Vol. 49, Issue 3, pp. 403-413 (2019)

Abstract

A series of fluorotellurite glasses based on 70TeO₂–5M_xO_y–10P₂O₅–10ZnO–5PbF₂ in mol%, where M_xO_y = (WO₃, Nb₂O₅) doped with 2400 ppm of Er₂O₃ have been prepared by the conventional melt quenching method. The influence of modifiers on thermal and optical properties of glasses has been analyzed. Thermal characteristics of glasses like the glass transition temperature T_g, the temperature for the crystallization onset T_x, the maximum crystallization temperature T_c, and the thermal stability parameter were determined by the DSC method. The ellipsometric data have provided Sellmeier-type dispersion relations of the refractive index of the investigated glasses. The optical parameters are used to calculate the molar refractivity, molar polarizability, oxide ion polarizability, molar cation polarizability, and a number of polarizable atoms per unit volume for every glass composition in order to interpret the refractive index of these glasses.