Akademik Məlumat İdarəetmə Sistemi
I INTERNATIONAL CONFERENCE ON CURRENT PROBLEMS IN ENGINEERING AND APPLIED SCIENCES (ICCPEAS 2025), Baku, Azerbaijan, 27 - 29 November 2025, pp.52, (Summary Text)
( ) ( ) 2 1− − 2 solid solutions are materials of both theoretical and practical importance. Due to their complex structure, they are widely used as key components in semiconductor laser devices and in the production of sensitive semiconductor converters. The study of the thermodynamic properties of such compounds requires not only the development of theoretical models but also the verification of empirical formulas describing the relationships between thermal parameters. One of the most significant thermodynamic indicators is the Grüneisen parameter, which reflects the degree of anharmonicity in atomic vibrations within the crystal lattice. Knowing its value allows for the prediction of temperature-dependent characteristics such as the coefficient of thermal expansion, specific heat capacity, and isothermal compressibility [1,2]. Based on existing thermodynamic relationships, a direct correlation can be established between the Grüneisen parameter and the atomic packing density in the crystal lattice [3,4]. In this study, using experimental data on the thermal parameters of ( ) ( ) ( 0,1; 0,2) TlGaSe2 1−x − TlInS2 x x = solid solutions, the values of the Grüneisen parameter and atomic packing density were calculated. The main objective of the research was to identify the dependence between these quantities. According to the applied methodology, the investigated solid solutions were synthesized, and their single crystals were obtained [5]. X-ray diffraction analysis was performed to determine the type and quality of the crystal structure. It was found that both compositions crystallize in a monoclinic system, with the following lattice parameters: for 2 0,9 2 0,1 (TlGaSe ) (TlInS ) composition: 10,765 ; 10,558 ; 15,635 ; 100,6 0 0 0 a = A b = A c = A = for 2 0,8 2 0,2 (TlGaSe ) (TlInS ) composition: 10,531 ; 10,598 ; 15,632 ; 100,6 0 0 0 a = A b = A c = A = Samples of appropriate dimensions were prepared from the obtained single crystals, and measurements of the thermal expansion coefficient and isothermal compressibility were carried out. The results showed that there is indeed a direct relationship between the Grüneisen parameter and atomic packing density, confirming theoretical models and expanding the understanding of anharmonic vibrations in crystal structures. Thus, it can be concluded that by changing the mass ratio of the TlInS2 components in the composition of the ( ) ( ) TlGaSe2 1−x TlInS2 solid solution, it is possible to purposefully regulate its thermal parameters, which opens up prospects for practical applications in the field of semiconductor technologies. REFERENCES [1] M.M. Qurbanov, M.M. Qocayev, S.C. Mammadov, A.B. Maharramov, E.N. Mammadov. Correction between thermal expansion, isothermal compressibility, and photoconductivity in solid solutions. Izv. RAN, Inorganic Materials, 2012, Vol. 48, No. 7, pp. 1–3. [2] M.M. Qurbanov, M.M. Qodjaev, A.M. Ahmedova. Debye temperature and elastic properties of solid solutions. Azerbaijan Journal of Physics Fizika, Vol. XXIII, No. 2, 2017, pp. 30–31. [3] I.V. Bodnar, A.A. Feshchenko, V.V. Khoroshko. Thermal expansion and thermal conductivity of solid solutions (In₂S₃)x•(AgIn₅S₈)₁−x. Physics and Technology of Semiconductors, 2021, Vol. 55, Issue 2, pp. 99–102. [4] M.K. Sharov Linear thermal expansion coefficient and Debye temperature of PbTe at high temperatures. Physics of the Solid State, 2022, Vol. 64, Issue 7, pp. 781–786. [5] G.D. Guseinov, S.S. Abdinbekov, M.M. Godjaev, D.G. Agamaliev. Unit cell parameters of solid solutions. Izv. AN USSR, Inorganic Materials, Moscow, 1988, Vol. 24, No. 1, pp. 144–145