Effect of the Melting Conditions on the Uniformity of Chemical Composition in the As₂S₃ Glass

Abstract

As₂S₃ glass rods were prepared by melting the raw materials in evacuated silica glass ampoules which had been placed horizontally in a rocking furnace, and cooled at vertical position.
The effect of the melting temperature ranging 600-900°C on the uniformity of the chemical composition of the glass rod was studied. Maximum difference of the arsenic content at the each fraction of the glass rod, Δ_As, was employed as the evaluation of uniformity of the glass. To keep the ΔAs value less than 0.5wt%, melting time of 24h was required for melting at 600°C, 6h at 700°C, and 1h at 800°C. While only by heating up to 900°C, the Δ_As value went down to 0.3wt% and less.
For the sample with poor uniformity, it was found that the arsenic contents in a lower half of glass rod (63-64wt%) was higher than the average arsenic content (60.9wt%).