Synthesis and Characterization of Zirconium Oxide Systems with Yttrium Rich Rare Earth Concentrate Additives

Abstract:

In this work, the yttrium rich rare earth concentrate (Re₂(CO₃)₃) was used as additive aiming stabilization of cubic an tetragonal phases at commercial zirconium oxide with 3% mol of yttrium oxide. The use of high purity rare earth oxide as additive is being commercially used and this work aims to demonstrate the potential use of lower cost additives to produce solid electrolyte for oxygen sensors and fuel cell applications. The powders for the additive production were synthesized by the controlled precipitation method. After synthesis, the powders were de-agglomerated using mechanical grinding and mixed to commercial zirconia to produce the compositions ZrO₂:3% Mol Y₂O₃:ƞ % Mol Re₂O₃ (ƞ=3,4,5,6), followed by uniaxial press and sintering at 1500 ⁰C in two hours. The obtained sintered densities were above 96% of theoretical. X-Ray diffractometric analysis and Rietweld refinement demonstrated the stabilization of cubic and tetragonal phases for all samples with yttrium rich rare earth concentrate additives. Finally the electric behavior of the evaluated samples was carried out with complex impedance spectroscopy, showing conductivity improvement for samples with the chosen additive. At 500 ⁰C the sample A-9% had a conductivity of 1,11E^-3 Ω^-1.cm^-1, well above of the sample without additive with conductivity 5,88E^-4 Ω¹.cm^-1, indicative that use of yttrium rich rare earth concentrate as additive increases considerably the ionic conductivity of comercial zirconium oxide. Key words: rare earth concentrate, controlled precipitation, ionic conductivity

• Periodical: Materials Science Forum (Volumes 798-799)
• Pages: 174-181
• DOI: https://doi.org/10.4028/www.scientific.net/MSF.798-799.174
• Online since: June 2014
• Authors: Paola Cristina Cajas*, R. Muñoz, A.C. Rodríguez, J.E. Rodríguez-Páez, C.R.M. da Silva
• Keywords: Controlled Precipitation, Ionic Conductivity, Rare Earth Concentrate

References

[1] Carda J., Alarcón J., Rincón J. M, (1992) Nuevos productos y tecnologías de esmaltes y pigmentos cerámicos. Su fabricación y utilización, Sociedad Española de Cerámica y Vidrio, Castellón de la Plana.

DOI: 10.3989/cyv.2000.v39.i5.777

[2] Mineiro, (2008), Processamento e Caracterização Física e Mecânica de Cerâmicas de Zircônia-Ítria Total e Parcialmente Nanoestruturadas. Tese de Doutorado. Instituto Nacional de Pesquisas Espaciais-INPE, São José dos Campos.

[3] Peters C. (2008). Grain-Size Effects in Nanoscaled Electrolyte and Cathode Thin Films for Solid Oxide Fuel Cells (SOFC)., Schriftendes Institut für Werkstoffe der Elektro technik, Universität Karlsruhe (TH).

[4] Tadokoro S. K., Muccillo E. N. S. (2000), Zircônia Tetragonal policristalina. arte II: Microestrutura e Resistividade Elétrica., Cerâmica Vol. 46, 230.

DOI: 10.1590/s0366-69132001000200007

[5] Muñoz, R (2010).

[6] Hwang, M. K. (2006).

[7] Putvinskis, (2003). Curvas de Calibração para Análise Quantitativa de Fases de Zircônias,. Laboratório Computacional de Análises Cristalografias e Cristalinas LabCACC. Universidade Estadual Paulista Araraquara.

[8] Brook, R. J. (181). reparation and Eletrical Behavior of Zirconia Ceramics., Am. Ceramic. Soc. Vol 3. (272-85).

[9] Caprioni E. (2007), Eletrólitos Sólidos à Base de óxido de Zircônio para a Detecção de Oxigênio. Tese de Doutorado, Instituto de pesquisas Energéticas e Nucleares-IPEN.

DOI: 10.11606/d.85.2003.tde-26062007-134849

[10] D.Z. Florio, F. C. Fonseca, E. N. S. Muccillo, R. Muccillo (2004), Materiais cerâmicos para células a combustível, Cerâmica 50, 275-290.

DOI: 10.1590/s0366-69132004000400002