A Thermodynamic Model for Thermomigration in Metals

TL;DR

This paper presents a thermodynamic model for understanding thermomigration of interstitial hydrogen in metals, highlighting the significance of electronic effects and validating the model with experimental data.

Contribution

It introduces a comprehensive mechanistic model based on irreversible thermodynamics that incorporates electronic effects, advancing the understanding of solute localization in metals.

Findings

Electron-wind effect significantly influences thermomigration direction.

The model aligns well with experimental data.

Atomistic models may overlook key electronic factors.

Abstract

We investigate the mechanisms involved in the thermomigration of interstitial hydrogen in metals. Using irreversible thermodynamics, we develop a comprehensive mechanistic model to capture the controlling effects. Crucially, through validation against published experimental data, our results demonstrate that an electron-wind effect plays a significant role, particularly for materials in which the thermomigration direction matches the heat flux. These findings provide new insights into the factors that affect the localisation of solutes in metals. Moreover, our results indicate that atomistic models may be inadequate for detailed thermomigration studies due to the omission of electronic effects.