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The Particle-Size Dependence of the Activation Energy for Decomposition of Lithium Amide


  • K.H. was supported by General Motors Corporation, and A.J. by the U. S. Department of Energy (grant no. DE-FG02-07ER46434). We acknowledge use of the CNSI Computing Facility under NSF grant no. CHE-0321368 and NERSC resources supported by the DOE Office of Science under contract no. DE-AC02-05CH11231.


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A question of size: LiNH2 decomposes into Li2NH and NH3 through two competing mechanisms, one that involves the formation of native defects in the interior of the material (by a Frenkel pair mechanism) and the other at the surface (see picture; H red, Li gray, N blue). The prevailing mechanism and hence the activation energy thus depend on the surface-to-volume ratio, or the specific surface area, which changes with the particle size.