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.

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.

scholarly journals Effect of Sn Incorporation on Physical Parameters of Sb-Se Glassy System

2020 ◽  
Vol 12 (4) ◽  
pp. 545-554
Author(s):  
R. Khajuria ◽  
A. Sharma ◽  
P. Sharma
Keyword(s):  
Glass Transition ◽  
Transition Temperature ◽  
Glass Transition Temperature ◽  
Band Gap ◽  
Bond Energy ◽  
Chalcogenide Glasses ◽  
Lone Pair ◽  
Physical Parameters ◽  
Glassy System ◽  
Almost All

The rationale of this study is to investigate band gap tailoring of Sb-Se-Sn chalcogenide glasses. This study has been accompanied by the assessment of various theoretical parameters such as average co-ordination number, Lone-pair of electrons, number of constraints, average heat of atomization, mean bond energy and glass transition temperature. It has been observed that almost all these physical parameters have been enhanced with the increase in tin (Sn) content except Lone-pair of electrons. The number of lone-pair electrons has been decreased with the increase in Sn content. The glass transition temperature has been observed to increase due to the addition of Sn atom in the Se-Sb glassy system. The band gap is decreasing with increase in Sn content due to overall decrease in the average single bond energy of the Sb-Se-Sn glassy system.  

Fractional Exponent of the Modified Stokes-Einstein Relation in the Metallic Glass-Forming Melt Pd43Cu27Ni10P20

2010 ◽  
Vol 146-147 ◽  
pp. 1463-1468
Author(s):  
Masahiro Ikeda ◽  
Masaru Aniya
Keyword(s):  
Diffusion Coefficient ◽  
Glass Transition ◽  
Transition Temperature ◽  
Glass Transition Temperature ◽  
Metallic Glass ◽  
Bond Strength ◽  
Coordination Number ◽  
Einstein Relation ◽  
Glass Forming ◽  
Highly Correlated

The diffusion coefficient in the metallic glass-forming systems such as Pd-Cu-Ni-P exhibits a marked deviation from the Stokes-Einstein (SE) relation in the proximity of the glass transition temperature. Such a deviation is characterized by the fractional exponent p of the modified SE expression. For the material Pd43Cu27Ni10P20, it has been reported that it takes the value p = 0.75. In this work, it is shown that the value of p is highly correlated with the ratio ED / ENB, where ED and ENB are the activation energies for diffusion coefficient D and cooperativity NB defined by the Bond Strength-Coordination Number Fluctuation (BSCNF) model. The present paper reports that for the metallic glass-forming melt Pd43Cu27Ni10P20, the fractional exponent p can be calculated accurately within the framework of the BSCNF model.

Properties and Structure of BaO-ZnO-B2O3 Glasses

2008 ◽  
Vol 368-372 ◽  
pp. 1433-1435 ◽  
Author(s):  
Young Seok Kim ◽  
Young Joon Jung ◽  
Kyu Ho Lee ◽  
Tae Ho Kim ◽  
Bong Ki Ryu
Keyword(s):  
Glass Transition ◽  
Transition Temperature ◽  
Glass Transition Temperature ◽  
Coordination Number ◽  
Softening Temperature ◽  
Chemical Durability ◽  
The Other ◽  
Glass Forming ◽  
Other Hand ◽  
Glass Properties

The effect of coordination number on glass properties was investigated by measuring the glass forming region, glass transition temperature, dilatometric softening temperature, density and chemical durability of the glasses. The coordination number of B and Zn in the system 20BaO-xZnO-(80-x) B2O3 glasses (x=0~40mol%) was measured by IR, respectively. No change in the coordination number (CN) of B was revealed, and the coordination of Zn was 4 at ZnO 10mol%, which increased the properties of glasses. On the other hand, the coordination number (CN) of B and Zn changed from CN4 to CN3, CN4 to CN6 over ZnO 20 and 10mol% respectively, which decreased the properties of glasses.

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.

New Au-based bulk glassy alloys with ultralow glass transition temperature

2009 ◽  
Vol 61 (7) ◽  
pp. 744-747 ◽  
Author(s):  
W. Zhang ◽  
H. Guo ◽  
M.W. Chen ◽  
Y. Saotome ◽  
C.L. Qin ◽  
...  
Keyword(s):  
Glass Transition ◽  
Transition Temperature ◽  
Glass Transition Temperature ◽  
Glassy Alloys
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