Alkaline-Earth Doped Effect on Oxygen Vacancy Migration in Monoclinic Lanthanum Germanate: First-Principles Calculation

2013 ◽  
Vol 57 (1) ◽  
pp. 1077-1083
Author(s):  
T. P. T. Linh ◽  
M. Sakaue ◽  
M. Alaydrus ◽  
T. D. K. Wungu ◽  
S. M. Aspera ◽  
...  
2007 ◽  
Vol 46 (10B) ◽  
pp. 7136-7140 ◽  
Author(s):  
Hiroki Moriwake ◽  
Tsukasa Hirayama ◽  
Yuichi Ikuhara ◽  
Isao Tanaka

2011 ◽  
Vol 485 ◽  
pp. 23-26 ◽  
Author(s):  
Atsushi Honda ◽  
Shin'ichi Higai ◽  
Takafumi Okamoto ◽  
Noriyuki Inoue ◽  
Yasuhiro Motoyoshi ◽  
...  

We performed first-principles calculations to examine the interaction among rare-earth (RE), alkaline-earth (AE) elements and oxygen vacancy (VO) in BaTiO3, in order to clarify the combined effects of VO trapping by two different elements. It was found that there is a synergistic effect of VO trapping by RE at Ba site and AE at Ti site, so that the co-doping is effective to improve insulating reliability of BaTiO3. We also verified that the local atomic structures around dopants obtained by calculations well agree with that obtained experimentally by extended X-ray absorption fine structure (EXAFS) analyses. The present work is the first one to clarify the structural environment around dopants including VO by both theoretical and experimental approaches.


Author(s):  
Qiang Zhao ◽  
Zheng Zhang ◽  
Yang Li ◽  
Xiaoping Ouyang

Uranium dioxide (UO2) is the typical fuel that is used in nuclear fission reactor, fission gas are produced during and after the reactor operation, and the fission gas have a significant impact on the performance of UO2 in reactor. In this paper, we investigated the effects of the fission gas on the performance of UO2 by using the first-principles calculation method based on the density functional theory. The results are that, the volume of UO2 increased when there is a fission gas atom enter in UO2 supercell; fission gas prefer to occupy the octahedral interstitial site over the uranium vacancy site and the oxygen vacancy site, and the oxygen vacancy site is the most difficult occupied site due to the formation of an oxygen vacancy is more difficult than that of the uranium vacancy; our results of the UO2 elastic constants are in good agreement with other simulation results and experimental data, and the fission gas atoms make the ductility of UO2 decreased. Our works may shed some light on the development of the UO2 fuel and the spent fuel reprocessing.


2014 ◽  
Vol 26 (25) ◽  
pp. 255503
Author(s):  
Tran Phan Thuy Linh ◽  
Mamoru Sakaue ◽  
Susan Meñez Aspera ◽  
Musa Alaydrus ◽  
Triati Dewi Kencana Wungu ◽  
...  

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