Phase assembly and electrical conductivity of spark plasma sintered CeO2–ZrO2 ceramics

Ce x Zr1−x O2 (x = 0.10, 0.16 and 0.33) nanocrystalline powders were obtained by a two-step synthesis technique and sintered by spark plasma sintering (SPS). As consequence of the reduction of Ce4+ to Ce3+ species by carbon in the graphite environment in SPS, phase assemblies including tetragonal, m...

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Bibliographic Details
Authors: Poyato, Rosalía, Cruz, Sylvia A., Cumbrera, Francisco Luis, Moreno, Berta, Chinarro Martín, Eva, Odriozola, José Antonio
Format: article
Publication Date:2014
Country:España
Institution:Consejo Superior de Investigaciones Científicas (CSIC)
Repository:DIGITAL.CSIC. Repositorio Institucional del CSIC
OAI Identifier:oai:digital.csic.es:10261/99809
Online Access:http://hdl.handle.net/10261/99809
Access Level:Open access
Keyword:CeO2–ZrO2
Spark plasma sintering
Pyrochlore
Electrical conductivity
Description
Summary:Ce x Zr1−x O2 (x = 0.10, 0.16 and 0.33) nanocrystalline powders were obtained by a two-step synthesis technique and sintered by spark plasma sintering (SPS). As consequence of the reduction of Ce4+ to Ce3+ species by carbon in the graphite environment in SPS, phase assemblies including tetragonal, monoclinic and pyrochlore phases were generated in the ceramics during the sintering process. The electrical conductivity was highly dependent on phase assembly and atmosphere (N2, H2 and O2). A significant decrease in the activation energy was noticed in the ceramics with high pyrochlore content when measuring the conductivity in H2 atmosphere, consequence of the strong reduction promoted in these ceramics during the measurement. Equal conduction behavior with similar activation energy was observed in all the ceramics when measuring in O2 atmosphere