Low-Temperature Superionic Conductivity in Strained Yttria-Stabilized Zirconia

Very high lateral ionic conductivities in epitaxial cubic yttria-stabilized zirconia (YSZ) synthesized on single-crystal SrTiO3and MgO substrates by reactive direct current magnetron sputtering are reported. Superionic conductivities (i.e., ionic conductivities of the order similar to 1 Omega(-1)cm(-1)) are observed at 500 degrees C for 58-nm-thick films on MgO. The results indicate a superposition of two parallel contributions - one due to bulk conductivity and one attributable to conduction along the film substrate interface. Interfacial effects dominate the conductivity at low temperatures (andlt;350 degrees C), showing more than three orders of magnitude enhancement compared to bulk YSZ. At higher temperatures, a more bulk-like conductivity is observed. The films have a negligible grain-boundary network, thus ruling out grain boundaries as a pathway for ionic conduction. The observed enhancement in lateral ionic conductivity is caused by a combination of misfit dislocation density and elastic strain in the interface. These very high ionic conductivities in the temperature range 150-500 degrees C are of great fundamental importance but may also be technologically relevant for low-temperature applications.Original Publication:Michael Sillassen, Per Eklund, Nini Pryds, Erik Johnson, Ulf Helmersson and Jorgen Bottiger, Low-Temperature Superionic Conductivity in Strained Yttria-Stabilized Zirconia, 2010, ADVANCED FUNCTIONAL MATERIALS, (20), 13, 2071-2076.http://dx.doi.org/10.1002/adfm.201000071Copyright: John Wiley & Sons, Ltdhttp://eu.wiley.com/WileyCDA/Brand/id-35.htm