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 70TeO(2)-10Bi(2)O(3)-20ZnO and 80TeO(2)-20Nb(2)O(5). 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 (DT), density, and microhardness is investigated.