Effect of the annealing atmosphere on the layer interdiffusion in Pd/Ti/Pd multilayer stacks deposited on pure Ti and Ti-alloy substrates
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Date
2019
Journal Title
Journal ISSN
Volume Title
Publisher
University of the Western Cape
Abstract
Pd(50 nm)/Ti(25 nm)/Pd(50 nm) multilayer stack has been deposited on Ti and Ti6Al4V substrates; we have studied the intermixing of layers upon annealing at the hydrogenation temperature of 550 °C, under vacuum, H/Ar gas mixture and pure hydrogen atmospheres. Scanning electron microscopy (SEM) micrographs indicated surface roughening in samples annealed under vacuum and H/Ar gas mixture while those annealed under pure H2 remained relatively smoother. Rutherford backscattering spectrometry (RBS) revealed intermixing of layers as evidenced by the diffusion of Pd toward the bulk, while XRD indicated the formation of PdTi2 phase in the samples annealed under vacuum and H/Ar gas mixture atmosphere. In-situ, real-time RBS showed that the annealing under pure H2 preserves the integrity of the Pd catalyst. No indication of the PdTi2 formation in the pure H2 annealed samples was observed; instead only the TiH2 phase appeared, indicating the absorption of H into the system.
Description
Keywords
Palladium-Titanium, Multilayer, Electron beam evaporation, Rutherford backscattering spectrometry, X-ray diffraction
Citation
Magogodi, Steven & Mtshali, C.B. & Halindintwali, Sylvain & Khumalo, Z. & Mongwaketsi, N. & Cloete, Karen & Madito, Moshawe & Pieters, Caswell & Sook, Avesh & Donald, Earl & Cummings, Franscious & Arendse, Christopher. (2019). Effect of the annealing atmosphere on the layer interdiffusion in Pd/Ti/Pd multilayer stacks deposited on pure Ti and Ti- alloy substrates. Nuclear Instruments and Methods in Physics Research Section B Beam Interactions with Materials and Atoms. 461. 37-43. 10.1016/j.nimb.2019.09.018.