Ionic motion of silver in super-ionic glasses

We present quasi-elastic neutron scattering data from measurements on super -ionic glasses. The mobile ions give rise to quasi-elastic scattering that can clearly be distinguished from the elastic line. In a high-resolution ex periment we observe motions that can be interpreted in form of a jump diffu sion process, whereas a low-resolution experiment reveals faster processes (0.5 ps) which are probably of a more localised character. The fast compone nt overlaps significantly with the Boson peak, typical for amorphous system s, a fact which has to be taken into account in the analysis. (C) 1999 Else vier Science B.V. All rights reserved.