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Title: Influence of grain growth on the structural properties of the nanocrystalline Gd 2 Ti 2 O 7

Authors:
; ; ; ;
Publication Date:
Sponsoring Org.:
USDOE
OSTI Identifier:
1396892
Grant/Contract Number:
SC0016584; 2051/FNPDR/2015
Resource Type:
Journal Article: Publisher's Accepted Manuscript
Journal Name:
Journal of Nuclear Materials
Additional Journal Information:
Journal Volume: 487; Journal Issue: C; Related Information: CHORUS Timestamp: 2017-10-04 15:32:13; Journal ID: ISSN 0022-3115
Publisher:
Elsevier
Country of Publication:
Netherlands
Language:
English

Citation Formats

Kulriya, P. K., Yao, Tiankai, Scott, Spencer Michael, Nanda, Sonal, and Lian, Jie. Influence of grain growth on the structural properties of the nanocrystalline Gd 2 Ti 2 O 7. Netherlands: N. p., 2017. Web. doi:10.1016/j.jnucmat.2017.02.032.
Kulriya, P. K., Yao, Tiankai, Scott, Spencer Michael, Nanda, Sonal, & Lian, Jie. Influence of grain growth on the structural properties of the nanocrystalline Gd 2 Ti 2 O 7. Netherlands. doi:10.1016/j.jnucmat.2017.02.032.
Kulriya, P. K., Yao, Tiankai, Scott, Spencer Michael, Nanda, Sonal, and Lian, Jie. Sat . "Influence of grain growth on the structural properties of the nanocrystalline Gd 2 Ti 2 O 7". Netherlands. doi:10.1016/j.jnucmat.2017.02.032.
@article{osti_1396892,
title = {Influence of grain growth on the structural properties of the nanocrystalline Gd 2 Ti 2 O 7},
author = {Kulriya, P. K. and Yao, Tiankai and Scott, Spencer Michael and Nanda, Sonal and Lian, Jie},
abstractNote = {},
doi = {10.1016/j.jnucmat.2017.02.032},
journal = {Journal of Nuclear Materials},
number = C,
volume = 487,
place = {Netherlands},
year = {Sat Apr 01 00:00:00 EDT 2017},
month = {Sat Apr 01 00:00:00 EDT 2017}
}

Journal Article:
Free Publicly Available Full Text
Publisher's Version of Record at 10.1016/j.jnucmat.2017.02.032

Citation Metrics:
Cited by: 1work
Citation information provided by
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  • Ab initio total energy calculations have been performed to study the phase stability of Gd 2Ti 2O 7 and Gd 2Z 2O 7 pyrochlores over the pressure range from 0 to 60 GPa. Both compounds are unstable under pressure, and phase transformations to the defect-cotunnite structure are predicted. The phase transformation pressure of 43.6 GPa for Gd 2Ti 2O 7 is considerably larger than the value of 13 GPa for Gd 2Zr 2O 7, in good agreement with experiments. The decreased structural stability of Gd 2Zr 2O 7 under pressure, relative to Gd 2Ti 2O 7, is a consequence ofmore » the lower compressibility of the bond and the higher compressibility of the bond. In addition, the Gd 4f electrons are found to have only a small effect in determining the pressure induced phase transformation.« less
  • A potentially enhanced radiation resistance of nanocrystalline materials, as a consequence of the high density of interfaces and surfaces, has attracted much attention both to understand the fundamental role of these defect sinks and to develop them for high-radiation environments. Here, irradiation response of nanocrystalline A 2Ti 2O 7 (A = Gd, Ho and Lu) pyrochlore powders with grain sizes of 20–30 nm was investigated by 1-MeV Kr 2+ ion bombardment. In situ transmission electron microscopy (TEM) revealed that the critical amorphization fluence for each nanocrystalline compound at room temperature was greater than that for their coarse-grained counterparts, indicating anmore » enhanced amorphization resistance. The effect of temperature on the irradiation response of one of these compounds, nanocrystalline Lu 2Ti 2O 7, was further examined by performing ion irradiation at an elevated temperature range of 480–600 K. The critical amorphization temperature (T c) was found to be noticeably higher in nanocrystalline Lu 2Ti 2O 7 (610 K) than its coarse-grained counterpart (480 K), revealing that nanocrystalline Lu 2Ti 2O 7 is less resistant to amorphization compared to its coarse-grained phase under high temperatures. We interpret these results with the aid of atomistic simulations. Molecular statics calculations find that cation antisite defects are less energetically costly to form near surfaces than in the bulk, suggesting that the nanocrystalline form of these materials is generally less susceptible to amorphization than coarse-grained counterparts at low temperatures where defect kinetics are negligible. In contrast, at high temperatures, the annealing efficiency of antisite defects by cation interstitials is significantly reduced due to the sink properties of the surfaces in the nanocrystalline pyrochlore, which contributes to the observed higher amorphization temperature in the nano-grained phase than in coarse-grained counterpart. Altogether, these results provide new insight into the behavior of nanocrystalline materials under irradiation.« less