Flash in argon atmosphere yields electronically conducting yttria-stabilized zirconia at ambient temperature

This is the second report on the retention of electronic conductivity in yttria-stabilized zirconia at room temperature after cooling down from the state of flash. In the first report, the specimens (which were flashed in air) were quenched by in-flash immersion into liquid nitrogen. Now we show that if the specimens are flashed in Ar in a glove box (O₂ < 1 ppm), then they remain electronic conductors under nominal cooling. Indeed, the conductivity of the Ar-flashed specimens is higher than the conductivity of LN₂-quenched samples. In both instances, their conductivity increases with flash current. In contrast, specimens flashed in air, and then air-cooled, become insulating akin to their original condition. We propose a possible pathway for such a reaction. In addition, we report measurements of the interface resistance at the anode and the cathode by the four-point technique. In air, the resistance at anode is higher than at the cathode, and the sum of the interface resistances is about one half of the total end-to-end resistance.