PROBIEN   20416
INSTITUTO DE INVESTIGACION Y DESARROLLO EN INGENIERIA DE PROCESOS, BIOTECNOLOGIA Y ENERGIAS ALTERNATIVAS
Unidad Ejecutora - UE
artículos
Título:
Hydrogen absorption in Pd thin films
Autor/es:
RAMOS DE DEBIAGGI S.; CRESPO E.A.; BRASCHI F.; BRINGA E.; ALÍ M.L.; RUDA M.
Revista:
INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
Editorial:
PERGAMON-ELSEVIER SCIENCE LTD
Referencias:
Lugar: Amsterdam; Año: 2014 vol. 39 p. 8590 - 8595
ISSN:
0360-3199
Resumen:
Hydrogen absorption isotherms for
Pd thin films were modeled at atomistic scale by Monte Carlo (MC) simulation in the TPmN ensamble and by Molecular
Dynamics (MD) simulations at 300 K. The interaction among atoms was modeled by
embedded atom method (EAM) potentials. Simulated samples consisted of monocrystalline
nanofilms with different thickness (2-8 nm) and two crystallographic surface
orientations, (001) and (111). The isotherms were compared to bulk Pd and a few
available experimental results. Instead of the plateau corresponding to the a-b
PdH equilibrium in the bulk, the isotherms at nanofilms show a two-plateaux
behavior: a small one corresponding to a surface-subsurface hydride formation,
and a larger one for the subsequent bulk hydride formation. This is strongly
correlated with the atomic stress distribution induced within the thin film.
The equilibrium pressures at the isotherms depend on the thin-film thickness,
with pressure being larger for thicker films. The
isotherms of the (001) films display lower equilibriumpressures than those for (111) films.