Effect of bismuth addition on the electrical conductivity of gadolinium-doped ceria ceramics

✍ Scribed by Yen-Pei Fu; Chien-Wei Tseng; Po-Chin Peng

• Publisher: Elsevier Science
• Year: 2008
• Tongue: English
• Weight: 930 KB
• Volume: 28
• Category: Article
• ISSN: 0955-2219
• DOI: 10.1016/j.jeurceramsoc.2007.05.002

✦ Synopsis

The structure, thermal expansion and electrical conductivity of Ce 0.8 (Gd 1-x Bi x ) 0.2 O 1.9 (x = 0.1-0.5), prepared by coprecipitation were investigated. Ce 0.8 (Gd 1-x Bi x ) 0.2 O 1.9 ceramics was sintered in the range of 1350-1450 • C for 6 h; the bulk density of Ce 0.8 (Gd 1-x Bi x ) 0.2 O 1.9 ceramics was over 95% of the theoretical density; the maximum electrical conductivity, σ 800 • C = 0.078 S/cm with minimum activation energy, E a = 0.638 eV was found for the Ce 0.8 (Gd 0.5 Bi 0.5 ) 0.2 O 1.90 ceramic. The gadolinium-doped ceria ceramics preparation by coprecipitation can reduce the sintering temperature by addition of bismuth. The thermal expansion coefficient of Ce 0.8 (Gd 1-x Bi x ) 0.2 O 1.9 covers the range of 20.132-20.478 ppm/ • C. The ceramic has a fracture toughness in the range of 1.28-2.60 MPa m 1/2 for dense Ce 0.8 (Gd 1-x Bi x ) 0.2 O 1.9 ceramics. The value of fracture toughness increased with Bi content. It indicated that the mechanical properties of gadolinium-doped ceria ceramics could be improved by addition of bismuth.