Zhang Leilei, Wu Qiang, Li Shourui, Sun Yi, Yan Xiaozhen, Chen Ying, Geng Hua Y
National Key Laboratory of Shock Wave and Detonation Physics, Institute of Fluid Physics, China Academy of Engineering Physics, P.O. Box 919-102, Mianyang, Sichuan 621900, P. R. China.
Jiangxi University of Science and Technology, Ganzhou, Jiangxi 341000, P. R. China.
ACS Appl Mater Interfaces. 2021 Feb 10;13(5):6130-6139. doi: 10.1021/acsami.0c17095. Epub 2021 Jan 28.
Electrides are an emerging class of materials with highly localized electrons in the interstices of a crystal that behave as anions. The presence of these unusual interstitial quasi-atom (ISQ) electrons leads to interesting physical and chemical properties and wide potential applications for this new class of materials. Crystal defects often have a crucial influence on the properties of materials. Introducing impurities has been proved to be an effective approach to improve the properties of a material and to expand its applications. However, the interactions between the anionic ISQs and the crystal defects in electrides are yet unknown. Here, dense fcc-Li was employed as an archetype to explore the interplay between anionic ISQs and interstitial impurity atoms in this electride. This work reveals strong coupling among the interstitial impurity atoms, the ISQs, and the matrix Li atoms near to the defects. This complex interplay and interaction mainly manifest as the unexpected tetrahedral interstitial occupation of impurity atoms and the enhancement of electron localization in the interstices. Moreover, the Be impurity occupying the octahedral interstice shows the highest negative charge state (Be) discovered thus far. These results demonstrate the rich chemistry and physics of this emerging material and provide a new basis for enriching their variants for a wide range of applications.
电子化物是一类新兴材料,其晶体间隙中存在高度局域化的电子,这些电子表现为阴离子。这些不同寻常的间隙准原子(ISQ)电子的存在导致了这类新材料有趣的物理和化学性质以及广泛的潜在应用。晶体缺陷通常对材料的性质有至关重要的影响。已证明引入杂质是改善材料性质并拓展其应用的有效方法。然而,电子化物中阴离子ISQ与晶体缺陷之间的相互作用尚不清楚。在此,以密排面心立方锂作为典型来探究这种电子化物中阴离子ISQ与间隙杂质原子之间的相互作用。这项工作揭示了间隙杂质原子、ISQ以及缺陷附近的基体锂原子之间的强耦合。这种复杂的相互作用和相互影响主要表现为杂质原子意外的四面体间隙占据以及间隙中电子局域化的增强。此外,占据八面体间隙的铍杂质表现出迄今为止所发现的最高负电荷态(Be)。这些结果证明了这种新兴材料丰富的化学和物理性质,并为丰富其变体以实现广泛应用提供了新的基础。