Ab Initio Study of Defect Properties in YPO4

Journal Article · Thu Mar 01 04:00:00 EST 2012 · Computational Materials Science

DOI:https://doi.org/10.1016/j.commatsci.2011.10.005· OSTI ID:1033824

Gao, Fei; Xiao, Haiyan Y; Zhou, Yungang; Devanathan, Ramaswami; Hu, Shenyang Y; Li, Yulan; Sun, Xin; Khaleel, Mohammad A

Ab initio methods based on density functional theory have been used to calculate the formation energies of intrinsic defects, including vacancies, interstitials, antisites and Frenkel pairs in YPO4 under the O-rich and Y2O3-rich, and the O-rich and Y-rich conditions. The larger size of the yttrium atom may give rise to higher formation energy of the phosphorus antisite defect. In general, the formation energies of anion interstitials are much smaller than those of cation interstitials for both conditions considered. It is of greatly interest to find that the relative stabilities among the same types of interstitials are independent of the reference states. The most stable configuration for oxygen interstitials is an O-O split interstitial near the Ta site, while the most stable configuration for cation interstitials is a tetrahedral interstitial near the Ta site. The cation split interstitials are unfavorable in YPO4, with much higher formation energies. Furthermore, the properties of Frenkel pairs are compared with those calculated using empirical potentials. The results reveal that both ab initio and empirical potential calculations show a similar trend in the formation energies of Frenkel pairs, but the formation energies obtained by empirical potentials are much larger than those calculated by ab initio method.

• Research Organization: Pacific Northwest National Laboratory (PNNL), Richland, WA (US)
• Sponsoring Organization: USDOE
• DOE Contract Number: AC05-76RL01830
• OSTI ID: 1033824
• Report Number(s): PNNL-SA-83433; AF5831060
• Journal Information: Computational Materials Science, Journal Name: Computational Materials Science Vol. 54
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
ANIONS
ATOMS
Ab initio calculations
CATIONS
CONFIGURATION
DEFECTS
Defect formation
Defect stability
FUNCTIONALS
INTERSTITIALS
Interatomic potential calculations
OXYGEN
PHOSPHORUS
VACANCIES
YPO4
YTTRIUM