Low-temperature superionic conductivity in strained yttria-stabilized zirconia

TY - JOUR

T1 - Low-temperature superionic conductivity in strained yttria-stabilized zirconia

AU - Sillassen, Michael

AU - Eklund, Per

AU - Pryds, Nini

AU - Johnson, Erik

AU - Helmersson, Ulf

AU - Bøttiger, Jørgen

PY - 2010/7/9

Y1 - 2010/7/9

N2 - Very high lateral ionic conductivities in epitaxial cubic yttria-stabilized zirconia (YSZ) synthesized on single-crystal SrTiO 3 and MgO substrates by reactive direct current magnetron sputtering are reported. Superionic conductivities (i.e., ionic conductivities of the order ∼1 Omega; -1cm -1) are observed at 500 °C for 58-nm-thick films on MgO. The results indicate a superposition oftwo 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 (<350 °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 grainboundary 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 °C are of great fundamental importance but may also be technologically relevant for low-temperature applications.

AB - Very high lateral ionic conductivities in epitaxial cubic yttria-stabilized zirconia (YSZ) synthesized on single-crystal SrTiO 3 and MgO substrates by reactive direct current magnetron sputtering are reported. Superionic conductivities (i.e., ionic conductivities of the order ∼1 Omega; -1cm -1) are observed at 500 °C for 58-nm-thick films on MgO. The results indicate a superposition oftwo 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 (<350 °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 grainboundary 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 °C are of great fundamental importance but may also be technologically relevant for low-temperature applications.

U2 - 10.1002/adfm.201000071

DO - 10.1002/adfm.201000071

M3 - Journal article

SN - 1616-301X

VL - 20

SP - 2071

EP - 2076

JO - Advanced Functional Materials

JF - Advanced Functional Materials

IS - 13

ER -