Crystallization behavior of 80GeS2 ⋅ 20Ga2S3 chalcogenide glass

Abstract

International audienceGlass-ceramics were fabricated from the 80GeS2⋅20Ga2S3 chalcogenide glass using an appropriate heat-treatment at a fairly low temperature (T g+30°C) for different durations. Compared with the base glass, they present much-improved thermal shock resistance and fracture toughness, and meanwhile remain an excellent mid-IR transmission in 2-10-μm spectral region. XRD results indicate that the enhanced mechanical properties are mainly due to the appearance of Ga2S3 crystals, and only a very small amount of GeS2 was precipitated on the surface. Bulk and powder samples heat-treated at 458°C for different durations were used to study the evolution of the two crystallization peaks using DSC measurement. It is found that the precipitation of Ga2S3 phase is responsible for the exotherm of first crystallization peak and that of GeS2 phase for the second one. The crystallization mechanism was also examined using the nonisothermal method, and the considerably low activation energy (E c) and high crystallization rate constant (K) for the first crystallization peak illustrate a much easier precipitation of Ga2S3 phase than that of GeS2 phase, which is in good accordance with the ceramization process

Evidence of network demixing in GeS2–Ga2S3 chalcogenide glasses: A phase transformation study

“…Details of the glass preparation can be found elsewhere [23]. The compositions of the prepared glass was analyzed by electron probing micro-analysis (EPMA, JXA-8800R), revealing that the difference between theoretical and real compositions was within a reasonable range (71 at%).…”

“…Unfortunately, this structural information was restricted within the SRO length scale, and no specific structural order beyond the next nearest-neighbor units was clarified. In addition, although many works deal with the crystallization of chalcogenide or chalcohalide glasses containing Ge and Ga [23][24][25], the crystallization mechanism was still not explained yet.…”

Upconversion luminescence in Er3+ doped Ga10Ge25S65 glass and glass-ceramic excited in the near-infrared

“…Notice that the GGS-GC absorption edge is red-shifted with respect to the GGS-GLASS; it is an indication that the crystallization of the inner crystalline phase has been completed after 15 h of heat-treatment. 11 The optical gap energy, E g , for both samples was determined from Fig. 1 one obtained with excitation at 1480 nm.…”

Enhanced mid-IR luminescence of Tm3+ ions in Ga2S3 nanocrystals embedded chalcohalide glass ceramics

“…After heat treatment, the main band at 29°which is indexed to the Ga 2 S 3 phase (JCPDF card nos. 45-891) [15] becomes sharp and grows with increasing durations, indicating the increase of grain size and amount. For the 16 hours heat-treated sample, multiple peaks corresponding to Ga 2 S 3 and GeS 2 (JCPDF cards of nos.…”

“…For the 16 hours heat-treated sample, multiple peaks corresponding to Ga 2 S 3 and GeS 2 (JCPDF cards of nos. 26-693) [15] phases appear and the latter is responsible for the losing of IR transparence.…”