Large-scale atomistic simulations using the reactive empirical bond order force field approach is implemented to investigate thermal and mechanical properties of single-layer (SL) and multilayer (ML) molybdenum disulfide (${\mathrm{MoS}}_2$). The amplitude of the intrinsic ripples of SL ${\mathrm{MoS}}_2$ are found to be smaller than those exhibited by graphene (GE). Furthermore, because of the van der Waals interaction between layers, the out-of-plane thermal fluctuations of ML ${\mathrm{MoS}}_2$ decreases rapidly with increasing number of layers. This trend is confirmed by the buckling transition due to uniaxial stress which occurs for a significantly larger applied tension as compared to graphene. For SL ${\mathrm{MoS}}_2$, the melting temperature is estimated to be 3700 K which occurs through dimerization followed by the formation of small molecules consisting of two to five atoms. When different types of vacancies are inserted in the SL ${\mathrm{MoS}}_2$ it results in a decrease of both the melting temperature as well as the stiffness.

• Received 1 October 2014
• Revised 3 December 2014

DOI:https://doi.org/10.1103/PhysRevB.91.014101