New heavy metal oxide glasses: investigations within the TeO2–Nb2O5–Bi2O3 system

The TeO2–Nb2O5–Bi2O3 system was investigated by differential scanning calorimetry and temperature programmed X-ray diffraction. A large glass-forming domain was evidenced and the complex structural evolution with temperature of these glasses was followed. The glass transition and crystallisation temperatures and the nature of crystalline phases formed were determined. Moreover, this study confirmed the existence of the metastable γ-TeO2 polymorph and of a new crystalline compound, BiNbTe2O8. [Copyright &y& Elsevier]