Differential thermal analysis of Ag-Ge-Se, Ge-Se charge materials in the process of their heating and Ag8GeSe6, GeSe2 compound synthesis

This is the first comprehensive study of the processes of phase transformations (PT) and chemical reactions (CR) that accompany Ge-Se and Ag-Ge-Se charge material heating in stoichiometric proportions corresponding to GeSe2 compounds, Ag8GeSe6 argyrodite and elementary selenium. The investigation was carried out by means of the differential thermal analysis (DTA) method. The PT in selenium and the main types of PT and CR of the formation of GeSe2, Ag8GeSe6 compounds have been identified. The characteristic heats and temperature ranges of reaction processes have been determined. Ag8GeSe6 and GeSe2 compounds formation has been experimentally demonstrated due to the DTA and X-ray analysis. (C) 2011 Elsevier B.V. All rights reserved.