常圧蒸着法による砒素-硫黄系ガラスの赤外線吸収スペクトル

抄録

The infrared absorption spectra in the range of the wave length from 2 to 25μ have been investigated on arsenic-sulfur glasses, including plastic sulfur, directly prepared in the film form by the evaporation under normal pressure using the evaporation outfit and operating condition shown in the previous paper (Reference 6). Each of the arsenic-sulfur glasses itvestigated here was allowed to cool in atmospheric gas after the condensation in the molten state on the back-surface of aluminum target for rather short time (5-20 min), and was separated from the target by the chemical procedure using dilute hydrochloric acid. The spectra recorded for the above arsenic-sulfur glasses of the composition ranging from As₂S_2.8 to As₂S_15.4 were 9.58±0.05μ(1044±6cm^-1) accompanied by the absorption band at 12.67±0.02μ(789±2cm^-1), 9.55±0.05μ(1047±6cm^-1) appeared without the absorption band at 12.67±0.02μ(789±2cm^-1), 11.95±0.15μ(837±11cm^-1), 12.51±0.05μ(799±4cm^-1), 12.67±0.02μ(789±2cm^-1), 14.84±0.11μ(674±5cm^-1), 15.18±0.05μ(659±3cm^-1) appeared together with the absorption band at 20.69±0.08μ(483±2cm^-1), 19.93±0.07μ(502±2cm^-1), 20.69±0.08μ(483±2cm^-1), 21.09±0.10μ(474±3cm^-1) and 21.36±0.10μ(468±2cm^-1). The spectra for the plastic sulfur were 7.66±0.03μ(1305±6cm^-1)(w), 10.71±0.05μ(934±5cm^-1)(vw), 11.04±0.03μ(906±3cm^-1)(vw), 11.43±0.03μ(875±2cm^-1)(vw), 11.95±0.15μ(837±11cm^-1)(s), 14.06±0.03μ(711±2cm^-1)(w), 14.65±0.05μ(683±3cm^-1)(vw), 15.20±0.05μ(658±3cm^-1)(w) appeared without the absorption band at 20.69±0.08μ(483±2cm^-1), 19.50±0.20μ(513±6cm^-1)(vw) and 21.36±0.10μ(468±2cm^-1)(s), where s, m, w and vw denoted strong, medium, weak and very weak bands, respectively.
No absorption bands due to dissolved gases have appeared for arsenic-sulfur glass films used in the present investigation. Contrary to the observation by Kolomiets and Pavlov (Reference 4) that the absorption band at around 12.5μ was not appeared for “As₂S₃ and As₂S₃⋅As₂Se₃ glasses” but for “As₂S₃⋅2As₂Se₃ and As₂Se₃ glasses” which were all synthesized according to the procedure by Goryunova, Kolomiets and Shilo (Reference 10), the absorption bands at around 12.67μ(789cm^-1)(s) and around 12.51μ(799cm^-1)(m) have been respectively recorded for glasses of the compositions near As₂S_2.8 and As₂S_8.6 which were both prepared from the nearly selenium-free batches by the present evaporation and condensation method.
A satisfactory assignment of the absorption bands recorded for the above glasses of the arsenic-sulfur system has been made mainly from the relationship among glass compositions and band characteristics (the position, broadness, sharpness and intensity of band) and from the comparison of band characteristics among glasses and plastic and crystalline sulfurs, as follows: (1) the absorption band appeared at around 12.51μ(799cm^-1) is attributed to the vibration of As=S bond (the As-S bond with an increased double bond character) in the As₂S₅ glass