Space-charge conduction in yttria and alumina codoped-zirconia 1

✍ Scribed by Xin Guo

• Book ID: 104296465
• Publisher: Elsevier Science
• Year: 1997
• Tongue: English
• Weight: 721 KB
• Volume: 96
• Category: Article
• ISSN: 0167-2738
• DOI: 10.1016/s0167-2738(96)00593-0

✦ Synopsis

The grain-boundary resistances of 9 mot% Y,O, and 1.5 mol% Al,O, codoped-ZrO, after sinterings of 1520-1600°C

were measured by the complex impedance approach. And the microstructure of the specimen was analyzed by means of SEM, EPMA and TEM. According to a space-charge theory analysis, the space-charge potential of the Y,O, and Al,O,-codoped ZrO, is negative, which is the result of an A& segregation and a Vi depletion in the space-charge layers. As Al;, has a stronger tendency to form associates with Vi than Ylr, the Al& segregation further reduces the concentration of mobile Vi in the space-charge layers, thus increasing the grain-boundary resistance contributed from the space-charge layers. A higher Vi concentration in the space-charge layers of the Al,O,/ZrO, is suggested by the space-charge theory, but due to the pores and the amorphous phases covering the AI,O, particles, the effect of the space-charge layers with high Vi; concentration will not be very obvious.