Impact of impurities on the thermal properties of a Li2S–SiS2–LiPO3 glass

The preparation of 0.58 Li₂S + 0.315 SiS₂ + 0.105 LiPO₃ glass, and the impacts of polysulfide and P^1P defect structure impurities on the glass transition temperature (T_g), crystallization temperature (T_c), working range (ΔT≡ T_c - T_g), fragility index, and the Raman spectra were evaluated using statistical analysis. In this study, 33 samples of this glass composition were synthesized through melt-quenching. Thermal analysis was conducted to determine the glass transition temperature, crystallization temperature, working range, and fragility index through differential scanning calorimetry. The quantity of the impurities described above was determined through Raman spectroscopy peak analysis. Elemental sulfur was doped into a glass to quantify the wt% sulfur content in the glasses. Linear regression analysis was conducted to determine the impact of polysulfide impurities and P^1P defect impurities on the thermal properties. Polysulfide impurities were found to decrease the T_g at rate of nearly 12°C per 1 wt% increase in sulfur concentration. The sulfur concentration does not have a statistically significant impact on the other properties (α = 0.05). The P^1P defect structure appears to decrease the resistance to crystallization of the glass by measurably decreasing the working range of the glasses, but further study is necessary to fully quantify and determine this.