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ALT'23 The 30th International Conference on Advanced Laser Technologies
LS-I-10
Study of local structure and thermal properties in Ge-As-Se-S chalcogenide glass fiber optic materials
S.I. Mekhtiyeva1, R.I. Alekberov'-2. S. M. Mammadov1
1 The Ministry of Science and Education of the Republic of Azerbaijan, Institute of Physics G. Javid ave 13, AZ1143
Baku
2Azerbaijan State University of Economics (UNEC), st. Istiqlaliyyat 6, Baku, AZ 1001
e-mail: rahim-14@mail.ru
At present, scientific research is intensively growing in the field of local structure, optical spectroscopy and thermal properties of multicomponent chalcogenide glasses [1]. The main reason of these is related with high optical transparency of multi-component chalcogenide glasses in infrared region of the optical spectrum, as well as, with high optical nonlinearity and photostability, the broad glass-forming region and low energy phonons. Since these substances are obtained by the method of sharp cooling of melt practically remains in non-equilibrium state. The authors of other studies in this field show that the absence of long-range order and thermodynamic non-equilibrium the distinctive sign of glasses is the glass transition temperature Tg [2]. A phase changes does not occur at the temperature corresponding to the glass transition point [2].
The main purpose of this work is to study the relationship between the parameters of local structure and the glass transition temperatures (Tg) in the Ge-As-Se and Ge-As-Se-S chalcogenide glass systems according to theory of topological constraints [3], model the chemically ordered networks [4] and also idea of layered structures [5].
It was determined that partially good agreement exists between the experimental values of glass transition temperatures (Tg) and calculated for Ge -As -Se, Ge -As -Se - S chalcogenide glasses. The value of share of "zero" frequency oscillation modes (f) are equal about to f~0 and average coordination number (Z) change in range of Z=2.5-2.7 for studied glass compositions. The analysis of these results shows that Ge24Asi9S2oSe37, Ge25AsioS25Se4o, Ge26Asi8S3oSe26, Ge33AsnS35Sei5 compositions have high short range order and medium range order can be considered as more stable glasses compositions and prospective materials for fiber lasers. The glass transition temperature (Tg) in the mentioned compositions are higher and varies in the range of 589-689 K.
[[1] Rongping Wang, Kunlun Yan, Zhiyong Yang, Barry Luther-Davies, Structural and physical properties of Ge11.5As24S64.5xSe64.5(1 - x) glasses/Journal of Non-Crystalline Solids 427 (2015) 16-19
[2] A. Popov Handbook of disordered semiconductors: Physics and Applications. Pan Stanford Publishing Pte. Ltd, 2011, 205p
[3] J.C. Phillips, M. F. Thorpe, Constraint Theory, Vector Percolation and Glass Formation// Solid State Communications, -1985, 53(8), -p.699-702, https://doi.org/10.1016/0038-1098(85)90381-3
[4] Tichy, L., Ticha, H., (1995) Covalent bond approach to the glass transition temperature of chalcogenide glasses, J. Noncryst. Solids, 189, 141-146, https://doi.org/10.1016/0022-3093(95)00202-2
[5] K. Tanaka, Structural phase transitions in chalcogenide glasses. Phys. Rev. B 39, 1270-1279 (1989), https://doi.org/10.1103/PhysRevB.39.1270
