Hydrogen tracer diffusion in LiBH4 measured by spatially resolved Raman spectroscopy.
The hydrogen tracer diffusion in LiBH(4) has been determined by spatially resolved Raman spectroscopy. The measurements give direct evidence of a macroscopic diffusion of BH ions as well as atomic exchange of hydrogen between the anions. An effective tracer diffusion coefficient of deuterium in LiBH(4) of D approximately 7 x 10(-14) m(2) s(-1) at 473 K is derived. The direct exchange rate of hydrogen between BH(4) units is 10 orders of magnitude slower, i.e. the relatively fast effective hydrogen diffusion has its origin in the fast diffusion of BH(4) units.
Borgschulte
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Empa, Swiss Federal Laboratories for Materials Testing and Research, Laboratory 138, Hydrogen & Energy, Uberlandstrasse 129, CH-8600 Dübendorf, Switzerland. andreas.borgschulte@empa.ch
Gremaud
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Łodziana
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Züttel
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