Processing and thermal properties of mayenite electride

• DOI: 10.1111/jace.17646
• Publication Date: 2020-12-28T21:23:16Z
• Authors: Jon Mackey; Tyson Back; Marie‐Hélène Berger; Ali Sayir
• Keywords: [SPI]Engineering Sciences [physics]; 01 natural sciences; 7. Clean energy; 0104 chemical sciences

AbstractA mayenite‐based electride is being considered for field emitter applications where it will be critical to have a good understanding of processing repeatability and thermal properties. This paper focuses on the details of processing of mayenite compounds in a strongly reducing graphite environment to form an electride solid‐solution phase as Ca12Al14O32(C2,O2)1‐x(e2)x. The work reports, in addition to processing details, several thermal properties. The electride phase was found to have coefficient of thermal expansion (CTE) of 7e‐6 K−1, thermal diffusivity between 0.0063 and 0.0102 cm2/s, and thermal conductivity between 1.9 and 3.1 W m−1 K−1. Rattling motion of O2− or C22− ions in cage structure has been suggested to explain low thermal conductivity of the electride phase.