Temperature-dependent failure of atomically thin MoTe2.

Abstract

In this study, we investigated the mechanical responses of molybdenum ditelluride (MoTe2) using molecular dynamics (MD) simulations. Our key focus was on the tensile behavior of MoTe2 with trigonal prismatic phase (2H-MoTe2) which was investigated under uniaxial tensile stress for both armchair and zigzag directions. Crack formation and propagation were examined to understand the fracture behavior of such material for varying temperatures. Additionally, the study also assesses the impact of temperature on Young's modulus and fracture stress-strain of a monolayer of 2H-MoTe2. The investigation was done using molecular dynamics (MD) simulations using Stillinger-Weber (SW) potentials. The tensile behavior was simulated for temperature for 10K and then from 100 to 600K with a 100-K interval. The crack propagation and formation of 10K and 300K 2H-MoTe2 for both directions at different strain rates was analyzed using Ovito visualizer. All the simulations were conducted using a strain rate of 10-4ps-1. The results show that the fracture strength of 2H-MoTe2 in the armchair and zigzag direction at 10K is 16.33 GPa (11.43 N/m) and 13.71429 GPa (9.46 N/m) under a 24% and 18% fracture strain, respectively. The fracture strength of 2H-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.