The effect of intrinsic strain on the thermal expansion behavior of Janus MoSSe nanotubes: a molecular dynamic simulation

Abstract

Abstract In this study, we conducted molecular dynamic simulations to investigate the thermal expansion behavior of Janus MoSSe nanotubes. We focused on understanding how the intrinsic strain in these nanotubes affects their thermal expansion coefficient (TEC). Interestingly, we found that Janus MoSSe nanotubes with sulfur (S) on the outer surface (MoSeS) exhibit a different intrinsic strain compared to those with selenium (Se) on the outer surface (MoSSe). In light of this observation, we explored the influence of this intrinsic strain on the TEC of the nanotubes. Our results revealed distinct trends for the TEC along the radial direction (TEC-r) and the axial direction (TEC-l x ) of the MoSSe and MoSeS nanotubes. The TEC-r of MoSeS nanotubes was found to be significantly greater than that of MoSSe nanotubes. Moreover, the TEC-l x of MoSeS nanotubes was smaller than that of MoSSe nanotubes. Further analysis showed that the TEC-r of MoSeS nanotubes decreased by up to 37% as the radius increased, while that of MoSSe nanotubes exhibited a slight increase with increasing radius. On the other hand, the TEC-l x of MoSeS nanotubes increased by as much as 45% with increasing radius, whereas that of MoSSe nanotubes decreased gradually. These opposite tendencies of the TECs with respect to the radius were attributed to the presence of intrinsic strain within the nanotubes. The intrinsic strain was found to play a crucial role in inducing thermally induced bending and elliptization of the nanotubes’ cross-section. These effects are considered key mechanisms through which intrinsic strain influences the TEC. Overall, our study provides valuable insights into the thermal stability of Janus nanotubes. By understanding the relationship between intrinsic strain and the thermal expansion behavior of nanotubes, we contribute to the broader understanding of these materials and their potential applications.