Interface and structural rearrangement during crystal growth from molecular dynamics simulations
Phys. Rev. B 113, 054202 – Published 24 February, 2026
DOI: https://doi.org/10.1103/86zh-2qtq
Abstract
Understanding crystallization mechanisms at the atomic scale is critical for advancing glass-ceramics design and improving the predictive accuracy of classical nucleation theory (CNT). While CNT assumes sharp interfaces and isolated atomic jumps during crystal growth, emerging evidence suggests the presence of diffuse interfaces and cooperative atomic rearrangements. However, experimental characterization of interfacial regions remains challenging due to their nanoscale dimensions and dynamic nature. In this study, molecular dynamics (MD) simulations were employed to investigate the structural and dynamic evolution of the interface during the growth of lithium aluminosilicate (LAS) crystals, a widely used glass-ceramic system. Our findings reveal the existence of two distinct interfaces: (1) a pre-ordered structural interface with a temperature-dependent width, and (2) a diffusion interface characterized by gradients in atomic mobility. Contrary to CNT assumptions, crystal growth proceeds via cooperative rearrangements of network-forming atoms, with ring structures acting as key units of ordering. The width of the structural interface was found to increase with decreasing temperature, while the diffusion interface narrowed, highlighting the coupling between thermodynamic and kinetic factors during crystallization. These results refine existing crystallization theories by incorporating atomic-scale insights and provide a foundation for designing glass-ceramics with tailored properties.
