Refining interface stress measurement in nanomultilayers through layer corrugation and interface roughness corrections

TL;DR

This paper develops models that include layer corrugation and interface roughness to improve interface stress measurements in nanomultilayers, revealing that atomic-scale effects also significantly influence stress levels.

Contribution

The authors introduce new models accounting for corrugation and roughness, enhancing the accuracy of interface stress measurements in nanomultilayers.

Findings

Ignoring corrugation and roughness inflates stress measurements by up to 0.4 J/m^2.

Atomic-scale phenomena like intermixing dominate extreme stress levels.

Balancing bilayer counts and roughness ratios improves stress quantification.

Abstract

We introduce new models that incorporate layer corrugation and interface roughness into standard approaches for measuring interface stress in nanomultilayers (NMLs). Applied to Cu/W NMLs, these models show that ignoring such features can inflate measured interface stress by up to 0.4 J/m^2. However, corrugation and roughness alone cannot account for the extreme stresses reported, suggesting that atomic-scale phenomena (e.g., intermixing and metastable phase formation at the interfaces) dominate. These findings highlight the importance of balancing bilayer counts and thickness-to-roughness ratios for reliable stress quantification, providing a practical pathway to designing and characterizing advanced nanocomposite coatings with improved accuracy.