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- Oleshkevych, Anna, et al.
(author)
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Thermally driven redistribution of phases and components in Cu/Sn thin films
- 2012
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In: Journal of Alloys and Compounds. - : Elsevier BV. - 0925-8388 .- 1873-4669. ; 535, s. 108-113
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Journal article (peer-reviewed)abstract
- Unusual features of phase transformations under the thermal treatment of the thin films system Cu (80 nm)-Sn (20 nm) have been studied using a range of physical methods. Processes of mass transfer in thin layers were studied and regimes of thermal treatment were chosen to compare the influence of different temperatures for a given time and the influence of annealing time at a fixed temperature. Presence of the intermetallic phase Cu6Sn5 in the as-deposited state and its transformation into Cu3Sn phase after annealing at temperature 373 K for different times has been identified by grazing incidence X-ray diffraction. Annealing at a temperature of 473 K, and higher, leads to the formation, unexpectedly, of the Cu4Sn phase. The concentration distribution of tin through the depth of the sample was obtained by Rutherford backscattering spectroscopy and demonstrated the existence of the Cu4Sn composition. The topography of the surface of the samples was determined with atomic-force microscopy.
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| 2. |
- Pálsson, Gunnar K., et al.
(author)
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Using light transmission to watch hydrogen diffuse
- 2012
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In: Nature Communications. - : Springer Science and Business Media LLC. - 2041-1723. ; 3, s. 892-
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Journal article (peer-reviewed)abstract
- Because of its light weight and small size, hydrogen exhibits one of the fastest diffusion rates in solid materials, comparable to the diffusion rate of liquid water molecules at room temperature. The diffusion rate is determined by an intricate combination of quantum effects and dynamic interplay with the displacement of host atoms that is still only partially understood. Here we present direct observations of the spatial and temporal changes in the diffusion-induced concentration profiles in a vanadium single crystal and we show that the results represent the experimental counterpart of the full time and spatial solution of Fick's diffusion equation. We validate the approach by determining the diffusion rate of hydrogen in a single crystal vanadium (001) film, with net diffusion in the [110] direction.
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