Structural Analysis of Ge-Ga-Se/S-CsCl Glasses and Glass-Ceramics for Application in Chalcogenide and Chalcohalide Photonics

Abstract

The current state-of-the-art of the modern photonics indicates on significant importance of glassy-like multifunctional media with improved exploitation proper-ties. For example, chalcogenide and chalcohalide glasses were considered attractive materials for infrared (IR) optics because of their excellent IR transmittance, low-cost raw material and relatively simple molding process (Yang Z et al. Mater Res Bull 43:3596–3600, 2008). The nearest atomic arrangement in a glass and glass-ceramics can be adequately studied with numerous experimental measuring techniques. However, the row of probes available to study atomic-deficient distribution is rather limited, especially at sub-nanometer scale. One of the best (if not unique) techniques capable to probe such finest free volumes is the positron annihilation lifetime (PAL) spectroscopy, the method grounded on physical phenomena of positron-electron interaction in a matter (Klym et al. physica status solidi (c) 4:715–718, 2007). In the present paper, we imply, for the first time, the PAL method to reveal changes in free-volume structure of 80GeSe2-20Ga2Se3 chalcogenide glasses (ChG) subjected to thermally-activated crystallization and (80GeS2-20Ga2S3)100−x (CsCl) x , 0 < x < 15, chalcohalide glass-ceramic composites.