title: Pressure effect on stabilities of self-interstitials in HCP-zirconium.
abstract: The self-interstitial atoms (SIAs) mediate the evolution of micro-structures which is crucial in understanding the instabilities of hexagonal close packed (HCP) structures. Taking zirconium as a prototype, we investigate the pressure effect on the stabilities of SIAs using first-principles calculations based on density-functional theory. We found that the pressure greatly affects the stability of the SIAs. The SIAs in basal planes are more stable under pressure. The SIA configuration of the lowest formation energy changes from basal octahedral (BO) to octahedral (O) at a pressure of 21 GPa. The lowest formation enthalpy configuration switches from BO to S (split-dumbbell) at the pressure of 30 GPa. The formation volumes of SIAs decrease monotonically in response to an increase in pressure. Our results reveal that it is important to take pressure effects into account when predicting the micro-structural evolution of HCP structures.
authors.affiliation: Department of Mechanical, Aerospace and Nuclear Engineering, Rensselaer Polytechnic Institute, Troy, NY 12180, U.S.A.
authors.forename: Qing
authors.initials: Q
authors.lastname: Peng
authors.affiliation: Department of Mechanical, Aerospace and Nuclear Engineering, Rensselaer Polytechnic Institute, Troy, NY 12180, U.S.A.
authors.forename: Wei
authors.initials: W
authors.lastname: Ji
authors.affiliation: Department of Mechanical, Aerospace and Nuclear Engineering, Rensselaer Polytechnic Institute, Troy, NY 12180, U.S.A.
authors.forename: Jie
authors.initials: J
authors.lastname: Lian
authors.affiliation: Key Laboratory of Materials Physics, Institute of Solid State Physics, Chinese Academy of Sciences, Hefei 230031, China.
authors.forename: Xiao-Jia
authors.initials: XJ
authors.lastname: Chen
authors.affiliation: Department of Mechanical and Industrial Engineering, Northeastern University, Boston, MA 02115, U.S.A.
authors.forename: Hanchen
authors.initials: H
authors.lastname: Huang
authors.affiliation: Fundamental and Computational Sciences Directorate, Pacific Northwest National Laboratory, Richland, Washington 99352, U.S.A.
authors.forename: Fei
authors.initials: F
authors.lastname: Gao
authors.affiliation: Department of Mechanical, Aerospace and Nuclear Engineering, Rensselaer Polytechnic Institute, Troy, NY 12180, U.S.A.
authors.forename: Suvranu
authors.initials: S
authors.lastname: De