C. Duverger et al., RAMAN-SPECTROSCOPIC INVESTIGATIONS OF THE EFFECT OF THE DOPING METAL ON THE STRUCTURE OF BINARY TELLURIUM-OXIDE GLASSES, Journal of non-crystalline solids, 220(2-3), 1997, pp. 169-177
Raman studies over the range 10 to 1000 cm(-1) have been performed on
binary tellurium-oxide glasses (1 - x)TeO2-xMO (M = Pb, Zn or Mg) prep
ared using a conventional melt technique. The intensities and position
s of Raman bands observed in the range above 250 cm(-1) were found to
depend both on the compound oxide and on the amount of doping. indeed,
the ratio of the intensity of the band around 680 cm(-1) (assigned to
vibrations of TeO4 trigonal bipyramids) with respect to that of the c
omponent around 750 cm(-1) (related to stretching-vibrations in TeO3+1
, TeO3 and MO groups) are affected in different ways for the glass-mod
ifier MgO and for the intermediate glass-formers PbO and ZnO. Concurre
ntly, an explicit dependence on the compound oxide and amount of dopin
g was also observed on the maximum of the boson peak (BP) in the low-f
requency region around 40 cm(-1). The structural correlation lengths i
n the glasses, calculated using the model described by Shuker and Gamm
on, were found to be about 0.50 nm for (1 - x)TeO2-xMgO glasses and ar
ound 0.65 nm for (1 - x)TeO2-xMO (M = Pb or Zn) glasses. All these res
ults are interpreted in terms of the effect of the metal oxide on the
changes induced in the structural arrangements of (1)(infinity)[TeO4-T
eO3] chains. (C) 1997 Elsevier Science B.V.