The doping behavior of the group III additive Indium in GexSe1-x glasses is examined in temperature modulated DSC (MDSC) measurements. The results show that variation in Tg, (dTg/dy)obs, in GexInySe1-x-y glasses, in the floppy (x = 0.10), intermediate (x = 0.22) and stressed rigid (x > 0.26) phases reveal slopes that can be quantatively understood in term of a model in which In segregates into nanocrystalline In2Se3 clusters. A parallel behavior is suggested for Ga in stressed rigid (x > 0.26) base glasses.
Molecular structure of Ge x S 1-x glasses in the 0.30 < x < 0.34 range is examined by Raman scattering, 119Sn Mössbauer spectroscopy, and MDSC. The results show that the stoichiometric glass, x = 1/3 (Tg = 508°C is partially polymerized into 3 phases; a majority phase consist of Ge(S1/2)4 tetrahedra (A); a Ge-rich minority phase consisting of ethanelike Ge2(S1/2)6 units (B), and a minority GeS phase consisting of distorted rocksalt Ge(S1/6)6 units (C) in approximately 93.4 : 3.6 : 3.0 ratio as deduced from Raman scattering.
Raman Scattering and MDSC investigations of the molecular structure of (GeS2)1-x(Ga2S3)x glasses shows the existence of a rather striking anomaly when x = 17%. In the 0 < x < 17% range, additive (Ga 2 S 3 ) enters the base glass as Ga(S 1/2 ) 4 units forming part of the base glass network, and results in a Ge-rich Ge 2 S 3 nanophase to segregate from the backbone. At x > 17%, the additive (Ga2S3) now nucleates a Ga-rich, GaS like phase, releasing S that permits Ge2S3 nanophase to alloy back in the base glass network.