Li Wei-Bang, Lin Shih-Yang, Tran Ngoc Thanh Thuy, Lin Ming-Fa, Lin Kuang-I
Department of Physics, National Cheng Kung University Tainan Taiwan
Department of Physics, National Chung Cheng University Chiayi Taiwan.
RSC Adv. 2020 Jun 30;10(40):23573-23581. doi: 10.1039/d0ra00639d. eCollection 2020 Jun 19.
The rich and unique properties of the stage- graphite alkali-metal-intercalation compounds are fully investigated by first-principles calculations. According to the main features, the lithium and non-lithium (Na, K, Rb, Cs) systems are quite different from each other in stacking configurations, intercalant alkali-metal-atom concentrations, free conduction electron densities, atom-dominated and (carbon, alkali metal)-co-dominated energy bands, and interlayer charge density distributions. The close relations between the alkali-metal-doped metallic behaviors and the geometric symmetries are clarified through the interlayer atomic interactions. The stage-1 graphite alkali-metal-intercalation compounds possess the highest charge distribution for all stage- types; moreover, those of the lithium systems are greater than those of the non-lithium systems. The lithium systems also have the largest blue shift of the Fermi level among all alkali metal systems.
通过第一性原理计算对石墨-碱金属插层化合物的丰富独特性质进行了全面研究。根据主要特征，锂体系和非锂体系（钠、钾、铷、铯）在堆积构型、插层碱金属原子浓度、自由传导电子密度、原子主导和（碳、碱金属）共同主导的能带以及层间电荷密度分布等方面存在很大差异。通过层间原子相互作用阐明了碱金属掺杂金属行为与几何对称性之间的密切关系。对于所有阶段类型，1阶石墨-碱金属插层化合物具有最高的电荷分布；此外，锂体系的电荷分布大于非锂体系。在所有碱金属体系中，锂体系的费米能级蓝移也最大。
