Synergistic coupling of structure, dynamics and electronics during the glass transition of rapidly quenched Li17Pb83: a GPW-AIMD study

Abstract

The glass transition in rapidly quenched Li17Pb83 remains a fundamental puzzle, particularly regarding the coupling among structural, dynamic and electronic properties in binary asymmetric alloy systems. Here, we perform ab initio molecular dynamics simulations during quenching to characterize its multi-scale evolution. A kinetic glass transition temperature Tking = 386.0 K is determined from the two-stage Arrhenius dependence of Li diffusion. Structural analysis reveals progressive enhancement of Pb short/medium-range order upon cooling, with the Pb–Pb coordination number increasing from 5.09 to 5.33 and the formation of Pb cage-like structures. Concurrently, Li dynamics transition from long-range hopping to localized rattling motions within these cages, as evidenced by van Hove correlation functions and phonon density of states. Electronic structure evolves synchronously. Pb-6p-dominated electron localization intensifies within the Pb cage network, accompanied by slight charge redistribution (Li: +0.136e to +0.130e, Pb −0.028e to −0.027e) and a marginal decrease in Pb–Pb bond order. These electronic changes are intimately linked to structural ordering and dynamic slowdown, providing atomic-scale evidence for the correlated nature of the glass transition. We propose a synergistic structure-dynamics-electron mechanism, Pb cage densification as the structural foundation, Li mobility arrest as the dynamic signature, and Pb-6p localization as the electronic feature that collectively accompanies the dynamic freezing of interstitial Li atoms. This work complements classical glass transition theories with atomic-scale electronic evidence and offers a multi-dimensional characterization approach for asymmetric binary amorphous alloys.