Test Of Mean First Passage Time Method And Classical Nucleation Theory On Crystal Nucleation In A Lennard Jones Liquid

Test of Mean First Passage Time Method and Classical Nucleation Theory on Crystal Nucleation in a Lennard-Jones Liquid

Classical Nucleation Theory in Multicomponent Systems

Nucleation is the initial step of every first-order phase transition, and most phase transitions encountered both in everyday life and industrial processes are of the first-order. Using an elegant classical theory based on thermodynamics and kinetics, this book provides a fully detailed picture of multi-component nucleation. As many of the issues concerning multi-component nucleation theory have been solved during the last 10-15 years, it also thoroughly integrates both fundamental theory with recent advances presented in the literature. Classical Nucleation Theory in Multicomponent Systems serves as a textbook for advanced thermodynamics courses, as well as an important reference for researchers in the field. The main topics covered are: the basic relevant thermodynamics and statistical physics; modelling a molecular cluster as a spherical liquid droplet; predicting the size and composition of the nucleating critical clusters; kinetic models for cluster growth and decay; calculating nucleation rates; and a full derivation and application of nucleation theorems that can be used to extract microscopic cluster properties from nucleation rate measurements. The assumptions and approximations needed to build the classical theory are described in detail, and the reasons why the theory fails in certain cases are explained. Relevant problems are presented at the end of each chapter.

Classical Nucleation Theory in the Phase Field Crystal Model

"An understanding of polycrystalline materials, ranging from alloys to certain ceramics and polymers and beyond, is of great importance for modern society. These materials typically form through the process of nucleation, a thermally activated phase transition. The numerical modeling of this phase transition is problematic for traditional numerical techniques: the commonly used phase field methods' resolution does not extend to the atomic scales at which nucleation takes places, while atomistic methods such as Molecular Dynamics are incapable of scaling to the mesoscale regime where late-stage growth and structure formation takes place following earlier nucleation. As such, there is interest in examining whether the Phase Field Crystal (PFC) model, which attempts to bridge the atomic and mesoscale regimes, is capable of modeling nucleation. In this work, we numerically calculate nucleation rates and incubation times in the PFC model. We show qualitative agreement with classical nucleation theory (CNT), a single-variable stochastic model. Notably, we show that nucleation rates in the PFC model are time-dependent. We also examine the form and behavior of nuclei at early formation times, finding disagreement with some basic assumptions of CNT. We then argue that a quantitatively correct nucleation theory for the PF Cmodel would require extending CNT to a multi-variable theory." --