Using dissipation models based on Akhiezer theory, we analyze the microscopic origin of nonlinearity in intrinsic loss of a single layer MoS2. We study the intrinsic dissipation of single layer MoS2 under axial and flexural mode of deformation using molecular dynamics (MD) simulation. We compare the amplitude scaling of intrinsic dissipation for both the cases with our proposed model. In the axial deformation case, we found a higher (4th) order dependence of dissipation on the strain amplitude. This nonlinearity is shown to stem from the strain dependence of the phonon mode Grüneisen parameter (PMGP) and is accounted for in our dissipation model. In the flexural deformation case, dissipation is found to have a stronger dependence (≥4) on the amplitude of the transverse motion. This nonlinearity can be explained by considering the coupling between out-of-plane motion and in-plane stretching. The proposed model for the flexure deformation case, which accounts for both kinds of nonlinearity, provides a good estimate of dissipation.
ASJC Scopus subject areas
- Chemical Engineering(all)