Computing the Tolman length for solid-liquid interfaces

TL;DR

This paper introduces a new atomistic simulation method to directly compute the Tolman length for solid-liquid interfaces, addressing a longstanding challenge in understanding curvature effects on interfacial free energy.

Contribution

The authors develop a general approach to measure the Tolman length directly from simulations, improving accuracy over previous indirect methods.

Findings

Successfully computed the Tolman length for a model potential

Validated the method against less rigorous approaches

Provided insights into curvature dependence of solid-liquid interfaces

Abstract

The curvature dependence of interfacial free energy, which is crucial in quantitatively predicting nucleation kinetics and the stability of bubbles and droplets, can be described in terms of the Tolman length {\delta}. For solid-liquid interfaces, however,{\delta} has never been computed directly due to various theoretical and practical challenges. Here we present a general method that enables the direct evaluation of the Tolman length from atomistic simulations of a solid-liquid planar interface in out-of-equilibrium conditions. This method works by first measuring the surface tension from the amplitude of thermal capillary fluctuations of a localized version of Gibbs dividing surface, and bythen computing the free energy difference between the surface of tension and the equimolar dividing surface. For benchmark purposes, we computed {\delta}for a model potential, and compared the results to less rigorous indirect approaches.