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First-principles st...
First-principles study of hydrogen diffusion in α-Al 2O3 and liquid alumina
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- Belonoshko, Anatoly B. (författare)
- KTH,Fysik
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- Rosengren, Anders (författare)
- KTH,Fysik
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- Dong, Qian (författare)
- KTH,Materialvetenskap
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- Hultquist, Gunnar (författare)
- KTH,Materialvetenskap
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- Leygraf, Christofer (författare)
- KTH,Materialvetenskap
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(creator_code:org_t)
- 2004
- 2004
- Engelska.
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Ingår i: Physical Review B Condensed Matter. - 0163-1829 .- 1095-3795. ; 69:2, s. 243021-243026
- Relaterad länk:
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https://urn.kb.se/re...
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https://doi.org/10.1...
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Abstract
Ämnesord
Stäng
- We have studied the energetics and mobility of neutral hydrogen in alumina Al2O3 using ab initio density-functional calculations. The mobility of hydrogen was studied in corundum (α-Al2O 3) as well as in liquid alumina. Using both static as well as molecular-dynamics calculations, and applying classical transition state theory, we derive the temperature-dependent diffusivity of hydrogen in α-Al 2O3 as D(T)=(21.7 × 10-8 m 2/s)exp(-1.24 eV/kT). The corresponding diffusivity of hydrogen in liquid/amorphous alumina, derived directly from ab initio molecular dynamics calculations, is D(T)=(8.71 × 10-7 m2/s)exp(-0.91 eV/kT). The computed diffusivity compares very well to experimental data. We conclude that diffusion of neutral hydrogen through the bulk of alumina is a good approximation of the mechanism for hydrogen mobility in corrosion scales. The representation of grain-boundary structures by amorphous alumina is, probably, realistic at higher temperatures.
Ämnesord
- TEKNIK OCH TEKNOLOGIER -- Kemiteknik -- Korrosionsteknik (hsv//swe)
- ENGINEERING AND TECHNOLOGY -- Chemical Engineering -- Corrosion Engineering (hsv//eng)
Nyckelord
- aluminum oxide
- hydrogen
- ab initio calculation
- article
- corrosion
- density functional theory
- diffusion
- energy transfer
- molecular dynamics
- temperature dependence
Publikations- och innehållstyp
- ref (ämneskategori)
- art (ämneskategori)
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