REVIEW OF THE LIMITATION OF THE HEBB-WAGNER POLARIZATION METHOD FOR MEASURING PARTIAL CONDUCTIVITIES IN MIXED IONIC ELECTRONIC CONDUCTORS

The limitation of the use of partial current blocking for determining partial conductivities in mixed ionic electronic conductors, MIECs, is reviewed. The discussion refers to the Hebb-Wagner polarization metho d for determining the electronic conductivity and to its analogue for determining the ionic conductivity. These two methods suffer from seve re problems that may render results useless because of false interpret ation. The problems are discussed. New experimental evidence for some problems is presented. A four point, Hebb-Wagner type, measurement is discussed. It allows one to detect whether the correct experimental co nditions prevail.