Structure and Electrons in Mayenite Electrides

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• 作者：Luis Palacios ; Aurelio Cabeza ; Sebastiá ; n Bruque ; Santiago Garc&#xed ; a-Granda ; Miguel A. G. Aranda
• 刊名：Inorganic Chemistry
• 出版年：2008
• 出版时间：April 7, 2008
• 年：2008
• 卷：47
• 期：7
• 页码：2661 - 2667
• 全文大小：6070K
• 年卷期：v.47,no.7(April 7, 2008)
• ISSN：1520-510X

文摘

One major goal in materials chemistry is to find inexpensive compounds with improved capabilities. Stable inorganic electrides, derived from nanoporous mayenite [Ca₁₂Al₁₄O₃₂]O, are a new family that has very interesting properties such as electronic conductivity combined with transparency. However, an intriguing fundamental problem is to understand the structures of these cubic materials and to characterize their free-electron loadings. Here we report an accurate structural study for three members of the series [Ca₁₂Al₁₄O₃₂]O_1−δe_2δ (δ = 0, 0.15, and 0.45), from single-crystal low-temperature synchrotron X-ray diffraction. The complex structural disorder imposed by the presence of the oxide anions into the mayenite cages has been unravelled. Furthermore, the final electron density map for δ = 0.45 black mayenite has shown electron density localized into the center of the cages, which is the first experimental proof of their electride nature. The reported structural findings challenge theorists to improve predictive models in this new family of materials.