Preparation of Porous Zirconia-Yttria Ceramics by Thermal Removal of Potassium Iodide

Abstract:

Zirconia-8 mol% yttria porous solid electrolytes were obtained by mixing with different amounts (0 to 5 wt.%) of KI prior to sintering. Potassium iodide acts as sacrificial pore former, being removed from the ceramic pellet upon sintering at 1400 °C/2 h. The alkali halide content was evaluated by X-ray fluorescence analysis, the density of the pellets by the Archimedes method, and the pore content by observation in scanning probe (SPM) and scanning electron (SEM) microscopes of polished and etched surfaces. The oxide ion resistivity was determined by impedance spectroscopy analysis in the 5 Hz-13 MHz frequency range from 300 to 500 °C. Porous specimens with high skeletal density were obtained. The higher is the alkali halide content, the higher is the pore volume and the total electrical resistivity. A correlation is found between the pore content, evaluated by SEM and SPM, and the electrical behavior analysis from the impedance plots of the porous specimens.

• Periodical: Materials Science Forum (Volumes 798-799)
• Pages: 391-395
• DOI: https://doi.org/10.4028/www.scientific.net/MSF.798-799.391
• Online since: June 2014
• Authors: Sabrina Gonçalves Macedo Carvalho*, R. Muccillo
• Keywords: Porous Ceramics, Zirconia-Yttria

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