Premium
A new topological semimetal candidate: SmMnBi 2
Author(s) -
Krishnan Sudha,
Besara Tiglet
Publication year - 2021
Publication title -
acta crystallographica section b
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.604
H-Index - 33
ISSN - 2052-5206
DOI - 10.1107/s2052520621005849
Subject(s) - semimetal , stacking , dirac (video compression format) , weyl semimetal , net (polyhedron) , materials science , condensed matter physics , crystallography , topology (electrical circuits) , physics , band gap , chemistry , geometry , nuclear magnetic resonance , quantum mechanics , neutrino , mathematics , combinatorics
The new compound SmMnBi 2 has been synthesized by the self‐flux method and shown to crystallize in space group I 4/ 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 EuMnBi 2 which has similar layers but with a different stacking arrangement. This gives rise to edge‐shared square planar MnBi 4 polyhedral layers in SmMnBi 2 while EuMnBi 2 has edge‐shared MnBi 4 tetrahedral layers. The M Mn X 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 SmMnBi 2 has a different stacking arrangement to EuMnBi 2 , its layer structure still makes it a topological Dirac or Weyl semimetal candidate.