ELECTRON-PHONON COUPLING IN PDHX AND PDDX FILMS

We present measurements on the normal state resistivity and on the superconducting tunneling conductance in order to investigate the electron-phonon coupling in PdHx, (D). We observe that the electrons couple mainly to the optical phonons and that this interaction increases strongly with the D (or H) concentration x. The coupling to acoustic phonons is weaker and nearly concentration independent. Deviations from the harmonic approximation are also reported which explains the inverse isotope effect observed for the superconducting transition temperatures. © by Akademische Verlagsgesellschaft