Configurational density of states and melting of simple solids

TL;DR

This paper models the melting transition of simple solids using a configurational density of states approach, reproducing key features like metastability and superheating limits through a simplified analytical framework.

Contribution

It introduces a piecewise model of the configurational density of states that captures the first-order phase transition and metastable regions during melting.

Findings

Reproduces metastable regions and superheating limits in the model.

Provides transcendental equations linking melting point and specific heat.

Shows that essential features of Z curves can be derived from simple configurational models.

Abstract

We analyze the behavior of the microcanonical and canonical caloric curves for a piecewise model of the configurational density of states of simple solids, in the context of melting from the superheated state, as realized numerically in the Z-method via atomistic molecular dynamics. A first-order phase transition with metastable regions is reproduced by the model, being therefore useful to describe aspects of the melting transition. Within this model, transcendental equations connecting the superheating limit, the melting point, and the specific heat of each phase are presented and numerically solved. Our results suggest that the essential elements of the microcanonical Z curves can be extracted from simple modeling of the configurational density of states.