Title: Magnetic and electronic structures of antiferromagnetic topological material candidate EuMg₂Bi₂

Abstract

In this work, EuMg₂Bi₂ has been investigated to understand the electronic and magnetic behaviors as an antiferromagnetic (AFM) topological semimetal candidate. High-quality single crystals of EuMg₂Bi₂ were grown via a Bi flux and, subsequently, characterized to be consistent with the previously reported bulk magnetic and resistivity properties. A ferromagnetic interaction is indicated by the positive Curie–Weiss temperature obtained through fitting the bulk magnetic susceptibility data. The bulk resistivity measurements reveal an interesting electronic behavior that is potentially influenced by a competing antiferromagnetic and ferromagnetic interaction in and out of the ab plane. From the resulting refinement of the neutron diffraction data, EuMg₂Bi₂ was found to exhibit an A-type magnetic structure with Eu²⁺ moments ferromagnetically aligned in the plane and antiferromagnetically stacked between neighbor ferromagnetic Eu layers. The power law fitting magnetic ordering parameter below TN~8 K agrees with the 2D Heisenberg model, indicating a weak interlayer antiferromagnetic interaction. Considering the magnetic structure determined by neutron diffraction, the surface state calculation suggests that EuMg₂Bi₂ is an AFM topological insulator candidate. Linearly dispersed Dirac surface states were also observed in our angle-resolved photoemission spectroscopy measurements, consistent with the calculation.

Authors:

Marshall, Madalynn ^[1]; Pletikosić, Ivo  ^[2];

• Search DOE PAGES for author "Pletikosić, Ivo"
• Search DOE PAGES for ORCID "0000-0003-4697-8912"

Yahyavi, Mohammad ^[3]; Tien, Hung-Ju  ^[3];

• Search DOE PAGES for author "Tien, Hung-Ju"
• Search DOE PAGES for ORCID "0000-0002-3789-3928"

Chang, Tay-Rong ^[4]; Cao, Huibo  ^[5];

• Search DOE PAGES for author "Cao, Huibo"
• Search DOE PAGES for ORCID "0000-0002-5970-4980"

Xie, Weiwei  ^[6]

• Search DOE PAGES for author "Xie, Weiwei"
• Search DOE PAGES for ORCID "0000-0002-5500-8195"

---

+ Show Author Affiliations

1. Rutgers Univ., Piscataway, NJ (United States); Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)
2. Princeton Univ., NJ (United States)
3. National Cheng Kung Univ., Tainan City (Taiwan)
4. National Cheng Kung Univ., Tainan City (Taiwan); Center for Quantum Frontiers of Research and Technology (QFort), Tainan City (Taiwan)
5. Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)
6. Rutgers Univ., Piscataway, NJ (United States)

Publication Date:

Tue Jan 19 00:00:00 EST 2021

Research Org.:

Oak Ridge National Laboratory (ORNL), Oak Ridge, TN (United States)

Sponsoring Org.:

USDOE Office of Science (SC), Basic Energy Sciences (BES); National Science Foundation (NSF); Ministry of Science and Technology (MOST) (Taiwan)

OSTI Identifier:

1763448

Alternate Identifier(s):

OSTI ID: 1970658

Grant/Contract Number:  

AC05-00OR22725; KC0402010; DMR-2053287; MOST109-2636-M-006-002; MOST107-2627-E-006-001; Office of Science Graduate Student Research (SCGSR) fellowship program

Resource Type:

Accepted Manuscript

Journal Name:

Journal of Applied Physics

Additional Journal Information:

Journal Volume: 129; Journal Issue: 3; Journal ID: ISSN 0021-8979

Publisher:

American Institute of Physics (AIP)

Country of Publication:

United States

Language:

English

Subject:

36 MATERIALS SCIENCE