Theoretical prediction of physical parameters of GexSb20−x Te80 (x = 11, 13, 15, 17, 19) bulk glassy alloys

2014 ◽  
Vol 32 (4) ◽  
pp. 661-668 ◽  
Author(s):  
Ishu Sharma ◽  
Monisha Maheshwari
Keyword(s):  
Coordination Number ◽  
Bond Energy ◽  
Cohesive Energy ◽  
Lone Pair ◽  
Average Coordination Number ◽  
Physical Parameters ◽  
Calculated Density ◽  
Glassy Alloys ◽  
Mean Bond Energy ◽  
Lone Pair Electrons

AbstractPhysical properties of GexSb20−x Te80 (x = 11, 13, 15, 17, 19) bulk glassy alloys are examined theoretically. Lone pair electrons are calculated using an average coordination number (〈r〉) and the number of valence electrons, and are found to decrease with an addition of Ge. Mean bond energy (〈E〉) is proportional to glass transition temperature (Tg) and shows maxima near the chemical threshold. Cohesive energy of the system is calculated using chemical bond approach. A linear relation is found between cohesive energy, band gap (calculated theoretically and confirmed experimentally) and average heat of atomization. All these parameters are increasing with an increase in Ge content. A relation between average single bond energy and photon energy is discussed. Compactness of the structure is measured from the calculated density of the glass. An attempt is made to discuss the results in terms of structure of the glass or equivalently with average coordination number.

Optical gaps from ‘mean’ bond energy in Ge1−x S x and Ge k Sb m S n non-crystalline solids

1982 ◽  
Vol 46 (4) ◽  
pp. 365-376 ◽  
Author(s):  
L. Tichý ◽  
A. Tříska ◽  
Č. Barta ◽  
H. Tichá ◽  
M. Frumar
Keyword(s):  
Bond Energy ◽  
Crystalline Solids ◽  
Mean Bond Energy

A Study of the Physical Properties of Te15(Se100-xBix)85 Glassy Alloys

2010 ◽  
Vol 305-306 ◽  
pp. 61-69 ◽  
Author(s):  
Kameshwar Kumar ◽  
Nagesh Thakur ◽  
S.C. Katyal ◽  
Pankaj Sharma
Keyword(s):  
Glass Transition ◽  
Transition Temperature ◽  
Glass Transition Temperature ◽  
Coordination Number ◽  
Bond Energy ◽  
Cohesive Energy ◽  
Energy Gap ◽  
Average Coordination Number ◽  
Glassy Alloys ◽  
Mean Bond Energy

In the present communication, a study was made of the compositional variation of physical properties: average coordination number (<r>), average number of constraints (Ncon), number of lone-pair electrons (L), mean bond energy (<E>), cohesive energy (CE), average heat of atomization (Hs), glass transition temperature (Tg), density (ρ) and theoretical energy gap (Eg) for Te15(Se100-xBix)85 (x = 0, 1, 2, 3, 4, 5at%) glassy alloys. The mean bond energy and the cohesive energy have been calculated using the chemical bond approach (CBA). The glass transition temperature was calculated using the Tichy-Ticha approach, and has been found to increase with Bi content. The mean bond energy is found to be proportional to the glass transition temperature and the average coordination number. It has been found that the average coordination number, average number of constraints, mean bond energy and density increase, whereas the cohesive energy, average heat of atomization and theoretical energy gap decrease with increasing Bi content in Se-Te alloys.

scholarly journals The effect of adding CsCl content on physicochemical properties of (GeS2–Sb2S3)100-x(CsCl)x (0 ≤ x ≤ 40 mol%) chalcohalide glasses

2021 ◽  
Author(s):  
Imed Boukhris ◽  
Imen Kebaili
Keyword(s):  
Glass Transition ◽  
Transition Temperature ◽  
Bond Energy ◽  
Unit Volume ◽  
Chemical Properties ◽  
Lone Pair ◽  
Physico Chemical ◽  
Chalcohalide Glasses ◽  
Mean Bond Energy ◽  
Lone Pair Electrons

Abstract The physico-chemical properties of (GeS2–Sb2S3)100-x(CsCl)x (0 ≤ x ≤ 40 mol%) chalcohalide glasses were theoretically studied. The band gap (Eg) of the studied glass system was estimated and was found to increase by adding the CsCl content. Furthermore, the positions of the valence band and conduction band edges was determined. The results reveal that the molar volume (Vm) of the studied samples increased while the density (ρ) and the number of atoms per unit volume (N) decreased with increasing the CsCl content. The overall coordination number (CN), constraints number (Ns) and overall mean bond energy (<E>) were computed using the chemical bond approach and were found to decrease. In contrast, the number of lone-pair electrons (LP) and cohesive energy (CE) increased. Finally, the glass-transition temperature (Tg) was also estimated based on the overall mean bond energy, and was found to decrease with increasing the CsCl content.

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