Defect Chemistry of the Mixed Conducting Cage Compound Ca12Al14O33
- Defect Chemistry of the Mixed Conducting Cage Compound Ca12Al14O33
- J. Janek; 이도권
- mayenite; Ca12Al14O33; electronic conductivity; ionic conductivity; defect structure; C12A7
- Issue Date
- 한국세라믹학회지; Journal of the Korean Ceramic Society
- VOL 47, NO 2, 99-105
- The electrical transport properties of mayenite (Ca12Al14O33 or 12CaO·7Al2O3; mostly abbreviated as C12A7) can be controlled in a
wide range by varying the oxygen deficiency: At high temperatures mayenite becomes either an oxygen solid electrolyte, a mixed
ionic/electronic conductor or an inorganic electride with metal-like properties upon chemical reduction (removing oxygen). The underlying
defect chemistry can be understood on the basis of a relatively simple model – despite the complex cage structure: A point defect
model based on the assumption that the framework [Ca12Al14O32]2+ acts as a pseudo-donor describes well the high temperature transport
properties. It accounts for the observed conductivity plateau at higher oxygen activities and also describes the experimentally
observed oxygen activity dependence of the electronic conductivity with −1/4 slope at temperatures between 800 and 1000℃. Doping
effects in mayenite are still not well explored, and we review briefly the existing data on doping by different elements. Hydration of
mayenite plays a crucial role, as Mayenite is hygroscopic, which may be a major obstacle for technical applications.
- Appears in Collections:
- KIST Publication > Article
- Files in This Item:
There are no files associated with this item.
- RIS (EndNote)
- XLS (Excel)
Items in DSpace are protected by copyright, with all rights reserved, unless otherwise indicated.