Programme

P.46 -- Posters, VCTP-51

Date: Tuesday, 4 August 2026

Time: 09:30 - 10:30

Study of diffusion in sodium silicate glasses by molecular dynamics simulation

Pham Thi Lien (1), Tran Duc Hiep (2), Nguyen Thi Thao (2)

(1) Faculty of Applied Sciences, University of Economics -Technology for Industries, Hanoi, Vietnam (2) Faculty of Physics, Hanoi National University of Education, Hanoi, Vietnam

The diffusion process in sodium silicate glasses was investigated using molecular dynamics simulation. The result shows that unlike Si atoms, which remain within the same Si-O coordination cells during 150 ps, Na atoms frequently displace between different Na-O coordination cells (CC). By analyzing the set of CCs visited by Na atoms, the simulation identifies two displacement types resembling drift and activated hopping. We have established the expression for diffusion constant D, showing it is proportional F2d2/tCC where tCC, d2, and F2 represent the residence time in CC, the mean square displacement per central CC, and the correlation factor, respectively. For systems at the same temperature, both D and the drift/hop ratio reduce with increasing SiO2 content. Conversely, for systems with the same SiO2 content, a decrease in temperature leads to a reduction in D but an increase in the drift/hop ratio.

Presenter: Nguyen Thi Thao