Sulfur as the source of hydrogen impurity and heterogeneous inclusions in the Ge-Ga-S glasses

Abstract The IR spectrometric method for determination of hydrogen impurities in the form of SH-groups in liquid sulfur is developed. The temperature dependence of the content of SH-groups in sulfur samples in the range of 300–550 °C is studied. The technique for deep sulfur purification including vacuum distillation, passing sulfur vapor through catalysts based on silicon, aluminum and cerium oxides, and filtering the vapor using high-purity silica-glass micro-filters is developed. The sulfur containing 40±4 ppb(at) SH-group is prepared. By using the high-purity sulfur samples of various origins, Ga5Ge36S59 glasses are synthesized. Sulfur is shown to be the essential source of hydrogen impurity and heterogeneous inclusions in the glasses. The minimum hydrogen content in the form of SH-groups in the Ga5Ge36S59 glass sample, prepared from the sulfur purified using the developed technique, is 0.10±0.02 ppm(at). The content of heterogeneous micron-sized inclusions in this glass sample is not exceed 10 pieces/cm3.