Temperature Dependent Failure of Atomically Thin MoTe2

TL;DR

This paper investigates how temperature affects the mechanical failure of monolayer MoTe2 using molecular dynamics simulations, revealing temperature-dependent variations in fracture strength and crack propagation behaviors.

Contribution

It provides the first systematic analysis of temperature effects on fracture behavior and mechanical properties of monolayer MoTe2 through detailed MD simulations.

Findings

Fracture strength decreases with increasing temperature.

Crack propagation differs between armchair and zigzag directions.

Young's modulus is affected by temperature changes.

Abstract

In this study, we systematically investigated the mechanical responses of monolayer molybdenum ditelluride (MoTe2) using molecular dynamics (MD) simulations. The tensile behavior of trigonal prismatic phase (2H phase) MoTe2 under uniaxial strain was simulated in the armchair and zigzag directions. We also investigated the crack formation and propagation in both armchair and zigzag directions at 10K and 300K to understand the fracture behavior of monolayer MoTe2 at different temperatures. The MD simulations show clean cleavage for the armchair direction, and the cracks were numerous and scattered in the case of the zigzag direction. Finally, we investigated the effect of temperature on Young's modulus and fracture stress of monolayer MoTe2. The results show that at a strain rate of 10^-4 ps^-1, the fracture strength of monolayer MoTe2 in the armchair and zigzag directions at 10K is 16.33 GPa (11.43 N/m) and 13.71 GPa (9.46 N/m) under a 24% and 18% fracture strain, respectively. The fracture strength of monolayer MoTe2 in the armchair and zigzag direction at 600K is 10.81 GPa (7.56 N/m) and 10.13 GPa (7.09 N/m) under a 12.5% and 12.47% fracture strain, respectively.