Mechanical behaviors of titanium nitride and carbide MXenes: A molecular dynamics study

Abstract MXenes have recently witnessed significant evolution and advances in terms of their applications in different areas such as flexible electronics, energy storage devices, and coatings. Here, the mechanical properties of both pristine and functionalized Tin+1CnO2 and Tin+1NnO2 (n = 1, 2) are investigated utilizing classical molecular dynamics simulations. For eight different MXene structures, the stress-strain curves are calculated including Young’s modulus, strength, and fracture strain. It is found that Ti2N holds the highest Young’s modulus with the value of 517 GPa while Ti3C2 has the lowest one with the amount of 133 GPa. In addition, the strongest MXene structure is Ti2N while the weakest strength belongs to the TiC3O2 structure. It is also found that oxidation, as a possible effect in experiments, enhances Young's modulus in Titanium Carbide MXenes, while it turns opposite for the Titanium Nitride ones. Both groups of structures however experience an increase in their fracture stress. Moreover, the effect of vacancy is probed on Young’s modulus and a linear correlation is presented versus the defect concentration for Ti2N structure. These results provide a benchmark to analyze the mechanical properties of MXenes for their potential applications in a wide range of nanoelectronics and nanomechanics.