Electrochemical interfacial properties of superconductors

The first part of the work explains the ionic conduction processes in RbAg4I5 in the temperature range of 10 K ≤ T ≤ 100 K. The low- and high-frequency performance of polycrystalline RbAg4I5 with various microstructures shows a change in the ionic conduction process at a transfer temperature in the range of 60 K ≤ T ≤ 90 K. At temperatures of T<Tt, the ion transport is observed primarily along the grain boundaries with low activation energies. The second part of the work investigates with a specially developed tripole EIS measuring technique the properties of HTSC/ionic superconductor interfaces as a function of temperature. Through superimposition of an external magnetic field it was possible for the first time to give evidence of the effects of correlated charge carriers in the superconducting phases of HTSC on the observed quantum electrodynamic, kinetic effects at the phase boundary between HTSC and ionic superconductor. The third part explains experiments on pin-pointed application of electrochemical phase boundary reactions for the purpose of local structurisation of surface layers. The tool used is an in-situ scanning probe microscope. In the model system Au(100)/Cu2+ methods have been developed and tested in order to resolve the expected difficulties occurring in the system HTSC/Cu2+. With the process found by the work reported and called ''defect-induced local metal deposition'', it was possible to metallize areas from nanometer size up to the maximum scanning area of the scanning probe microscope. (orig./MM)