The fabrication of yttria-stabilized-zirconium/single-wall C nanotube (YSZ/SWCNT) composites was reported. Electrical conductivity measurements from 25 to 800C revealed that the composites exhibited mixed ionic-electronic conduction. At room temperature, the conductivity increased by 11 orders of magnitude with the addition of single-walled C nanotubes to the yttria-stabilized zirconia. At high temperatures (>300C), the ionic conduction of the yttria-stabilized zirconia becomes relevant and a mixed ionic-electronic transport was observed. It was found that the transport could be described by a sum of two parallel contributions: thermally activated ionic conduction from the yttria-stabilized zirconia and fluctuation-assisted tunneling within the single-walled C nanotube network.

Mixed Ionic-Electronic Conductivity in Yttria-Stabilized Zirconia/Carbon Nanotube Composites. F.C.Fonseca, R.Muccillo, D.Z.de Florio, L.O.Ladeira, A.S.Ferlauto: Applied Physics Letters, 2007, 91[24], 243107