Activatino of Erbium Films for Hydrogen Storage
Hydriding of metals can be routinely performed at high temperature in a rich hydrogen atmosphere. Prior to the hydrogen loading process, a thermal activation procedure is required to promote facile hydrogen sorption into the metal. Despite the wide spread utilization of this activation procedure, little is known about the chemical and electronic changes that occur during activation and how this thermal pretreatment leads to increased rates of hydrogen uptake. This study utilized variable kinetic energy X-ray photoelectron spectroscopy to interrogate the changes during in situ thermal annealing of erbium films, with results confirmed by time-of-flight secondary ion mass spectrometry and low energy ion scattering. Activation can be identified by a large increase in photoemission between the valence band edge and the Fermi level and appears to occur over a two stage process. The first stage involves desorption of contaminants and recrystallization of the oxide, initially impeding hydrogen loading. Further heating overcomes the first stage and leads to degradation of the passive surface oxide leading to a bulk film more accessible for hydrogen loading.
- Research Organization:
- Brookhaven National Lab. (BNL), Upton, NY (United States)
- Sponsoring Organization:
- USDOE SC OFFICE OF SCIENCE (SC)
- DOE Contract Number:
- DE-AC02-98CH10886
- OSTI ID:
- 1041849
- Report Number(s):
- BNL-97527-2012-JA; JAPIAU; TRN: US201212%%261
- Journal Information:
- Journal of Applied Physics, Vol. 109, Issue 11; ISSN 0021-8979
- Country of Publication:
- United States
- Language:
- English
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Characterization of the surface changes during the activation process of erbium/erbium oxide for hydrogen storage.
Characterization of the surface changes during the activation of erbium/erbium oxide for hydrogen storage.