مطالعه تغییرات شمیایی و ساختمانی سولفیدهای نقره و مس توسط SRS (مطالعه‌ای از کاربردهای سینکروترون بر مبنای XAS در کانی‌شناسی- بلورشناسی و ژئوشیمی)

The ABS2 sulphides (A=Cu, or Ag), B=As, Sb, Bi) are a naturally occurring group of minerals, typically found in polymetallic vein deposits. Behind chemically simple, the minerals have a complex structure and undergo several temperature/composition phase transitions. In this study, synchrotron radiation is used to collect Ag, As, Bi, Cu, Cd, Hg and Sb K-edge EXAFS data from a series of synthetic sulphosalts. EXAFS are used to characterize and determine the local structure behavior. Analysis of the spectra has provided direct evidence about the coordination environment, the structural and electronic environments of major and minor cations within the substituted phases. In this study, M (metal or semimetal)-S bond distances of emplectite, chalcosibite, miargyrite and smithite minerals were determined by EXAFS and XANES methods.