Novel forms of hydrogen in solids: the `ionic' proton and the `quasi-free' proton
Abstract Recent incoherent inelastic neutron scattering studies (IINS) of proton conductors are reviewed. These studies illustrate the utility of IINS for studying the structure and the conductivity mechanism of protonic species and for obtaining a coherent description of the dynamics of H-containing materials. Special attention is given to the understanding of the quasi-continuum observed in many protonic materials. Emphasis is given to un-solvated, or poorly solvated, proton systems which remain stable in the medium to high temperature range (100–500°C) ( β -alumina, 12-tungstophosphoric acids (WPA), MnO 2 , polyanilines).