In situx-ray diffraction topography studies on the phase formation in thin yttrium hydride films
| Autor: | A. Remhof, G. Song, C. Sutter, D. Labergerie, M. Hübener, H. Zabel, J. Härtwig |
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| Přispěvatelé: | Photo Conversion Materials |
| Rok vydání: | 2000 |
| Předmět: | |
| Zdroj: | Physical Review B. Condensed Matter and Materials Physics, 62, 2164-2172. American Physical Society Remhof, A, Song, G, Sutter, C, Labergerie, D, Zabel, H & Haertwig, J 2000, ' In situ x-ray diffraction topography studies on the phase formation in thin yttrium hydride ', Physical Review B. Condensed Matter and Materials Physics, vol. 62, pp. 2164-2172 . https://doi.org/10.1103/PhysRevB.62.2164 |
| ISSN: | 1095-3795 0163-1829 1098-0121 |
| DOI: | 10.1103/physrevb.62.2164 |
| Popis: | Structural phase transitions in thin, epitaxial yttrium hydride films have been studied by means of synchrotron x-ray diffraction topography ~XDT!, complemented by atomic force microscopy and by measurements of the electrical resistance. Depending on the applied hydrogen pressure during the gas-phase loading experiments and the chosen temperature, different phases exhibiting different symmetries and electronic properties could be established. Despite the small scattering volume of the 200-nm-thick film, the phase nucleation, the spatial distribution of domains as well as the lateral hydrogen diffusion could be observed. Those experiments demonstrate the feasibility of XDT to study structural properties like the dynamics of phase transitions in thin epitaxially grown films on the nanometer scale. From the progression of the domain boundary between the YH2 and YH3 phase the hydrogen mobility was determined to 5310 26 cm 2 /s at 300 °C. Comparing hightemperature topographies with room-temperature results confirms that the phase boundary is narrower at high temperatures. Finally resistance measurements of Y/Nb double layers with varying hydrogen concentration confirm clearly that the YH 3 phase is insulating and that the resistance of the yttrium layer increases proportionally to the degree of YH3 phase precipitation. The layer system acts as a hydrogen concentration-dependent potentiometer and could be used as a hydrogen sensor. |
| Databáze: | OpenAIRE |
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