Dynamical Aspects of Nanocrystalline Ion Conductors Studied by NMR

In recent years, nanocrystalline materials have considerably attracted the interest of the materials research community [1–4]. Single-phase materials with an average particle diameter of less than 50 nm exhibit new or at least enhanced chemical and physical properties when compared to their coarse-grained counterparts. For example, they show new mechanical [5–8], electrical [9–13], magnetic [14–19], optical [20–24], catalytic [25, 26], and/or thermodynamic [27–29] features. In ion conducting nanocrystalline materials, an enhancement of the diffusivity of small cations and anions like Li⁺ and F⁻, or even larger anions like O²⁻, is often observed [2–4, 30–41]. The diffusivity is additionally influenced by admixing an ionic insulator to the conducting phase [4, 42–47].