As-Te system

For the first time, the Raman spectra of AsxTe1-x glasses, 0.2 <= x <= 0.6, have been measured over the entire glass-forming range. The spectra exhibit three broad spectral features attributed to vibrations of structural units having Te-Te, As-Te and As-As bonds. The observed chemical disorder in the glasses is discussed on the basis of partial bond fractions derived from the integrated intensity of the Raman modes. The underlying structural model suggests a dissociation of AsTe- or As2Te3-related units in the glass melt. The spectra of glasses quenched from different temperatures, as well as those of the annealed vitreous alloys, are consistent with predictions of the model. (C) 2012 Elsevier Inc. All rights reserved.