Thermal and mechanical properties of some thallium-containing chalcogenides

The results of differential thermal analysis (DTA) and differential scanning calorimetric (DSC) measurement as well as of measurements of the microhardness (H-k) on chalcogenide thin films and bulk samples from the systems As-S-Tl and Ge-S-Tl in wide range of concentrations are reported. The dependence of H-k on composition shows an increase in the hardness with the rise of the As and Ge content for the first two systems and a very large decrease in it when the Tl content increases. It is also found that the glass-transition temperature of bulk samples as well as thin films decreases when Tl content increases. No influence of the vacuum deposition conditions of thin films on the microhardness has been observed. It was shown that a correlation exists between the mechanical and thermal properties of the studied chalcogenide systems.