Molecular Dynamics Simulations For Electron Irradiation Effects And Evolvement Of Materials Under Irradiation Effects

Knowing the electron irradiation effect is critical in understanding the behavior of materials under the examination of transmission electron microscopy (TEM). Elastic collision described by the Rutherford scattering model is introduced into molecular dynamics (MD) simulations to account for the evolvement of material structure. The dynamic nature, such as heating and sputtering, can be easily captured by MD methods with proper potentials. The platinum clusters are taken as the experimental subject, due to its high availability, activity and selectivity in a large amount of applications in the electronics and energy field. We design two series of simulations of platinum and graphene for the thermal effect and locality effect. Different sizes of Platinum clusters evolved different structures under electron irradiation and heating made the same effect, but not the same as grapheme. We made the related simulations in order to explain the difference. It not only verifies the thermal effect and locality effect of electron irradiation, but also proves the validity of the software.The damage of electron irradiation is a severe limitation of high-resolution electron microscopy, particularly for light elements materials. So it is important to understand the displacement cross section. We simulate the graphene under electron irradiation and calculate the number of lost atoms. The curve clearly shows a smooth onset of the damage around80keV, which agrees well with experimental observations.