Abstract
The diffusion of hydrogen in MgB2 is crucial to the kinetics of rehydrogenation of Mg(BH4)2. We report a comprehensive combination of first-principles calculations and Kinetic Monte Carlo Simulations to examine the energetics of diffusion of hydrogen atoms through bulk MgB2. From these calculations we find that diffusion is fast for the neutral interstitial hydrogen defect and that the overall migration barrier for hydrogen diffusion in MgB2 is 0.22 eV, showing that rapid diffusion of hydrogen is possible even at moderate temperatures. The interstitial hydrogen defect formation energy is around 0.8 eV at 0 K, indicating a low hydrogen solubility at moderate temperatures.
Original language | English (US) |
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Pages (from-to) | 86-91 |
Number of pages | 6 |
Journal | Scripta Materialia |
Volume | 117 |
DOIs | |
State | Published - May 1 2016 |
Funding
Y.W. and C.W. gratefully acknowledge financial support from the US Department of Energy under Grant No. DE-FC36-08GO18136 . K.M. gratefully acknowledges financial support from the US DOE under grant No. DE-FG02-07ER46433 . This research used resources of the National Energy Research Scientific Computing Center, which is supported by the Office of Science of the U.S. Department of Energy under Contract No. DE-AC02-05CH11231 .
Keywords
- Atomic diffusion
- Hydrogen storage
- Mg(BH) kinetics
ASJC Scopus subject areas
- General Materials Science
- Condensed Matter Physics
- Mechanics of Materials
- Mechanical Engineering
- Metals and Alloys