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dc.contributor.authorLin, Jian
Ji, Heng
Swift, Michael W.
Hardy, Will J.
Peng, Zhiwei
Fan, Xiujun
Nevidomskyy, Andriy H.
Tour, James M.
Natelson, Douglas
dc.date.accessioned 2016-06-27T14:14:27Z
dc.date.available 2016-06-27T14:14:27Z
dc.date.issued 2014
dc.identifier.citation Lin, Jian, Ji, Heng, Swift, Michael W., et al.. "Hydrogen Diffusion and Stabilization in Single-Crystal VO2 Micro/Nanobeams by Direct Atomic Hydrogenation." Nano Letters, 14, no. 9 (2014) American Chemical Society: 5445-5451. http://dx.doi.org/10.1021/nl5030694.
dc.identifier.urihttps://hdl.handle.net/1911/90571
dc.description.abstract We report measurements of the diffusion of atomic hydrogen in single crystalline VO2 micro/nanobeams by direct exposure to atomic hydrogen, without catalyst. The atomic hydrogen is generated by a hot filament, and the doping process takes place at moderate temperature (373 K). Undoped VO2 has a metal-to-insulator phase transition at ∼340 K between a high-temperature, rutile, metallic phase and a low-temperature, monoclinic, insulating phase with a resistance exhibiting a semiconductor-like temperature dependence. Atomic hydrogenation results in stabilization of the metallic phase of VO2 micro/nanobeams down to 2 K, the lowest point we could reach in our measurement setup. Optical characterization shows that hydrogen atoms prefer to diffuse along the c axis of rutile (a axis of monoclinic) VO2, along the oxygen “channels”. Based on observing the movement of the hydrogen diffusion front in single crystalline VO2 beams, we estimate the diffusion constant for hydrogen along the c axis of the rutile phase to be 6.7 × 10–10 cm2/s at approximately 373 K, exceeding the value in isostructural TiO2 by ∼38×. Moreover, we find that the diffusion constant along the c axis of the rutile phase exceeds that along the equivalent a axis of the monoclinic phase by at least 3 orders of magnitude. This remarkable change in kinetics must originate from the distortion of the “channels” when the unit cell doubles along this direction upon cooling into the monoclinic structure. Ab initio calculation results are in good agreement with the experimental trends in the relative kinetics of the two phases. This raises the possibility of a switchable membrane for hydrogen transport.
dc.language.iso eng
dc.publisher American Chemical Society
dc.rights This is an author's peer-reviewed final manuscript, as accepted by the publisher. The published article is copyrighted by the American Chemical Society.
dc.title Hydrogen Diffusion and Stabilization in Single-Crystal VO2 Micro/Nanobeams by Direct Atomic Hydrogenation
dc.type Journal article
dc.citation.journalTitle Nano Letters
dc.contributor.org Smalley Institute for Nanoscale Science and Technology
dc.subject.keywordVO2
atomic hydrogenation
hydrogen diffusion
MIT
dc.citation.volumeNumber 14
dc.citation.issueNumber 9
dc.type.dcmi Text
dc.identifier.doihttp://dx.doi.org/10.1021/nl5030694
dc.identifier.pmid 25148601
dc.type.publication post-print
dc.citation.firstpage 5445
dc.citation.lastpage 5451


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