Preparation and Electrical Characterization of Ruthenia-Doped Yttria-Stabilized Zirconia Ceramics

✍ Scribed by M.T. Colomer; J.R. Jurado

• Publisher: Elsevier Science
• Year: 1998
• Tongue: English
• Weight: 306 KB
• Volume: 141
• Category: Article
• ISSN: 0022-4596
• DOI: 10.1006/jssc.1998.8004

✦ Synopsis

Samples belonging to the [(ZrO 2 ) 0.92 (Y 2 O 3 ) 0.08 ] 1؊x (RuO 2 ) x system, where 04x40.1 (mol), have been synthesized by a polymeric sol-gel route and sintered in air at 1400°C for 2 h. The RuO 2 -YSZ solid solution limit is found at x ‫؍‬ 0.05 at 1400°C by X-ray diffraction and electrochemical impedance spectroscopy measurements. The electrical conductivity of the studied materials decreases with ruthenia additions. At high temperature (700-850°C) and low oxygen partial pressure, these materials behave as mixed oxygen ion-electronic conductors. The electronic conductivity as a function of P O shows a dependence of ؊1/4 and an activation energy of 0.98 eV. The electronic contribution is explained on the basis of redox equilibrium between trivalent Ru 3؉ and divalent Ru 2؉ . The EPR spectra of polycrystalline sintered samples confirm the presence of Ru 3؉ .