Mechanical and Tribological Properties of Layered Materials Under High Pressure: Assessing the Importance of Many-Body Dispersion Effects

TL;DR

This study demonstrates that many-body dispersion effects are crucial for accurately modeling the mechanical and tribological behavior of layered materials under high pressure, using advanced simulations and theoretical calculations.

Contribution

It introduces a new classical interlayer potential fitted with many-body dispersion effects, improving the prediction of layered materials' properties under high pressure.

Findings

Many-body dispersion effects significantly influence mechanical response.

The model accurately reproduces experimental data.

Friction properties are sensitive to many-body dispersion effects.

Abstract

The importance of many-body dispersion effects in layered materials subjected to high external loads is evaluated. State-of-the-art many-body dispersion density functional theory calculations performed for graphite, hexagonal boron nitride, and their hetero-structures were used to fit the parameters of a classical registry-dependent interlayer potential. Using the latter, we performed extensive equilibrium molecular dynamics simulations and studied the mechanical response of homogeneous and heterogeneous bulk models under hydrostatic pressures up to 30 GPa. Comparison with experimental data demonstrates that the reliability of the many-body dispersion model extends deep into the sub-equilibrium regime. Friction simulations demonstrate the importance of many-body dispersion effects for the accurate description of the tribological properties of layered materials interfaces under high pressure.