The Surface Free Energies of Solid Chemical Elements: Calculation from Internal Free Enthalpies of Atomization

Abstract

It is pointed out that the experimentally-measured quantity usually termed "surface free energy" is in fact a part of the free enthalpy which is due to the presence of the surface (referred to unit surface). This quantity, denoted by γ_i^o for the polycrystalline solid chemical element i, is connected to the internal free enthalpy of atomization ΔG_a,i^* by the relation γ_i^o_i^o=α_i^oΔG_a,i^* where _i^o is the molar surface area, and α_i^o is a constant. Its physical meaning is given to a relatively good approximation. Approximate methods of calculation based on experimental data give values of α_i^o at any temperature for metallic, semimetallic and covalently-bonded solid chemical elements. Using these procedures, the values of γ_i^o at 298.2 K and at the melting temperature are tabulated.