Visualization of hydrogen migration in solids using switchable mirrors

Autor: RM Jungblut, S. J. van der Molen, M. Kremers, F.J.A. den Broeder, W. H. Huisman, Bernard Dam, P. A. Duine, R. M. N. Hanzen, A.T.M. van Gogh, M. Haaksma, R.P. Griessen, J.H. Rector, J. N. Huiberts, D.G. Nagengast, N.J. Koeman, S. Plota
Přispěvatelé: Photo Conversion Materials, Physics and Astronomy, Student Lab and Education
Rok vydání: 1998
Předmět:
Zdroj: Nature, 394, 656-658. Nature Publishing Group
den Broeder, F J A, van der Molen, S J, Kremers, M, Huiberts, J N, Nagengast, D G, van Gogh, A T M, Huisman, W H, Koeman, N J, Dam, B, Rector, J H, Plota, S, Haaksma, M, Hanzen, R M N, Jungblut, R M, Dunie, P A & Griessen, R P 1998, ' Visualization of hydrogen migration in solids using switchable mirrors. ', Nature, vol. 394, pp. 656-658 . https://doi.org/10.1038/29250
ISSN: 1476-4687
0028-0836
DOI: 10.1038/29250
Popis: Switchable mirrors1,2,3 made of thin films of the hydrides of yttrium (YHx), lanthanum (LaHx) or rare-earth metals exhibit spectacular changes in their optical properties as x is varied from 0 to 3. For example, α-YHx 2.85 is a yellowish transparent semiconductor. Here we show that this concentration dependence of the optical properties, coupled with the high mobility of hydrogen in metals, offers the possibility of real-time visual observation of hydrogen migration in solids. We explore changes in the optical properties of yttrium films in which hydrogen diffuses laterally owing to a large concentration gradient. The optical transmission profiles along the length of the film vary in such a way as to show that the formation of the various hydride phases is diffusion-controlled. We can also induce electromigration of hydrogen, which diffuses towards the anode when a current flows through the film. Consequently, hydrogen in insulating YH3−δ behaves as a negative ion, in agreement with recent strong-electron-correlation theories4,5. This ability to manipulate the hydrogen distribution (and thus the optical properties) electrically might be useful for practical applications of these switchable mirrors.
Databáze: OpenAIRE
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