TY - JOUR
T1 - Energetics and diffusional properties of He in BCC Mo
T2 - An empirical potential for molecular dynamics simulations
AU - Zhang, Yongfeng
AU - Millett, Paul C.
AU - Tonks, Michael
N1 - Funding Information:
The authors gratefully acknowledge the support of the LDRD project at Idaho National Lab. (INL) on “Irradiation-induced evolution of defect and microstructure in nanocrystalline BCC Mo” (INL-LDRD 10-008-CP.01.01.GL.08.11). The authors also thank Dr. Bulent Biner for beneficial discussions and comments on the manuscript. Yongfeng Zhang thanks Mr. Ernst Schumacher for sharing the code fdalin ( www.chemsoft.com ) on calculation of electron density distribution.
PY - 2011/10
Y1 - 2011/10
N2 - This paper presents an interatomic potential for modeling He defects and bubbles in body-centered-cubic (BCC) Mo. We utilize three existing frameworks: the Finnis-Sinclair (FS) potential for Mo-Mo, the Effective-Medium-Theory (EMT) for He-Mo, and the Hartree-Fock-Dispersion (HFD) potential for He-He interactions. The energetics of He defects and the diffusivity of He interstitial given by this potential agree well with ab initio calculations and experimental measurements. Furthermore, in agreement with theoretical prediction, it is shown that the introduction of He gas suppresses the surface diffusivity of BCC Mo, which decays exponentially with increasing He pressure acting on the free surface. The decay constant, correlated with the characteristic interaction volume for He-Mo, is close to the atomic volume of BCC Mo. This suppression effect is important to understand the mobility of small He bubbles.
AB - This paper presents an interatomic potential for modeling He defects and bubbles in body-centered-cubic (BCC) Mo. We utilize three existing frameworks: the Finnis-Sinclair (FS) potential for Mo-Mo, the Effective-Medium-Theory (EMT) for He-Mo, and the Hartree-Fock-Dispersion (HFD) potential for He-He interactions. The energetics of He defects and the diffusivity of He interstitial given by this potential agree well with ab initio calculations and experimental measurements. Furthermore, in agreement with theoretical prediction, it is shown that the introduction of He gas suppresses the surface diffusivity of BCC Mo, which decays exponentially with increasing He pressure acting on the free surface. The decay constant, correlated with the characteristic interaction volume for He-Mo, is close to the atomic volume of BCC Mo. This suppression effect is important to understand the mobility of small He bubbles.
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U2 - 10.1016/j.commatsci.2011.06.005
DO - 10.1016/j.commatsci.2011.06.005
M3 - Article
AN - SCOPUS:79960342854
SN - 0927-0256
VL - 50
SP - 3224
EP - 3229
JO - Computational Materials Science
JF - Computational Materials Science
IS - 11
ER -