Dynamics of vacancies in two-dimensional Lennard-Jones crystals

ORAL

Abstract

Vacancies represent an important class of crystallographic defects, and their behaviors can be strongly coupled with relevant material properties. We report the rich dynamics of vacancies in two-dimensional Lennard-Jones crystals in several thermodynamic states. Specifically, we numerically observe significantly faster diffusion of the 2-point vacancy with two missing particles in comparison with other types of vacancies; it opens the possibility of doping 2-point vacancies into atomic materials to enhance atomic migration. In addition, the resulting dislocations in the healing of a long vacancy suggest the intimate connection between vacancies and topological defects that may provide an extra dimension in the engineering of defects in extensive crystalline materials for desired properties.

*We thank the financial support from the U.S. Department of Commerce, National Institute of Standards and Technology, the Office of the Director of Defense Research and Engineering (DDR\&E) and the Air Force Office of Scientific Research.

–

Authors

  • Zhenwei Yao

    • Northwestern University
    • Northwestern Univ

  • Monica Olvera de la Cruz

    • Northwestern University
    • Northwestern Univ
    • Department of Materials Science and Engineering, Northwestern University
    • Department of Materials Science and Engineering, Northwestern University, Evanston, Illinois 60208, United States
    • Department of Materials Science and Engineering, Northwestern University, Evanston, IL 60208
    • Department of Materials Science and Engineering, Northwestern University, Evanston, Illinois 60208, USA