The Structure of Terbium in the Ferromagnetic State

作者：Lin, Kun; Li, Guodong; Khmelevskyi, Sergii; Pourovskii, Leonid V.; Jiang, Suihe; Kato, Kenichi; Yu, Chengyi; Cao, Yili; Li, Qiang; Kuang, Xiaojun; Xing, Xianran^*

来源：Journal of the American Chemical Society, 2023, 145(32): 17856-17862.

DOI：10.1021/jacs.3c04931

• HIGH-TEMPERATURE ALLOTROPY
• HIGH-PRESSURE PHASE
• THERMAL-EXPANSION
• CRYSTAL-STRUCTURE
• MAGNETOELASTIC PROPERTIES
• MAGNETIC-PROPERTIES
• CERIUM METAL
• SYSTEMS

Metals typically crystallize in highly symmetric structuresdueto their nondirectional and nonsaturated metallic bonds. Here, wereport that terbium metal in its ferromagnetic state adopts an unusuallow-symmetry orthorhombic structure with a Cmcm spacegroup. A similar structure has been previously observed only in afew actinide metals with bonding 5f electrons at ambient pressure,such as uranium, neptunium, and plutonium, but with different nearestcoordination numbers and bond-length variations. The Tb atom occupiesthe 4c site (0, & SIM;0.1661, 1/4), building up -[Tb-Tb]-layers stacking along the b-axis. Our first-principlesmany-body calculations of the crystal field splitting in the correlatedTb 4f-shell demonstrate that the Cmcm structure forferromagnetic terbium is stabilized by magneto-elastic forces dueto a secondary order of quadrupolar moments in the ferromagnetic state.These findings are significant for further understanding of the natureof terbium, including its electron structure, energy bands, phonons,and magnetism.

• 单位
  桂林理工大学; 北京科技大学