Mechanical behaviors of MoS nanowires under tension from molecular dynamics simulations

Abstract

As a new class of one-dimensional (1D) transition-metal monochalcogenides (TMMs) nanowires (NWs), the recently synthesized MoS NWs exhibit potential applications in two-dimensional integrated circuit. However, their mechanical behaviors remain almost unexplored. In this paper, the mechanical behaviors of MoS NWs under tensile loading are studied by classical molecular dynamics simulations together with first-principles calculations. A novel phase transformation is observed in the MoS NWs when the strain applied to them is larger than a critical value, which results in tension-induced hardening in their tensile modulus. Due to the existence of phase transformation, a complicated mechanical response is observed in MoS NWs during the entire loading process, which successively experiences the linear, plateau, stress hardening and fracture stages. The influence of various factors including the strain rate and temperature on the mechanical properties of MoS NWs such as phase transformation, Young’s modulus, fracture strength and fracture strain are also examined. The mechanical properties of MoS NWs obtained in this paper will be beneficial to their future applications in the semiconducting field. It is also expected that the results of the tension-induced phase transformation and its influence on the material properties observed in the present MoS NWs can be further extended to other 1D TMMs such as MoTe and SnSe NWs, since these 1D TMMs are found to possess the similar structure.