Ab initio approach to the effect of Fe on the diffusion in hcp Zr II: The energy barriers

• Published in: Journal of nuclear materials Vol. 392; no. 1; pp. 100 - 104
• Main Authors: Pasianot, R.C., Pérez, R.A., Ramunni, V.P., Weissmann, M.
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier B.V 01.07.2009; Elsevier
• Subjects: Applied sciences; Controled nuclear fusion plants; Energy; Energy. Thermal use of fuels; Exact sciences and technology; Fission nuclear power plants; Fuels; Installations for energy generation and conversion: thermal and electrical energy; Nuclear fuels; 66.30.−h; 66.10.cg; 66.30.−J; 82.20.Wt; Impurity; Iron; Diffusion coefficient; Diffusion; Algorithm; Computing method; Nuclear reactor
• ISSN: 0022-3115; 1873-4820
• DOI: 10.1016/j.jnucmat.2009.03.051

Using density functional theory calculations together with the Monomer method for the search of saddle points (combined for the first time with an ab initio algorithm), we obtain the vacancy formation energies and the migration barriers for α-Zr self-diffusion and for the diffusion of interstitial impurities, including the ultra-fast diffuser Fe. Good agreement with measured diffusion coefficients is obtained, as a much lower energy barrier for the ultra-fast diffuser is found. We also suggest a possible mechanism for the increase in self-diffusion due to the Fe impurity, always present in the experimental samples.