Vibrational and structural properties of unmodified and radiation-modified chalcogenide glasses for advanced optical applications

Vibrational and structural properties of GexSb40 xS60 (x = 25, 27, 35) chalcogeide glasses are studied in unmodified and γ-radiation-modified states by using infrared spectroscopy, high-energy synchrotron x-ray diffraction and extended x-ray absorption fine structure spectroscopy. An agreement between radiation-induced structural changes and vibrational properties measured is established. It is suggested that the atomic pairs with wrong coordination created in the framework of coordination topological defect formation concept play a key role in the formation of radiation-modified state of the investigated glasses. Advantages and disadvantages of post-technological radiation-modification of chalcogenide glasses are considered within configuration coordinate model for description of unmodified and radiationmodified states.