AVS 54th International Symposium | |
Applied Surface Science | Tuesday Sessions |
Session AS-TuP |
Session: | Aspects of Applied Surface Science Poster Session |
Presenter: | E.G. Keim, University of Twente. MESA+ Institute, The Netherlands |
Authors: | E.G. Keim, University of Twente. MESA+ Institute, The Netherlands W. Lisowski, Polish Academy of Sciences, Poland M.A. Smithers, University of Twente, MESA+ Institute, The Netherlands Z. Kaszkur, Polish Academy of Sciences, Poland |
Correspondent: | Click to Email |
Thin titanium films can be applied as hydrogen storage material due to titanium hydride (deuteride) formation. However, the morphology of the Ti films, which depends strongly on the Ti film thickness, affects both the deuterium sorption and titanium deuteride decomposition properties.1 Here we present the results of TDMS, XRD, SEM and TEM, showing adsorption-desorption properties of ultra-thin Ti films as well as surface and bulk film morphology changes due to titanium deuteride (TiDy) formation. Ti films, 10-20 nm thick, were prepared in a UHV glass system2 at 300 K. Both volumetrically controlled deuterium adsorption and TDMS3 monitored deuterium evolution was carried out in situ, all other analyses ex situ. It was found that ultra-thin Ti films of fine grained bulk morphology (average grain size about 10 nm) form a TiDy phase with low deuterium content (y ≤ 1.2) after deuterium treatment at 1 Pa pressure. SEM and TEM/XRD analyses reveal a very fine grained (smaller than 8 nm) surface and bulk film morphology. TDMS heating induced decomposition of ultra-thin TiDy films proceeds at low temperature (maximum peak temperature Tm about 500 K) and its kinetics is dominated by a low energy desorption (ED = 0.61 eV) of deuterium from surface and subsurface areas of the Ti film.
1 W. Lisowski, E.G. Keim, Z. Kaszkur, M.A. Smithers, Langmuir, 2007, submitted.
2 W. Lisowski, Vacuum, 54, 13 (1999).
3 W. Lisowski, E.G. Keim and M.A. Smithers, J. Vac. Sci. Technol. A21, 545 (2003).