AU-197 MOSSBAUER STUDY OF THE GOLD-SILVER DITELLURIDES SYLVANITE, KRENNERITE AND CALAVERITE

Mossbauer spectroscopy of the 77.3 keV gamma-rays of Au-197 was used t o investigate the gold ditellurides sylvanite AuAgTe4, krennerite Au1- xAgTe2 (x almost-equal-to 0.2) and calaverite AuTe2. The gold ditellur ides have been found to exhibit distinctive Mossbauer spectra that can be explained by different amounts of gold on the (4+2) and (2+2+2) ty pe of sites, with the former occupied only by gold, and the latter by gold as well as silver. The Lamb-Mossbauer factors of the (2+2+2) site s were found to be 75% or less of those for the (4+2) sites. The overa ll Lamb-Mossbauer factors for sylvanite, krennerite and calaverite are only about 60% of the Lamb-Mossbauer factor for metallic gold.