NOVEL FORMS OF HYDROGEN IN SOLIDS - THE IONIC PROTON AND THE QUASI-FREE PROTON

Recent incoherent inelastic neutron scattering studies (IINS) of proto n conductors are reviewed. These studies illustrate the utility of IIN S for studying the structure and the conductivity mechanism of protoni c species and for obtaining a coherent description of the dynamics of H-containing materials. Special attention is given to the understandin g of the quasi-continuum observed in many protonic materials. Emphasis is given to un-solvated, or poorly solvated, proton systems which rem ain stable in the medium to high temperature range (100-500 degrees C) (beta-alumina, 12-tungstophosphoric acids (WPA), MnO2, polyanilines).