Influence of Hydroxyl Group on IR Transparency of Tellurite-Based Glasses

A study of the glass properties with two opposite levels of hydroxyl content is presented for two different tellurite glass families with molar composition 70TeO2-10Bi2O3-20ZnO and 80TeO2-20Nb2O5. We show that melting tellurite-based glasses in a dried-oxidant atmosphere (relative humidity <1%) reduces drastically the OH impurities. The effect of reducing the OH content on the glass properties such as characteristic temperatures, crystallization stability (ΔT), density, and microhardness is investigated.