Grand potential in thermodynamics of solid bodies and surfaces

TL;DR

This paper introduces a new concept of grand thermodynamic potential for solids, unifying the definition of surface free energy with that of fluids, independent of dividing surface location.

Contribution

It proposes a generalized grand thermodynamic potential for solids that is independent of the dividing surface and applicable to both fluids and solids.

Findings

Defines a new grand potential for solids at equilibrium with solutions.

Shows the potential is independent of the dividing surface location.

Unifies the concept of surface free energy for fluids and solids.

Abstract

Using the chemical potential of a solid in a dissolved state or the corresponding component of the chemical potential tensor at equilibrium with the solution, a new concept of grand thermodynamic potential for solids has been suggested. This allows generalizing the definition of Gibbs' quantity $\sigma$ (surface work often called the solid-fluid interfacial free energy) at a planar surface as an excess grand thermodynamic potential per unit surface area that (1) does not depend on the dividing surface location and (2) is common for fluids and solids.