RT Journal Article
T1 Direct observation of hydrogen permeation through grain boundaries in tungsten
A1 Diaz Rodriguez, Pablo
A1 Panizo Laiz, Miguel
A1 González Pascual, César
A1 Iglesias, Roberto
A1 Martin Bragado, Ignacio
A1 González Arrabal, Raquel
A1 Perlado, Jose Manuel
A1 Peña Rodríguez, Ovidio
A1 Rivera, Antonio
AB In this paper, we report on an enhanced hydrogen permeation effect along grain boundaries in tungsten. Sputtered nanocolumnar tungsten layers (column lateral dimensions 100–150 nm and layer thickness 2 μm) were analysed by hydrogen permeation measurements in the temperature range 520–705 K. The experiments constitute a direct observation of this effect, previously postulated by means of a combination of indirect experiments and simulations and considered controversial due to the lack of direct measurements. DFT results support this observation since (i) the hydrogen binding energy to the grain boundary is 1.05 eV and (ii) the migration energies along the grain boundary and along the bulk are 0.12 eV and 0.20 eV, respectively. OKMC simulations, parametrized by DFT data, were used as a supporting tool to attain a better understanding of the involved phenomena. The OKMC results are also compatible with the observations. Indeed, they show that the fraction of hydrogen flux along grain boundaries in the steady-state permeation regime increases when decreasing the ratio of lateral dimensions to length of the nanocolumns, rapidly approaching unity when this ratio is < 2. Therefore, grain boundaries act as preferential migration pathways for H atoms at the studied temperature range in the studied samples. This behaviour has interesting implications to reduce the retention of hydrogen in several applications, in particular, fusion materials exposed to plasma discharges.
PB Springer
SN 2522-5731
YR 2022
FD 2022-01-24
LK https://hdl.handle.net/20.500.14352/108067
UL https://hdl.handle.net/20.500.14352/108067
LA eng
NO Díaz-Rodríguez, P., Panizo-Laiz, M., González, C. et al. Direct observation of hydrogen permeation through grain boundaries in tungsten. emergent mater. 5, 1075–1087 (2022).
NO AWP15-ENR-01/CEA-02   (EUROfusion Consortium)QCM-2017-2-0012QCM-2017-3-0009QCM-2019-1-0002QS-2019-2-0002
NO Ministerio de Ciencia e Innovación (España)
NO Comunidad de Madrid
NO Red Española de Supercomputación
DS Docta Complutense
RD 16 dic 2025