Vacancy theory of melting

TL;DR

This paper develops a vacancy-based theory of melting in metals, proposing a discontinuous phase transition model that extends Frenkel's vacancy mechanism, contrasting with traditional continuous transition descriptions.

Contribution

It introduces a strict, non-equilibrium thermodynamics approach to vacancy theory, providing a new framework for understanding metal melting as a discontinuous phase transition.

Findings

Melting can be described as a discontinuous phase transition.

Traditional Frenkel's model describes melting as continuous at low vacancy concentrations.

Extended vacancy states influence vacancy mobility and melting behavior.

Abstract

The features of alternative approach of non-equilibrium evolution thermodynamics are shown on the example of theory of vacancies by opposed to the classic prototype of Landau theory. On this foundation a strict theory of the melting of metals, based on development of Frenkel ideas about the vacancy mechanism of such phenomena, is considered. The phenomenon of melting is able to be described as a discontinuous phase transition, while the traditional Frenkel's solution in the region of low-concentration of vacancies can describe such transition only as continuous one. The problem of limiting transition of shear modulus to zero values in the liquid state, as well as the problem of the influence of extended state of vacancies on their mobility, is discussed.