Figure 6. Evidence of a conduction gradient.

(a) Time dependence of conductance measured between adjacent pairs of voltage pick-off electrodes (denoted in the legend), with a constant current of 5E-5 amps flowing between electrodes 1 and 7 (see Fig. 1 for electrode configuration). Measurements were taken at 370 °C, with the sample equilibrated at pO₂=1.5 torr. (b) Conductance as a function of position on the sample, at steady state. The conductance is largest near the negative current electrode and shows a gradient across the sample.