Ab initio molecular dynamics simulations of ion-solid interactions in zirconate pyrochlores
In this paper, an ab initio molecular dynamics method is employed to study low energy recoil events in zirconate pyrochlores (A2Zr2O7, A = La, Nd and Sm). It shows that both cations and anions in Nd2Zr2O7 and Sm2Zr2O7 are generally more likely to be displaced than those in La2Zr2O7. The damage end states mainly consist of Frenkel pair defects, and the Frenkel pair formation energies in Nd2Zr2O7 and Sm2Zr2O7 are lower than those in La2Zr2O7. These results suggest that the order–disorder structural transition more easily occurs in Nd2Zr2O7 and Sm2Zr2O7 resulting in a defect-fluorite structure, which agrees well with experimental observations. Our calculations indicate that oxygen migration from 48f and 8b to 8a sites is dominant under low energy irradiation. A number of new defects, including four types of cation Frenkel pairs and six types of anion Frenkel pairs, are revealed by ab initio molecular dynamics simulations. The present findings may help to advance the fundamental understanding of the irradiation response behavior of zirconate pyrochlores.
- Authors:
-
[1]
; [2]
; [3]
; [1]
- University of Electronic Science and Technology of China, Chengdu (China)
- Univ. of Tennessee, Knoxville, TN (United States); Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)
- Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Univ. of Tennessee, Knoxville, TN (United States)
- Publication Date:
- Grant/Contract Number:
- AC05-00OR22725
- Type:
- Accepted Manuscript
- Journal Name:
- Acta Materialia
- Additional Journal Information:
- Journal Volume: 87; Journal ID: ISSN 1359-6454
- Publisher:
- Elsevier
- Research Org:
- Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)
- Sponsoring Org:
- USDOE Office of Science (SC), Basic Energy Sciences (BES) (SC-22)
- Country of Publication:
- United States
- Language:
- English
- Subject:
- 36 MATERIALS SCIENCE; 38 RADIATION CHEMISTRY, RADIOCHEMISTRY, AND NUCLEAR CHEMISTRY; Computer simulation; Zirconate pyrochlores; Radiation effects; Charge transfer
- OSTI Identifier:
- 1265303
- Alternate Identifier(s):
- OSTI ID: 1250964
- Free Publicly Accessible Full Text
- Accepted Manuscript (Publisher)
-
Accepted Manuscript (DOE)
- Publisher's Version of Record
- https://doi.org/10.1016/j.actamat.2015.01.019