Programme

P.2 -- Posters, VCTP-51

Date: Tuesday, 4 August 2026

Time: 09:30 - 10:30

Effects of temperature and SiO₂ content on the structure of lithium silicate glasses: A Molecular dynamics simulation study

Pham Thi Lien (1), Nguyen Thi Thao (2,3), Pham Khac Hung (4)

(1) Faculty of Applied Sciences, University of Economics-Technology for Industries, Hanoi, Vietnam; (2) Faculty of Physics, Hanoi National University of Education, Hanoi, Vietnam; (3) Institute of Natural Science, Hanoi National University of Education, Hanoi, Vietnam; (4) Faculty of Engineering Physics, Hanoi University of Science and Technology, Hanoi, Vietnam

Molecular dynamics simulations were carried out to investigate the effects of temperature and composition on the structural characteristics of lithium silicate glasses with three representative compositions, denoted as LS1, LS2, and LS4. The simulations were performed over the temperature range of 300–973 K. The reliability of the simulated models was evaluated by comparing the calculated densities, radial distribution functions, and structure factors with available experimental data, showing good agreement. The results reveal that the Si–O network remains locally stable for all investigated compositions and temperatures. The Si–O bond length is approximately 1.55–1.60 Å, and the Si–O coordination number remains close to 4, confirming the persistence of SiO₄ tetrahedral units in the glass network. In contrast, the Li–O coordination environment is more broadly distributed, mainly involving LiO₄ and LiO₅ units, which reflects the role of Li⁺ ions as network modifiers. Increasing SiO₂ content enhances the polymerization of the silicate network, as evidenced by the increase in O–Si coordination and the decrease in the number of non-bridging oxygens per tetrahedron. Temperature mainly affects the medium-range structural order. With increasing temperature, the intensity of the first sharp diffraction peak decreases and its width increases, whereas its position remains nearly unchanged at q ≈ 1.75–1.78 Å⁻¹. Meanwhile, the main peak located at q ≈ 2.7 Å⁻¹ exhibits only minor changes, indicating that the short-range structure is much less sensitive to temperature. These findings demonstrate that composition primarily controls the network topology of lithium silicate glasses, while temperature mainly weakens the medium-range order without significantly altering the local Si–O structure.

Presenter: Pham Thi Lien