Absolute surface energy determination

TL;DR

This paper introduces a straightforward method for experimentally determining absolute surface energies using equilibrium shape analysis and thermal fluctuation data, demonstrated on Si(111) at high temperature.

Contribution

The paper presents a novel, simple approach combining shape measurements and fluctuation analysis to measure absolute surface free energy.

Findings

Estimated surface energy of Si(111) between 0.59 and 0.83 J/m² at 1373 K.

Method applicable when all orientations are present and surface stress is isotropic.

Provides a practical way to measure surface energies experimentally.

Abstract

Experimental determination of absolute surface energies remains a challenge. We propose a simple method based on two independent measurements on 3D and 2D equilibrium shapes completed by the analysis of the thermal fluctuation of an isolated step. Using then basic equations (Wulff' theorem, Gibbs-Thomson equation, thermodynamics fluctuation of an isolated step) allows us to extract the absolute surface free energy of a singular face. The so-proposed method can be applied when (i) all orientations exists on the equilibrium shape, (ii) the surface stress is isotropic. This procedure is applied to the case of Si(111) where we find a value between 0.59 Jm-2 and 0.83 Jm-2 at 1373 K.