title: Point defect-grain boundary interactions in MgO: an atomistic study.
abstract: The way in which point defects interact with grain boundaries in oxides is important for understanding radiation damage evolution, sintering, and many other technologically important applications. Here, we examine how vacancies interact with three different grain boundaries in MgO, chosen as a model oxide ceramic. Further, we compare the vacancy interaction with both pristine (as constructed) and 'damaged' boundaries, in which excess interstitials are placed in the boundary plane to mimic the structure after a damage event. We find that the excess interstitials significantly change the interaction of the vacancies with the boundaries and that this change is sensitive to the atomic structure of the boundary. We further observe that complex electrostatic effects arise that can dominate the interaction. These results show that, as boundaries absorb defects, their interaction with other defects will change dramatically.
authors.affiliation: Materials Science and Technology Division, Los Alamos National Laboratory, Los Alamos, NM 87545, USA. blas@lanl.gov
authors.forename: Blas Pedro
authors.initials: BP
authors.lastname: Uberuaga
authors.forename: Xian-Ming
authors.initials: XM
authors.lastname: Bai
authors.forename: Pratik P
authors.initials: PP
authors.lastname: Dholabhai
authors.forename: Natalie
authors.initials: N
authors.lastname: Moore
authors.forename: Dorothy M
authors.initials: DM
authors.lastname: Duffy
mesh_terms: D000042:Absorption; D003198:Computer Simulation; D008277:Magnesium Oxide / Q000737:chemistry*; D008956:Models, Chemical; D008958:Models, Molecular; D008968:Molecular Conformation; D013499:Surface Properties
chemical_list: D008277:Magnesium Oxide