Synthesis and physical properties of glasses in the Sb2O3–PbCl2–MoO3 system

Lead chloroantimonite glasses form stable binary glasses that may accommodate numerous oxides or halides as a third component. Molybdenum trioxide is a glass progenitor leading to molybdate glasses. Ternary glasses have been synthesized and studied in the Sb2O3–PbCl2–MoO3 system. Compositional limits of glass formation are reported and two series of glass samples have been prepared corresponding to the general formulas: (90 − x)Sb2O3–xPbCl2–10MoO3 and (90 − x)Sb2O3–xMoO3–10PbCl2. Glass transition temperature is close to 290 °C at high Sb2O3 content and decreases as antimony oxide is substituted by MoO3 or PbCl2. Position, width and intensity of crystallization peak suggest that devitrification rate is small in some composition ranges. The evolution of density, thermal expansion, refractive index and microhardness has been studied as a function of composition parameter x. Deviations from linearity are observed. They suggest structural changes in the case of the MoO3/Sb2O3 substitution while it appears that molar volume increases linearly versus lead content in the other series of glasses. Refractive index is close to 2.04. Optical transmission ranges from 550 nm in the visible spectrum to 5.5 μm in the infrared. It is limited by extrinsic absorption bands arising from hydroxyls and silicon impurities. Young's, bulk and shear moduli have been measured for the two series of samples.

► Vitreous area is reported in the Sb2O3–PbCl2–MoO3 ternary system. ► Glass transition temperature increases with antimony oxide content. ► Substituting Sb2O3 by PbCl2 results in larger refractive index, density and thermal expansion. ► The change in microhardness, thermal expansion and elastic modulus is nonmonotonous as MoO3 replaces Sb2O3.