Antimony-modified soda-lime-silica glass: Towards low-cost radiation-resistant materials

Abstract

The development of inexpensive radiation-resistant glass is important for potential applications in displays, optics, and nuclear or space environments. This study considers the γ-ray and X-ray resistance of glasses relevant to low-cost float glass (i.e., SiO2–Na2O–CaO–MgO), modified with various concentrations (0 – 10 mol%) of Sb2O3. Various doses (0, 0.2, 2.0, and 5.0 MGy) of γ-rays from the decay of 60Co nuclei, and X-rays generated by an X-ray fluorescence (XRF) spectrometer, have been applied to this series of Sb2O3-modified float-type glasses to study their resistance to radiation-induced damage. Irradiation leads to the formation of various defect centres (HC2, HC1, TE, E', and E− types). These radiation-induced defects cause photo-darkening of the glass, which reduces its visible-wavelength optical transparency. The addition of Sb2O3 to these glasses led to reductions in the formation of radiation-induced defect-centres, combined with forbidden bandgap narrowing which led to non-linear changes in visible-wavelength absorption as a function of Sb2O3 content such that the most transparent irradiated glasses were advantageously obtained at low (0.5 mol%) Sb2O3 content. The mechanisms of defect-formation involve the creation of Sb4+-ions which assists in mitigating the effects of irradiation on the visible-wavelength transparency of the glass. The 0.5 mol% of Sb2O3-modified float glass provided a maximized concentration of Sb4+-ions upon γ-ray irradiation. Combined with the smallest changes in the UV band gap narrowing, it enabled this glass to retain the highest visible-wavelength transparency at all doses of ionizing radiation studied (0.2, 2 and 5 MGy). This work confirms the substantially enhanced radiation resistance of Sb2O3-modified float-type glasses compared to standard float glass, which could potentially be further developed towards commercialization, for example as a low-cost solution for radiation resistant applications.