AEMnSb<sub>2</sub>(AE=Sr, Ba): a new class of Dirac materials

Farhan, M. Arshad; Lee, Geunsik; Shim, Ji Hoon

doi:10.1088/0953-8984/26/4/042201

Cited by 68 publications

(80 citation statements)

References 16 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Manganese (Mn) based pnictide compounds with MnP n (P n = P, As, Sb, and Bi) layers have been in the spotlight by virtue of their intriguing magnetic properties, most notably the recently discovered Dirac semimetals AMnP n 2 (A = Ca, Sr, and Ba) [1][2][3]. The quasi two-dimensional (2D) AMnP n 2 have been recognized as the three-dimensional (3D) analogs of the 2D graphene with linearly dispersing bands that cross at the Fermi energy [2]. Generally, the Mn atoms are arranged in a square lattice or in a slightly distorted orthorhombic lattice and undergo antiferromagnetic (AFM) ordering.…”

Section: Introductionmentioning

confidence: 99%

Spin dynamics in antiferromagnetic oxypnictides and fluoropnictides: LaMnAsO, LaMnSbO, and BaMnAsF

et al. 2020

View full text Add to dashboard Cite

Inelastic neutron scattering (INS) from polycrystalline antiferromagnetic LaMnAsO, LaMnSbO, and BaMnAsF are analyzed using a J1 − J2 − Jc Heisenberg model in the framework of the linear spin-wave theory. All three systems show clear evidence that the nearest-and next-nearest-neighbor interactions within the Mn square lattice layer (J1 and J2) are both antiferromagnetic (AFM). However, for all compounds studied the competing interactions have a ratio of 2J2/J1 < 1, which favors the square lattice checkerboard AFM structure over the stripe AFM structure. The interplane coupling Jc in all three systems is on the order of ∼ 3 × 10 −4 J1, rendering the magnetic properties of these systems with quasi-two-dimensional character. The substitution of Sb for As significantly lowers the in-plane exchange coupling, which is also reflected in the decrease of the Néel temperature, TN. Although BaMnAsF shares the MnAs sheets as LaMnAsO, their J1 and J2 values are substantially different. Using density functional theory, we calculate exchange parameters Jij to rationalize the differences among these systems.arXiv:2001.02268v2 [cond-mat.str-el]

show abstract

Section: Introductionmentioning

confidence: 99%

Spin dynamics in antiferromagnetic oxypnictides and fluoropnictides: LaMnAsO, LaMnSbO, and BaMnAsF

et al. 2020

View full text Add to dashboard Cite

show abstract

“…Such control can potentially be realized in materials in which magnetic order coexists with non-trivial electronic band topology. Recent ARPES, quantum oscillation, neutron diffraction and ab initio band structure studies suggest that materials in the AMnSb 2 (A = Ca, Sr, Ba, Eu, Yb) family display many of the required properties [9][10][11][12][13][14][15][16][17][18] . The two-dimensional zig-zag layer of Sb atoms [ Fig.…”

mentioning

confidence: 99%

Magnetic and electronic structure of Dirac semimetal candidate EuMnSb2

et al. 2019

View full text Add to dashboard Cite

We report an experimental study of the magnetic order and electronic structure and transport of the layered pnictide EuMnSb2, performed using neutron diffraction, angle-resolved photoemission spectroscopy (ARPES), and magnetotransport measurements. We find that the Eu and Mn sublattices display antiferromagnetic (AFM) order below T Eu N = 21(1) K and T Mn N = 350(2) K respectively. The former can be described by an A-type AFM structure with the Eu spins aligned along the c axis (an in-plane direction), whereas the latter has a C-type AFM structure with Mn moments along the a-axis (perpendicular to the layers). The ARPES spectra reveal Dirac-like linearly dispersing bands near the Fermi energy. Furthermore, our magnetotransport measurements show strongly anisotropic magnetoresistance, and indicate that the Eu sublattice is intimately coupled to conduction electron states near the Dirac point. 75.30.Gw, 74.70.Xa Topological semimetals can host quasiparticle excitations which masquerade as massless fermions due to the linearly-dispersing electronic bands created by interactions with the crystal lattice. The Dirac or Weyl nodes, where the conduction and valence bands meet in momentum space, are robust against small perturbations due to the protection afforded by crystalline symmetries or the topology of the electronic bands 1-5 . Topological semimetals exhibit exceptional electronic transport properties (e.g. extremely high carrier mobility and large linear magnetoresistance) and the control of these exotic charge carriers could help realize a new generation of spintronic devices with low power consumption 6-8 .Such control can potentially be realized in materials in which magnetic order coexists with non-trivial electronic band topology. Recent ARPES, quantum oscillation, neutron diffraction and ab initio band structure studies suggest that materials in the AMnSb 2 (A = Ca, Sr, Ba, Eu, Yb) family display many of the required properties 9-18 . The two-dimensional zig-zag layer of Sb atoms [ Fig. 1] in these 112-pnictides play host to fermions which can be described by the relativistic Dirac or Weyl equations. Furthermore, the electronic transport in this family of materials also displays large magnetoresistive effects, suggesting a coupling between the magnetism and charge carriers 9-17 . These effects could be driven by changes in the electronic band structure topology due to changes in the symmetry of the spin structures induced by the applied field 19 .Within the AMnSb 2 family, EuMnSb 2 is of particular interest because the conducting zig-zag layer of Sb atoms is sandwiched between two interpenetrating magnetic sublattices (Eu and Mn), as shown in Fig. 1(a). Such a structure may lead to an enhancement of the coupling between the topological quasiparticles and mag-netism, compared to that in compounds with a nonmagnetic atom on the A site. The dramatic magnetoresistive behaviour observed in a recent work 20 is evidence for the importance of this coupling. Up to now, however, the nature of the magnetic order in...

show abstract

“…ARPES measurements have provided direct evidence for the existence of strongly anisotropic Dirac cones in SrMnBi 2 and CaMnBi 2 [16]. And first-principles calculations of AMnSb 2 (A = Sr, Ba; replacing Bi with Sb) have indicated Dirac fermionic behavior could be realized in BaMnSb 2 [17]. Subsequent transport and magnetization measurements and relativistic first-principles calculations have suggested that BaMnSb 2 is a 3D WSM by virtue of weak ferromagnetism due to canted Mn moments in the antiferromagnetic (AFM) structure [18].…”

Section: Introductionmentioning

confidence: 99%

Crystal growth, microstructure, and physical properties of SrMnSb2

Liu

Zhou

et al. 2019

Phys. Rev. B

View full text Add to dashboard Cite

We report on the crystal and magnetic structures, magnetic, and transport properties of SrMnSb2 single crystals grown by the self-flux method. Magnetic susceptibility measurements reveal an antiferromagnetic (AFM) transition at TN = 295(3) K. Above TN, the susceptibility slightly increases and forms a broad peak at T ∼ 420 K, which is a typical feature of two-dimensional magnetic systems. Neutron diffraction measurements on single crystals confirm the previously reported C-type AFM structure below TN. Both de Haas-van Alphen (dHvA) and Shubnikov-de Haas (SdH) effects are observed in SrMnSb2 single crystals. Analysis of the oscillatory component by a Fourier transform shows that the prominent frequencies obtained by the two different techniques are practically the same within error regardless of sample size or saturated magnetic moment. Transmission electron microscopy (TEM) reveals the existence of stacking faults in the crystals, which result from a horizontal shift of Sb atomic layers suggesting possible ordering of Sb vacancies in the crystals. Increase of temperature in susceptibility measurements leads to the formation of a strong peak at T ∼ 570 K that upon cooling under magnetic field the susceptibility shows a ferromagnetic transition at TC ∼ 580 K. Neutron powder diffraction on crushed single-crystals does not support an FM phase above TN. Furthermore, X-ray magnetic circular dichroism (XMCD) measurements of a single crystal at the L2,3 edge of Mn shows a signal due to induced canting of AFM moments by the applied magnetic field. All evidence strongly suggests that a chemical transformation at the surface of single crystals occurs above 500 K concurrently producing a minute amount of ferromagnetic impurity phase. * yongliu31@outlook.com † vaknin@ameslab.gov arXiv:1902.04948v1 [cond-mat.mtrl-sci]

show abstract

AEMnSb₂(AE=Sr, Ba): a new class of Dirac materials

Cited by 68 publications

References 16 publications

Spin dynamics in antiferromagnetic oxypnictides and fluoropnictides: LaMnAsO, LaMnSbO, and BaMnAsF

Spin dynamics in antiferromagnetic oxypnictides and fluoropnictides: LaMnAsO, LaMnSbO, and BaMnAsF

Magnetic and electronic structure of Dirac semimetal candidate EuMnSb2

Crystal growth, microstructure, and physical properties of SrMnSb2

Contact Info

Product

Resources

About

AEMnSb2(AE=Sr, Ba): a new class of Dirac materials

Cited by 68 publications

References 16 publications

Spin dynamics in antiferromagnetic oxypnictides and fluoropnictides: LaMnAsO, LaMnSbO, and BaMnAsF

Spin dynamics in antiferromagnetic oxypnictides and fluoropnictides: LaMnAsO, LaMnSbO, and BaMnAsF

Magnetic and electronic structure of Dirac semimetal candidate EuMnSb2

Crystal growth, microstructure, and physical properties of SrMnSb2

Contact Info

Product

Resources

About

AEMnSb₂(AE=Sr, Ba): a new class of Dirac materials