THERMAL STABILITY OF SOME GLASSY COMPOSITIONS OF THE Ge-As-Te TERNARY

Tellerium-based chalcogenide glasses have been studied extensively in the recent past not only because of their technological applications, but also due to their interesting physical properties. Tellerium is a good element for far infrared transmission but is a poor glass former. Glass forming domains are very narrow in binary Ge-Te or As-Te system. Better glass forming ability and thermal stability are observed in presence of arsenic and germanium atoms. These glasses possess a wide optical window that is maximal for the Ge10As20Te70 glass (20 mu m). It made it possible to show that the substitution of germanium by selenium and antimony reduces the physical properties (rho, Eg, Tg, Tc-1, Tc-2, Tc-1-Tg et T-m). Indeed germanium supports the formation of glasses, contrary to metal antimony.