Study of ionic conductors by X-ray and neutron diffraction

Thermally excited ions can move through the crystal lattice in fast ionic conductors. Therefore the potential has to be shallow along the diffusion path of these mobile ions. Their thermal vibrations are characterized by large amplitudes, at least in the directions of their diffusion paths. Diffraction experiments allow an exact determination of the thermal vibrational amplitudes and thereby the determination of an effective atomic potential. These potentials can be used to construct the potential along the diffusion path of the mobile ions and to estimate their activation energy. This is shown for the Li conductor Li3N and the high temperature phases of the Ag conductors AgI, Ag3SI and Ag2S. (Auth.)