Paper AS-TuP23
Microstructural Transformations of Ultrathin TiDy/Pd Bi-Layer Films Evaporated on Si(100) and Quartz Induced by Vacuum Annealing

Tuesday, October 21, 2008, 6:30 pm, Room Hall D

Thin TiD_y/Pd bilayer films¹ can be applied as a useful source of deuterium used in chemical and energetic reactions. Evolution of hydrogen from such material is realized by high-temperature annealing. Main question is to what degree structural changes occur within both the substrate and the ultrathin TiD_y/Pd bi-layer film as result of annealing induced decomposition of the titanium deuteride phase. In this paper we present the results of a combined SEM/TEM study dealing with these questions. The results are compared for two ultrathin TiD_y/Pd films evaporated on quartz and Si(100), respectively. Ultrathin TiD_y/Pd films (10 - 20 nm thick TiDy films covered by 10 - 20 nm thick Pd films) were prepared in a UHV glass system.² Decomposition of the titanium deuteride phase in the TiDy/Pd film during annealing, was monitored in situ by TDMS,³ all other analysis ex situ. It was found that annealing of the TiD_y/Pd films, evaporated on various substrates, leads to significant transformations within the films studied. SEM images disclosed various stages of rearrangement of the surface morphology in both films. Energy Filtered TEM analyses of cross-section images as well as EDX point analyses revealed extensive inter-diffusion of Ti and Pd within both Ti-Pd bi-layer films. Moreover, the EF-TEM Si elemental map displayed also a significant penetration of Si atoms from the Si substrate into the Ti area of the Ti-Pd film.

¹ W. Lisowski, E.G. Keim, A.H.J. van den Berg, M.A. Smithers, Anal. Bioanal. Chem. 385 (2006) 700.
² W. Lisowski, Vacuum, 54, 13 (1999).
³ W. Lisowski, E.G. Keim and M.A. Smithers, J. Vac. Sci. Technol. A21, 545 (2003).