An Anomalous Electron Configuration Among 3d Transition Metal Atoms

• Published in: Angewandte Chemie (International ed.) 2022-12, Vol.62 (7)
• Main Authors: Tang, Zhexin, Shang, Tongtong, Xu, Han, Lin, Ting, Gao, Ang, Lin, Weiguang, Li, Xinyan, Wang, Shiyu, Yu, Botao, Meng, Fanqi, Zhang, Qinghua, Wang, Xuefeng, Su, Dong, Meng, Qingbo, Wu, Lijun, Gu, Lin, Nan, Ce‐Wen
• Format: Article
• Language: English
• Subjects: Electron Configuration; Electron Density Distribution; Electron Microscopy; MATERIALS SCIENCE; Quantitative Convergent-Beam Electron Diffraction; Scandium
• ISSN: 1433-7851; 1521-3773

Physical properties of materials are mainly determined by valence electron configurations, where different valence shells would induce divergent phenomena. In compounds containing Sc2+, 3d electron occupancy is expected, same as other transition metal atoms like Ti3+. But this situation still awaits experimental verification. In this work, we selected ScS to measure the valence electron density and orbital population of Sc2+ through delicate quantitative convergent-beam electron diffraction. Though the [Ar]3d1 configuration is confirmed in ionic Sc2+, the unintuitive occupation of 4s orbital is concluded with the absence of 3d orbital features around Sc-atom sites and nearly bare population of t2g orbital. It should be the first time to report this special electron configuration in a transition metal compound, in which 4s rather than 3d orbital is preferred. Our findings reveal the distinct behavior of Sc, and probable ways to modulate material properties by controlling electron orbitals.