Diffusion coefficient of H in Fe: first principles calculation

Author(s): P. de Andres, J. Sanchez, A. Ridruejo
Paper category: Proceedings
Book title: Proceedings of the International Conference on Sustainable Materials Systems and Structures (SMSS2019) Durability, Monitoring and Repair of Structures
Editor(s): Ana Baričević, Marija Jelčić Rukavina, Domagoj Damjanović, Maurizio Guadagnini
ISBN: 978-2-35158-217-6
e-ISBN: 978-2-35158-218-3
Publisher: RILEM Publications SARL
Publication year: 2019
Pages: 292-299
Total Pages: 813
Language: English

Abstract: First principles density functional theory was used to calculate the phonon spectrum of a bcc iron lattice with interstitial hydrogen to find the vibrational contribution to the Helmholtz free energy, F. Clear differences between high (Fe:H=1:1) and low (Fe:H=16:1) concentration conditions were observed, particularly in connection with the proportion of H occupancy of octahedral and tetrahedral sites in the lattice. The variation in the diffusion coefficient with temperature was estimated by applying a simple mixing rule to these populations and factoring in the temperature-dependence of F. This prediction proved to be in good agreement with experimental results reported by McLellan (Acta Metal. 31, 961).

Online publication :2019
Publication type : full_text
Public price (Euros) : 00