Papers by Author: Li Yang

Abstract: A reactive interatomic potential based on an analytical bond-order scheme is developed for hexagonal close-packed (hcp) scandium, and the model is fitted to the lattice parameters, elastic constants, cohesive energy and vacancy formation energy of scandium. The potential was used to calculate the structural energy differences of bcc-hcp, fcc-hcp, sc-hcp and diamond-hcp, as well as self-interstitial atom (SIA) formation energy, vacancy migration energy, divacancy binding energy, surface energy and stacking fault energy. The developed potential is shown to be able to reproduce energetics and structural properties of hcp-scandium.

Abstract: Molecular dynamics (MD) methods are utilized to study the displacement cascades in α-Fe containing different concentrations of substitutional He atoms. Primary knock-on atom (PKA) energies, Ep, from o.5 keV to 20 keV are considered at a temperature of 100 K and 600 K, and the results are compared with those performed in pure α-Fe. There are distinct differences in the number and size of defect clusters within displacement cascades with and without substitutional helium atoms. Particularly, the number and size of helium-vacancy clusters generally increase with increasing helium concentration and PKA energy. However, the number of He-vacancy (He-V) clusters increases with increasing temperature, the mean size of He-V clusters is independent on temperature for the same He concentration and energy recoils.