CALORIMETRIC STUDY OF PHASE TRANSITIONS OF Ag₈SiS₆(Se₆) COMPOUNDS
Chemical Problems, vol.24, no.1, pp.104-110, 2026 (Scopus)
- Publication Type: Article / Article
- Volume: 24 Issue: 1
- Publication Date: 2026
- Doi Number: 10.65382/2221-8688-2026-1-104-110
- Journal Name: Chemical Problems
- Journal Indexes: Scopus, Academic Search Ultimate (EBSCO)
- Page Numbers: pp.104-110
- Keywords: argyrodite, differential scanning calorimetry, enthalpy and entropy of phase transformation, phase transition, thermodynamic functions
- Open Archive Collection: Digital Heritage Collection
- Azerbaijan State University of Economics (UNEC) Affiliated: Yes
Abstract
Polymorphic transitions in the Ag8SiS6 and Ag₈SiSe₆ compounds were studied by differential scanning calorimetry (DSC). Two samples of each compound with different sample weights in the range from 20 to 50 mg were selected for the studies, for which three DSC heating curves were recorded. Based on the DSC curves, the temperatures and enthalpies of phase transitions of the studied compounds from the low-temperature rhombic modification to the high-temperature cubic modification were determined. The data obtained on all DSC heating curves for each sample did not exceed 2. The entropies of these transitions (Δ Sp.t.) were calculated from the values of heats and temperatures. It was shown that the values of Δ Sp.t. both compounds have anomalously high values, which can be explained by the complete delocalization of silver ions in the cation sublattice during the transition from low-temperature modifications to high-temperature cubic ion-conducting phases.