Study of the pseudo-ternary Ag2Si,As2S3i,HgI2 vitreous system

Chalcogenide alloys in the Ag2Si,As2S3i,HgI2 pseudo-ternary system were synthesized and their vitreous nature was verified by X-ray diffraction. The glass transition and crystallization temperatures (Tg and Tc), the density (d), and the total electrical conductivity (I) were measured for all samples of three series, A, B, and C corresponding to (Ag2S)50ax/2(As2S3)50ax/2(HgI2)x, (Ag2S)y(As2S3)80ay(HgI2)20 and (Ag2S)z(As2S3)50(HgI2)50az, respectively. The maximum of Tg was approximately 160 degree C for glasses with low HgI2 content whereas the maximum of density (5.75 g cma3) was obtained for the sample in the B-series with the highest Ag2S concentration (z=60 mol%). This composition also possesses the highest conductivity at 298 K (I298 Ka10a3 S cm-1). Unexpectedly the conductivity of the A-series samples was observed to decrease as a function of the Ag2S content. The far-infrared transmission in the 100a600 cm-1 window range (3.3a18.2 THz, 100a16.6 mu m) was also given for a few glass compositions highlighting the strong influence of the HgI2 content.