Interlayer Registry Determines the Sliding Potential of Layered Metal Dichalcogenides: The case of 2H-MoS2

TL;DR

This paper introduces a geometrical registry index to predict the sliding energy landscape of 2H-MoS2, simplifying the study of interlayer friction and tribology in layered metal dichalcogenides.

Contribution

It presents a new geometrical parameter, the registry index, that correlates with the interlayer sliding energy landscape of 2H-MoS2, enabling efficient tribological analysis.

Findings

Registry index correlates with sliding energy landscape

Simplifies tribology studies of layered materials

Provides a computationally efficient method

Abstract

We provide a simple and intuitive explanation for the interlayer sliding energy landscape of metal dichalcogenides. Based on the recently introduced registry index (RI) concept, we define a purely geometrical parameter which quantifies the degree of interlayer commensurability in the layered phase of molybdenum disulphide (2HMoS2). A direct relation between the sliding energy landscape and the corresponding interlayer registry surface of 2H-MoS2 is discovered thus marking the registry index as a computationally efficient means for studying the tribology of complex nanoscale material interfaces in the wearless friction regime.