J. Dexpertghys et al., INVESTIGATION BY RAMAN-SCATTERING OF THE [TEO2-RMO0.5] (M=AG OR TL) GLASSES AND OF THE RELATED IONIC CONDUCTORS [TEO2-RMO0.5](1-X)[AGI]X, Journal of non-crystalline solids, 170(2), 1994, pp. 167-174
The structure of binary glasses [TeO2-RMO0.5], with M = Tl (or Ag) and
0.22 less-than-or-equal-to R less-than-or-equal-to 1 (0.28 less-than-
or-equal-to R less-than-or-equal-to 1) has been investigated by Raman
scattering under VV and VH polarizations. The two systems behave in ne
arly the same way: in the tellurite-rich part, the structure is built
up of [TeO4] trigonal pyramids, a disordered form of the paratellurite
alpha-TeO2. With increasing R between 0.40 (0.35) and 1 (the upper R
value limiting the vitreous domain in each system), an increasing prop
ortion of tri-coordinated tellurium [TeO3] is formed in the glasses. T
he ternary [TeO2-RMO0.5](1-x)[AgI]x glasses have been reported as ioni
c conductors. The structure of the tellurite network is not modified b
y the addition of silver iodide. A band appearing in the low-energy pa
rt of the Raman spectra is assigned to vibrations of [AgI4] species.