Theoretical Prediction of Crystallization Kinetics of a Supercooled Fluid
Speaker
Prof. Xue-Yu Song
Iowa State University, USA
Abstract

Crystallization of a supercooled fluid is a ubiquitous process in nature. Despite a plethora of studies the fundamental mechanism behind the crystallization process is still not well understood. In this letter we show that the classical description for nucleation is capable of predicting the nucleation barrier when the curvature correction to the interfacial free energy is accounted for. We develop a theoretical methodology based on the interfacial excess thermodynamic properties to extract the first order curvature correction to the crystal-liquid interfacial free energy. The correction parameter ($\delta$), which is analogues to the Tolman length in a liquid-vapor interface, is found to be $\delta=0.48\pm 0.05$ for a Lennard-Jones (LJ) fluid. We show that this curvature correction is crucial in predicting the nucleation barrier when the size of the crystal nucleus is small. The driving force ($\Delta\mu$) corresponding to the same supercooled condition is also calculated by combining the simulated data with a classical density functional theory. With these major developments the predicted nucleation barrier of a supercooled LJ fluid is in excellent agreement with the simulated nucleation barrier.