Proton hopping conductivity in quasi-one-dimensional hydrogen-bonded chains

We study the frequency- and temperature-dependent protonic hopping conducti vity sigma(omega, T) in hydrogen-bonded chains on the basis of a two-stage transport model where the interactions with optical phonon stretching modes are taken into account. The analytical calculations performed using the Ku bo theory reveal the two-step character of the proton delocalization in the chains on heating. It is also shown that the specific Grotthuss transport mechanism manifests itself in the appearance of two distinct peaks in the f requency dependences of sigma and the heights of these maxima depend strong ly on the proton-phonon coupling strengths.