Evolution of glass properties during a substitution of S by Se in Ge28Sb12S60−xSex glass network

Abstract

In this paper, a detailed study to examine the influence of chalcogen S/Se mole % in the Ge 28 Sb 12 S 60 −x Se x glass system, with x = 0, 15, 30, 45 and 60, is presented that provides insight into the effect of chalcogen content on the glass network and properties. Specifically, we report results of a systematic study to evaluate the relationship between compositional variation, glass properties and dominant bonding configurations. These materials are important to applications in optics manufacturing where correlation of physical and optical properties is required to predict fabrication behavior and ultimate material performance. It has been found that the dominant bonds in the glass system change upon reaching a specific molar ratio (percentage, %) of chalcogen substitution, between 30 b x b 45 mol%, changing from Ge-Se to Sb-Se bonds as the dominant bond type. This singularity has been observed using micro-Raman spectroscopy and X-ray photoelectron spectroscopy. This effect of the dominant bond configurational change was also shown to impart changes in important physical properties including micro-hardness, thermal properties, and the glass' viscometric behavior. Results indicate that the observed dominant bond change was responsible for a constant value in the evolution of both the micro-hardness and calorimetric glass transition temperature. The viscosity was also affected by the change in dominant bond type, breaking the monotony of the viscosity evolution during the S substitution, due to the total strength of the vitreous system which does not linearly increase.

Influence of Proton Ion Irradiation on the Linear–Nonlinear Optoelectronic Properties of Sb40Se20S40 Thin Films at Different Fluences for Photonic Devices

“…The primary intense peaks in the irradiated film at 148 cm –1 (A 2 2u mode) and 252 cm –1 are linked to the Sb–Sb bond in the (Se 2 ) Sb–Sb (Se 2 ) structural unit. Similarly, the 198 cm –1 peak denotes the heteropolar Se–Sb bond stretching mode in (SbSe 3/2 ) pyramids connected through a bridging Se. , Among all ion-irradiated films, we observe that the weakly ion-irradiated film, i.e., 5 × 10 15 ions/cm 2 , shows a higher intensity, which shows more structural changes in the film and decreased with a further increase in ion dose. Proton irradiation results in the breaking of weaker homopolar bonds such as Se–Se bonds and creates comparatively stronger (SbSe 3/2 ) pyramidal units with a slight shift in wavenumber, which results in a decrease in disorder in the system and enhancement of the optical energy gap.…”

Structural and spectroscopic ellipsometry studies on vacuum-evaporated Sn2m−4Sb4S2m+2 (m = 2.5, 3 and 4) thin films deposited on glass and Si substrates

“…According to the molecular model [39], each Sb atom in the Sn-Sb-S ternary compound is covalently The band situated at 163 cm -1 can be assigned to stretching modes of Sn-tetrahedral units [40,41]. Other authors reported that this peak (163 cm -1 ) corresponds to a vibration related to the presence of Sb-Sb linkages [42]. Hence, the vibration band around 163 cm −1 in Sn 2m-4 Sb 4 S 2m+2 (m = 2.5, 3 and 4) could be the combined effect of the stretching modes of Sntetrahedra and Sb-Sb linkages.…”

Enhancement of third-order nonlinearity of thermally evaporated GeSbSe waveguides through annealing

“…4(b). The glass transition temperature defined by the viscosity occurs at approximately 285°C (10 12 Poise) while the Littleton point, the point at which a glass deforms under its own weight, occurs at approximately 340°C (10 7.6 Poise) [39,50]. The waveguide geometry remains intact at temperatures below 285°C and deforms completely as the temperature approaches 340°C.…”