Modeling of thermal studies on melt quenched Ge₁₈Bi₄Se₇₈ chalcogenide

Abstract

The crystallization characteristics for Ge18Bi4Se78 glass are studied in this work by means of differential thermal analysis (DTA) under non-isothermal conditions. One stage endothermic glass transition and one exothermic crystallization are observed in the DTA curves. The results of topological constraints for Ge18Bi4Se78 glass show that the calculated value of glass transition temperature (Tg) is very close to that of the experimental results. The as-prepared, as well as the annealed samples, are examined using x-ray diffraction (XRD), energy dispersive x-ray spectroscopy (EDX), scan electron microscope (SEM) techniques. Avrami’s exponent (n) found to have an average value of 1.61 ± 0.2 reveals a mixture of one dimensional and surface nucleation stages of growth. Many models are used to estimate the activation energies for glass transition (Eg) and crystallization (Ec). The crystallization process was found to be described by the Sestak- Berggren SB(M, N) model.

Study of Some Physiсal Parameters of Se85-xSnxTe15 Chalсogenide Glasses

“…%) of Sn, Se & Te respectively and CN is the coordination number of each element respectively, CN(Sn) = 4, CN(Se) = 2, CN(Te) = 2 they are calculated by 8-N rule [16]. From equation (1). Figure 1 clearly shows that <r> increases with increasing Sn content, hence, < r > lies in the range from 2.02 to 2.20.…”

“…Chalcogenides have many applications due to their specific properties such as solid-state devices, Solar cells that use amorphous thin layers., optical fiber, memory with phase change, photonics, and chalcogenide glasses (CG) [1]. Selenium-rich alloys are the most distinguished today due to their strong nonlinear optical properties, high refractive index, ideal chemical and physical properties, and high transparency in the infrared regions [2,3].…”

Study of radiation effect and bismuth content on the physical properties of some chalcogenides based on selenium

“…As can be seen in previous work [23], an x-ray energy dispersion analysis [EDAX] was performed for the asprepared Ge 18 Bi 4 Se 78 glass to ensure that the required stoichiometry of our system was achieved. It is found that the atomic percentages of Ge, Bi, and Se were 21.26, 3.79, and 74.95 at% for Ge, Bi, and Se, respectively.…”