Improved chemical durability and thermal stability of zinc boro-tellurite glass

Abstract

Glasses with compositions (60-x) TeO2 +30B2O3+10ZnO+xEr2O3 (where x=0, 0.5, 1, 1.5 and 2.0 mol%) were prepared by melt quenching method. The chemical durability of these glasses measured from their weight before and after weathering by water and ammonium hydroxide showed significant improvement with the increase of rare earth contents. X-ray diffraction (XRD) measurements confirmed the amorphous nature of the as-prepared glasses. The glass transition temperature, crystallization temperature and melting point of the samples were determined using differential thermal analyzer. The elemental analyses are performed using EDX and the surface morphology by SEM technique. The enhancement in the thermal stability with the addition of the erbium contents indicates the increased glass forming tendency against crystallization. The fragility factor and Hruby parameter are increased from 1.098-2.897 and 145-160 respectively as the erbium concentration increased from 0-2.0 mol%. The influence of erbium oxide on the surface morphology, chemical durability and water resistivity of the zinc-boro-tellurite glasses are examined. These attractive features on improved chemical durability and thermal stability suggests that these glasses can be nominated as suitable host for the development of solid state lasers with good performance in different temperature and environments.