Canted antiferromagnetic phases in the candidate layered Weyl material EuMnSb 2
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- Ames Lab., Ames, IA (United States); Iowa State Univ., Ames, IA (United States)
- Ames Lab., Ames, IA (United States)
- Univ. of Missouri, Columbia, MO (United States)
- Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)
- Iowa State Univ., Ames, IA (United States)
- McGill Univ., Montreal, QC (Canada)
EuMnSb2 is a candidate topological material which can be tuned towards a Weyl semimetal, but there are differing reports for its antiferromagnetic (AFM) phases. The coupling of bands dominated by pure Sb layers hosting topological fermions to Mn and Eu magnetic states provides a potential path to tune the topological properties. In this study we present single-crystal neutron diffraction, magnetization, and heat-capacity data as well as polycrystalline 151Eu Mössbauer data which show that three AFM phases exist as a function of temperature, and we present a detailed analysis of the magnetic structure in each phase. The Mn magnetic sublattice orders into a C-type AFM structure below TNMn= 323 (1) K with the ordered Mn magnetic moment μMn lying perpendicular to the layers. AFM ordering of the Eu sublattice occurs below TNEu1= 23 (1) K with the ordered Eu magnetic moment μEu canted away from the layer normal and μMn retaining its higher temperature order. μEu is ferromagnetically aligned within each Eu layer but exhibits a complicated AFM layer stacking. Both of these higher-temperature phases are described by magnetic space group (MSG) $$\mathcal{Pn'm'a'}$$ with the chemical and magnetic unit cells having the same dimensions. Cooling below TNEu2=9 (1) K reveals a third AFM phase where μMn remains unchanged but μEu develops an additional substantial in-plane canting. This phase has MSG $$\mathcal{P11}$$ $$\frac{2_1}{a′}$$. We also find some evidence of short-range magnetic correlations associated with the Eu between 12 K≲ T≲ 30 K . Using the determined magnetic structures, we postulate the signs of nearest-neighbor intralayer and interlayer exchange constants and the magnetic anisotropy within a general Heisenberg model. We then discuss implications of the various AFM states in EuMnSb2 and their potential for tuning topological properties.
- Research Organization:
- Ames Laboratory (AMES), Ames, IA (United States); Energy Frontier Research Centers (EFRC) (United States).Center for Advancement of Topological Semimetals (CATS); Oak Ridge National Laboratory (ORNL), Oak Ridge, TN (United States). Spallation Neutron Source (SNS)
- Sponsoring Organization:
- USDOE Office of Science (SC), Basic Energy Sciences (BES); Fonds Québécois de la Recherche sur la Nature et les Technologies; Natural Sciences and Engineering Research Council of Canada (NSERC)
- Grant/Contract Number:
- AC02-07CH11358; AC05-00OR22725
- OSTI ID:
- 1881884
- Alternate ID(s):
- OSTI ID: 1902798
- Report Number(s):
- IS-J-10,869; TRN: US2307877
- Journal Information:
- Physical Review. B, Vol. 106, Issue 2; ISSN 2469-9950
- Publisher:
- American Physical Society (APS)Copyright Statement
- Country of Publication:
- United States
- Language:
- English
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