Bvr. Chowdari et al., Synthesis and characterisation of CuI center dot Cu2O center dot TeO2 center dot MO3 (M = Mo or W) glass systems, SOL ST ION, 136, 2000, pp. 1101-1109
Glasses based on the ternary oxide system Cu2O-TeO2-MO3 (M = Mo or W) doped
with CuI were synthesized according to the formula zCuI . (1 - z){xCu(2)O
. (1 - x)[yTeO(2) . (1 - y)MO3]} (M = Mo, z = 0.3, 0.4 and 0.5 and M = W, z
= 0.3 and 0.4, respectively) in vacuum or argon atmosphere using the twin-
roller quenching technique. The glasses exhibit phase separation and in mos
t compositions a-CuI crystallites are stabilized at room temperature as con
firmed by XRD and HRTEM. The highest ionic conductivity at 298 K is similar
to 3 X 10(-4) S cm(-1). The Arrhenius plots show a break in the temperatur
e range 294+/-5 K with sigma increasing from 10(-5) S cm(-1) to 10(-4) S cm
(-1). The conductivity below 294 K and above 295 K is due to the ionic cond
uction by Cu+ in the oxide glass matrix and the halide phase, respectively.
DSC studies do not show any phase transition in the region 294+/-5 K. FTIR
study indicates that the IR bands of glasses are not affected by doping of
CuI. XPS studies show that the fractional area of Cu 2p peaks [Cu+/(Cu+ Cu2+)] are in the range 0.35-0.61 and 0.44-0.72 for systems with M = Mo and
W, respectively. The average fraction of non-bridging oxygen (NBO) is high
er than that in the corresponding oxide glasses without the CuI dopant. (C)
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