Rapid Li Ion Dynamics in the Interfacial Regions of Nanocrystalline Solids.

摘要: Diffusive processes are ubiquitous in nature. In solid state physics, metallurgy and materials science the diffusivity of ions govern functionality many devices such as sensors or batteries. Motional on surfaces, across interfaces through membranes can be quite different to that bulk. A direct, quantitative description local diffusion is, however, rare. Here, we took advantage 7Li longitudinal nuclear magnetic relaxation study, atomic length scale, diffusive motion lithium spins interfacial regions nanocrystalline, orthorhombic LiBH4. Magnetization transients free induction decays revealed a fast subset Li having access surface pathways offer activation barriers (0.18 eV) much lower than those crystalline bulk (0.55 eV). These observations make borohydride new nanostructured model system study disorder-induced enhancements processes.