Atomistic simulations of nanoindentation on the basal plane of crystalline molybdenum disulfide (MoS2)

Abstract

In the present work, nanoindentation on the basal surface of a crystalline molybdenum disulfide (MoS 2 ) thin film is investigated by molecular statics (MS) calculations. A previously parameterized interatomic potential combining the reactive empirical bond-order and Lennard-Jones potentials is implemented into the LAMMPS molecular simulation package and refined for improved prediction of the mechanical properties of MoS 2 at athermal conditions. Nanoindentation simulations are performed using three indenter sizes with specific focus on the incipient plastic deformation event within the MoS 2 single crystal. MS calculations show that a local phase transformation occurs beneath the indenter at plastic yield without the presence of broken Mo–S bonds. The structural characteristics of the phase transformation are captured using a slip vector analysis. The nanoindentation simulations provide insight into the mechanical response of MoS 2 during contact deformation characteristic of both synthesis and application for better design of MoS 2 nanoparticle lubricants.