Janek, J. Lee, D.-K. 2024-01-20T19:34:49Z 2024-01-20T19:34:49Z 2021-09-02 2010-03 1229-7801 https://pubs.kist.re.kr/handle/201004/131672 The electrical transport properties of mayenite (Ca12Al 14O33 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 [Ca12Al14O 32]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°C. 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. English C12a7 Ca12al14o33 Cage compounds Cage structures Chemical reduction Defect chemistry Doping effects Electrical transport properties Electrides Electronic conductivity High temperature High-temperature transport properties Mayenite Metal-like properties Oxygen activity Oxygen deficiency Point defect models Technical applications Aluminum Astatine Calcium Driers (materials) Electric properties Ionic conductivity Oxygen Point defects Solid electrolytes Transport properties Defect structures Defect chemistry of the mixed conducting cage compound Ca 12Al14O33 Article 10.4191/KCERS.2010.47.2.099 1 Journal of the Korean Ceramic Society, v.47, no.2, pp.99 - 105 Journal of the Korean Ceramic Society 47 2 99 105 scopus kci 2-s2.0-78649860700 Article C12a7 Ca12al14o33 Cage compounds Cage structures Chemical reduction Defect chemistry Doping effects Electrical transport properties Electrides Electronic conductivity High temperature High-temperature transport properties Mayenite Metal-like properties Oxygen activity Oxygen deficiency Point defect models Technical applications Aluminum Astatine Calcium Driers (materials) Electric properties Ionic conductivity Oxygen Point defects Solid electrolytes Transport properties Defect structures C12a7 Ca12al14o33 Defect structure Electronic conductivity Ionic conductivity Mayenite