A new topological semimetal candidate: SmMnBi2
The new compound SmMnBi2 has been synthesized by the self-flux method and shown to crystallize in space group I4/mmm with a = 4.5054(4)Å, c = 20.5914(19)Å and Z = 4. Its structure comprises two-dimensional square Mn-nets layers, puckered rock-salt-like SmBi slabs and two-dimensional square Bi-nets layers, alternating along the c axis in an...Mn-net-SmBi slab-Bi-net-SmBi slab-Mn-net... sequence. Surprisingly, the atomic arrangement differs from its neighboring compound EuMnBi2 which has similar layers but with a different stacking arrangement. This gives rise to edge-shared square planar MnBi4 polyhedral layers in SmMnBi2 while EuMnBi2 has edge-shared MnBi4 tetrahedral layers. The MMnX 2 (M = alkaline earth/rare earth metals, X = Sb/Bi) family has emerged as topological Dirac or Weyl semimetal candidates, all of them sharing similar structural features. Although SmMnBi2 has a different stacking arrangement to EuMnBi2, its layer structure still makes it a topological Dirac or Weyl semimetal candidate.
Physics, Astronomy, and Materials Science
Dirac or Weyl semimetals, single crystal growth, SmMnBi 2, topological materials
Krishnan, Sudha, and Tiglet Besara. "A new topological semimetal candidate: SmMnBi2." Acta Crystallographica Section B: Structural Science, Crystal Engineering and Materials 77, no. 4 (2021): 577-583.
Acta Crystallographica Section B: Structural Science, Crystal Engineering and Materials