Effects of dopant concentration and impurities on the conductivity of magnetron-sputtered nanocrystalline yttria-stabilized zirconia
2010 (English)In: SOLID STATE IONICS, ISSN 0167-2738, Vol. 181, no 19-20, 864-867 p.Article in journal (Refereed) Published
Cubic yttria-stabilized zirconia (YSZ) films with yttria concentrations of 8.7, 9.9, and 11 mol% have been deposited by reactive pulsed DC magnetron from Zr-Y alloy targets. The overall microstructure and texture in the films showed no dependence on the yttria concentration. Films deposited at floating potential had a andlt; 111 andgt; texture. Single-line profile analysis of the 111 X-ray diffraction peak yielded a grain size of similar to 18 nm and a microstrain of similar to 2%. regardless of deposition temperature. Films deposited at 400 degrees C and selected bias voltages in the range from -70 V to -200 V showed a reduced grain size for higher bias voltages, yielding a grain size of similar to 7 nm and a microstrain of similar to 2.5% at a bias voltage of -200 V with additional incorporation of argon. Furthermore, the effect of impurities on the ionic conductivity has been investigated, since Hf impurities were found in the samples with yttria concentrations of 8.7, and 9.9 mol%. Temperature-dependent impedance spectroscopy of the YSZ films, deposited at 400 degrees C and floating potential, showed no variation of the in-plane ionic conductivity with yttria concentration. However, for films deposited at 400 degrees C and a bias -70 V. the in-plane ionic conductivity decreased systematically for samples with yttria concentrations of 8.7 and 9.9 mol% compared to the sample with 11 mol% yttria. This suggests that ionic conduction is not a purely bulk mechanism, but mainly related to the grain boundaries. The activation energy for oxygen ion migration was determined to be between 1.25 and 1.32 eV.
Place, publisher, year, edition, pages
Elsevier Science B.V., Amsterdam. , 2010. Vol. 181, no 19-20, 864-867 p.
YSZ, Physical vapor deposition, X-ray diffraction, Impedance spectroscopy
Engineering and Technology
IdentifiersURN: urn:nbn:se:liu:diva-58636DOI: 10.1016/j.ssi.2010.05.013ISI: 000280542200002OAI: oai:DiVA.org:liu-58636DiVA: diva2:344898
M Sillassen, Per Eklund, N Pryds and J Bottiger, Effects of dopant concentration and impurities on the conductivity of magnetron-sputtered nanocrystalline yttria-stabilized zirconia, 2010, SOLID STATE IONICS, (181), 19-20, 864-867.
Copyright: Elsevier Science B.V., Amsterdam.