Principles of Main Experimental Methods
Ionic conductors may act as transducers for a large variety of fundamental thermodynamic and kinetic quantities. The application of a voltmeter even with very high input impedance requires a small current. A chemical reaction will occur in the galvanic cell by the transfer of the ions. The determination of phase equilibria is based on coulometric titration which was originally developed for the variation of the stoichiometry of binary compounds. The chemical diffusion coefficient describes the relaxation of compositional gradients to achieve a homogeneous composition. The electronic conductivity of good electronic conductors is often sufficiently close to the total conductivity. The starting stoichiometry is known from the preparation or may be established from the shape of the coulometric titration curve, which exhibits an inflection point for small concentrations of defects. Electrochemical methods may also be used to investigate the transport of species across interfaces.