The Effect of PbS on Crystallization Behavior of GeS₂‐Ga₂S₃‐Based Chalcogenide Glasses

Abstract

Glass-ceramics of PbS-doped 80GeS 2 Á20Ga 2 S 3 were fabricated by heat treatments of base glasses at T g +30°C for different durations. They exhibited improved mechanical properties such as hardness and resistance to crack propagation, and meanwhile retained their excellent infrared transmission. X-ray diffraction and Raman results indicated that Ga 2 S 3 and GeS 2 crystals were precipitated inside glassy matrix. The crystallization kinetics of base glass was investigated using differential scanning calorimetry under nonisothermal conditions. Compared with the previous work concerning on 80GeS 2 Á20Ga 2 S 3 glass, there exists some different features of crystallization behavior. Such variation is discussed and correlated with the network structure and crystallization kinetics in this glass system.

Controllable Formation of the Crystalline Phases in Ge–Ga–S Chalcogenide Glass‐Ceramics

“…This is in agreement with the well‐known fact that, the chemically stoichiometric glass along the tie‐line of the glass‐forming region is the best for the creation of the glass‐ceramics since the growth of the crystals in the glass is much faster. In contrast, S‐rich or S‐poor glasses are much insert against crystallization via thermal annealing of the glasses at a temperature that is 20°C higher than glass transition temperature . On the other hand, the appearance of the difference crystals in chemically stoichiometric glass is mainly due to the formation of GaS 4 tetrahedron rather than Ga 2 S 3 units in the glass, resulting in sulfur deficiency in Ge 30 Ga 4 S 66 .…”

“…It has been reported that the different crystals can be formed in the surface and interior of the chalcogenide glass‐ceramics in the previous investigations . In order to examine whether the distribution of these crystals is homogeneous, we polished the annealed Ge 27 Ga 4 S 69 chalcogenide glass‐ceramics with different thickness and measured Raman spectra at several different positions as shown in Fig.…”

“…Some methods, such as adding of the alkali halide or PbS quantum dots into chalcogenide glasses, have been developed to control the formation of the nanocrystals in various systems including GeS 2 –Sb 2 S 3 –In 2 S 3, GeS 2 –Ga 2 S 3 , GeS 2 –Sb 2 S 3 –CsCl, GeS 2 –In 2 S 3, and GeS 2 –In 2 S 3 –CsI . However, the relatively high halide content in chalcogenide glasses causes the difficulty in controlling the size of the nanoparticles and leads to poor chemical durability, and sometimes the dopants in the chalcogenide glasses are liable to induce the precipitation of the different crystals simultaneously.…”

Thermal and structural investigations of xLi2O‐(1−x)Bi2O3 (0.25 ≤ x ≤ 0.35) glasses

“…As temperature increases, the growth process is predominantly over the surface and two dimensionally it resembles an attachment of discs. The surface morphology of glasses is also studied, using SEM for GeS 2 ‐Ga 2 S 3 glass ceramics . Different types of crystallinity are obtained due to phase segregation in the glass matrix .…”

Non‐isothermal crystallization kinetics of Al2O3‐YAG amorphous ceramic coating deposited via plasma spraying

“…There is no doubt that the Al 2 O 3 ‐YAG amorphous coating possesses high thermal stability due to its large T c and E c . According to the characteristic temperatures obtained from the as‐received DSC data, the width of the supercooled liquid region Δ T 1 = T c1 − T g was widely accepted to be a representative criterion conducting the nucleation resistance, since the larger value of Δ T 1 corresponds to the greater delay in nucleation (namely, larger heat energy needed for nucleation) . The Δ T 1 of the sample at various heating rates were presented in Table .…”