Molecular dynamics study of self-diffusion in Zr

Abstract

We employed a recently developed semi-empirical Zr potential to determine the diffusivities in hcp and bcc Zr via molecular dynamics simulation. The point defect concentration was determined directly from molecular dynamics (MD) simulation rather than from theoretical methods using T = 0 calculations. Our MD simulation indicates that the diffusion proceeds via the interstitial mechanism in hcp Zr, and both vacancy and interstitial mechanisms contribute to diffusivity in bcc Zr. The agreement with the experimental data is excellent for hcp Zr and rather good for bcc Zr at high temperatures, but there is considerable disagreement at low temperatures.

Keywords:

• molecular dynamics simulations
• point defects
• diffusion
• zirconium

Acknowledgements

Work at the Ames Laboratory was supported by the Department of Energy, Office of Basic Energy Sciences, under Contract No. DE-AC02-07CH11358. Work at MISIS was supported by the Ministry of Education under the contract No. 02.513.11.3402 and by RFBR under grant No. 08.03.00498. MIM gratefully acknowledge useful discussions with Dr. R.T. Ott.