Stability and thermal behavior of molybdenum disulfide nanotubes: Nonequilibrium molecular dynamics simulation using REBO potential

Abstract

This study is an attempt to perform equilibrium molecular dynamics and non-equilibrium molecular dynamics (NEMD) to evaluate the stability and thermal behavior of molybdenum disulfide nanotubes (MoS2NTs) by reactive empirical bond order potential. The stability of nanotubes, cohesive energy, isobaric heat capacity, and enthalpies of fusion in armchair and zigzag structures with different radii were calculated. The observed results illustrate that SWMoS2NTs, which have larger diameters, are more stable with more negative energy than the smaller ones. Moreover, it was found that the melting point is increased with an increase in the nanotube's radius. During the melting process, the structural transformation of nanotubes was investigated using a mean-square displacement and radial distribution function diagrams. Afterwards, using a NEMD simulation, the thermal conductivity of nanotubes with various diameters was calculated at a constant nanotube length. The obtained results show that the thermal conductivity coefficient increases with increasing nanotube diameters when the nanotube length is constant.

A DFT study of structural and thermal properties of 2D layers

“…The peak's positions shift as temperature increases further, wherein the MoMo, SS, and MoS peaks shift toward left (decreasing distance) slightly. At temperature between 2000 and 3000 K the most of the bonds in the structure break down which represent the liquid state of structure [49]. It is shown from the results SiC is most stable against temperature variations because it resists the temperature even at 4500 K as its melting point is about 4050 K after which RDF peaks diminish due to thermal broadening and bond breakage and structure is converted to liquid state.…”