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Effect of titania doping and sintering temperature on titanium local environment and electrical conductivity of YSZ

DOI: 10.1016/j.jallcom.2016.07.164 DOI Help

Authors: Maite Colomer (Instituto de CerĂ¡mica y Vidrio) , Clara Guglieri (Elettra Sincrotrone Trieste) , Sofia Diaz-Moreno (Diamond Light Source) , M. Maczka (Institute of Low Temperature and Structure Research, Polish Academy of Sciences) , Roberto Boada Romero (Diamond Light Source) , Jesus Chaboy (Diamond Light Source)
Co-authored by industrial partner: No

Type: Journal Paper
Journal: Journal Of Alloys And Compounds

State: Published (Approved)
Published: July 2016
Diamond Proposal Number(s): 10432

Abstract: The effect that the titania doping and the sintering temperature has on the relationship between the titanium local environment and the electrical properties of YSZ has been studied. To this end, materials obtained for different titania additions ranging from 5 to 30 mol%, and sintered at different temperatures, have been studied. The combined results obtained by XRD, FT-Raman, and FE-SEM-EDX clearly indicate that titania causes the formation of both a titania-doped YSZ solid solution and a titania-doped YTZP solid solution.When the concentration of TiO2 reaches 20 mol% zirconium titanate, that admits Y2O3 in solid solution, crystallizes. In addition to these three main phases, Y2(Ti1-yZry)2O7 pyrochlore is also detected as minor phase for titania contents from 10 to 20 mol%. In the case of composites obtained for a fixed 10 mol% titania content varying the sintering temperatures leads only to a variation of the relative amount of the two main titania-doped YSZ and titania-doped YTZP phases. The total ionic conductivity of the composites, measured by impedance spectroscopy, decreases as the titania content increases, showing a sharp drop for doping concentrations above 15 mol%. In agreement with these results the Ti K-edge X-ray absorption spectroscopy (XAS) study shows that this behavior has been related not only to the sequential crystallization of the different phases but also to the ability of Ti to trap oxygen vacancies due to its occurrence in a disordered sixfold Ti-O arrangement. In contrast, the variation of the sintering temperature has little influence on both the ionic conductivity and the composite structure.

Journal Keywords: Ceramics; YSZ; Titania; Electrical transport; Synchrotron radiation

Diamond Keywords: Fuel Cells

Subject Areas: Materials, Chemistry, Energy

Instruments: B18-Core EXAFS

Other Facilities: XAFS at ELETTRA

Added On: 25/07/2016 13:53

Discipline Tags:

Energy Storage Energy Materials Engineering & Processes Ceramics Physical Chemistry Chemistry Materials Science Engineering & Technology

Technical Tags:

Spectroscopy X-ray Absorption Spectroscopy (XAS) Extended X-ray Absorption Fine Structure (EXAFS)