Antiferromagnetic structure in tetragonal CuMnAs thin films

Wadley, P.; Hills, V.; Shahedkhah, M. R.; Edmonds, K. W.; Campion, R. P.; Novák, V.; Ouladdiaf, B.; Khalyavin, D. D.; Langridge, S.; Saidl, V.; Němec, P.; Rushforth, A. W.; Gallagher, B. L.; Dhesi, S. S.; Maccherozzi, Francesco; Železný, Jakub; Jungwirth, T.

doi:10.1038/srep17079

Cited by 85 publications

(79 citation statements)

References 23 publications

(32 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The film has a Néel temperature of 480 K and a resistivity of 160 µΩcm. [7,10,23] Four-arm cross-shaped devices, with 10 µm wide arms oriented along the [100] and [010] crystal axes of the CuMnAs film ( Fig. 1(a)), were prepared by photolithography and wet chemical etching.…”

mentioning

confidence: 99%

“…XMLD contrast was obtained by taking PEEM images with x-ray energy at the Mn L 3 absorption edge (E 1 ) and at 0.9 eV below the edge (E 2 ). These correspond to the peak and the valley of the Mn L 3 XMLD spectrum, resulting in a ≈1% difference in absorption between regions with spin axis parallel or perpendicular to the x-ray polarization vector [23]. The x-ray absorption and XMLD spectra are shown in the Supplemental Material [24].…”

mentioning

confidence: 99%

See 1 more Smart Citation

Imaging Current-Induced Switching of Antiferromagnetic Domains in CuMnAs

et al. 2017

Self Cite

View full text Add to dashboard Cite

The magnetic order in antiferromagnetic materials is hard to control with external magnetic fields. Using X-ray Magnetic Linear Dichroism microscopy, we show that staggered effective fields generated by electrical current can induce modification of the antiferromagnetic domain structure in microdevices fabricated from a tetragonal CuMnAs thin film. A clear correlation between the average domain orientation and the anisotropy of the electrical resistance is demonstrated, with both showing reproducible switching in response to orthogonally applied current pulses. However, the behavior is inhomogeneous at the submicron level, highlighting the complex nature of the switching process in multi-domain antiferromagnetic films.Antiferromagnetic (AF) materials are of increasing interest both for fundamental physics and applications. Recent advances in detecting and manipulating AF order electrically have opened up new prospects for these materials in basic and applied spintronics research [1][2][3][4][5][6][7]. Of particular interest is the Néel order spin-orbit torque (NSOT) [6], recently demonstrated in the collinear AF CuMnAs [7], where a current-induced local spin polarization can exert a rotation of the magnetic sublattices. NSOT is closely analogous to the spin-orbit torque in ferromagnets with broken inversion symmetry, in which electrical currents induce effective magnetic fields that can be used to switch the magnetization direction [8,9]. The tetragonal CuMnAs lattice [10] is inversion symmetric, so that zero net spin polarization is generated by a uniform electric current. However, its Mn spin sublattices form inversion partners, resulting in local effective fields of opposite sign on the AF-coupled Mn sites [6,11]. These staggered current-induced fields can be large enough to cause a non-volatile rotation of the AF spin axis [7].Current-induced rotations of AF moments can be detected electrically using anisotropic magnetoresistance (AMR), a dependence on the relative orientation of the current and spin axes which is present in both ferromagnetic and AF materials [12][13][14][15]. This provides only spatially averaged information over the probed area of the device, which may be several microns or larger. PhotoEmission Electron Microscopy (PEEM), with contrast enabled by X-ray Magnetic Linear Dichroism (XMLD), provides direct imaging of AF domains with better than 100 nm resolution [16]. Based on differences in absorption of x-rays with linear polarization, XMLD-PEEM has offered valuable insights into the microscopic magnetic properties of AF films [17] and ferromagnet / AF interfaces [18,19]. The measured intensity varies as I 0 + I 2 cos 2 α, where α is the angle between the x-ray polarization and the spin axis [20], so is equally present for AF and FM materials, similar to AMR. The XMLD amplitude given by I 2 also depends on the orientation of the x-ray polarization with respect to the crystalline axes [21,22], and the signal is sensitive to domains within the top few nanometers of the surface.Here, we combin...

show abstract

mentioning

confidence: 99%

mentioning

confidence: 99%

Imaging Current-Induced Switching of Antiferromagnetic Domains in CuMnAs

et al. 2017

Self Cite

View full text Add to dashboard Cite

show abstract

“…The TET phase consists of alternating layers of edge-sharing CuAs 4 and MnAs 4 tetrahedra. It has been proposed to be a candidate with favourable applications in spintronics [18,19] and a topological metal-insulator transition driven by the Néel vector [17]. On the other hand, the ORT phase consists of a 3D network of edge-sharing CuAs 4 and MnAs 4 tetrahedra ( Fig.…”

mentioning

confidence: 99%

Magnetic order induces symmetry breaking in the single-crystalline orthorhombic CuMnAs semimetal

et al. 2017

View full text Add to dashboard Cite

Recently, orthorhombic CuMnAs has been proposed to be a magnetic material where topological fermions exist around the Fermi level. Here we report the magnetic structure of the orthorhombic Cu0.95MnAs and Cu0.98Mn0.96As single crystals. While Cu0.95MnAs is a commensurate antiferromagnet (C-AFM) below 360 K with a propagation vector of k = 0, Cu0.98Mn0.96As undergoes a second-order paramagnetic to incommensurate antiferromagnetic (IC-AFM) phase transition at 320 K with k = (0.1,0,0), followed by a second-order IC-AFM to C-AFM phase transition at 230 K. In the C-AFM state, the Mn spins order parallel to the b-axis but antiparallel to their nearest-neighbors with the easy axis along the b axis. This magnetic order breaks Ry gliding and S2z rotational symmetries, the two crucial for symmetry analysis, resulting in finite band gaps at the crossing point and the disappearance of the massless topological fermions. However, the spin-polarized surface states and signature induced by non-trivial topology still can be observed in this system, which makes orthorhombic CuMnAs promising in antiferromagnetic spintronics.Dirac cones have been proposed and observed in many non-magnetic materials, including Cd 3 As 2 [1, 2] and Na 3 Bi [3,4]. By breaking inversion symmetry (P) or time-reversal symmetry (T ), a Dirac point can be split into a pair of Weyl points. To break T , we can either apply an external magnetic field or use the spontaneous magnetic moment inside the material. For the latter case, the correlation between spontaneous magnetism and Weyl fermions has been studied in the AMnPn 2 (A = rare earth or alkali earth and Pn = Sb or Bi) system [5][6][7][8][9][10][11][12] and the half-Heusler compound GdPtBi [13,14]. Recently, CuMnAs was proposed to be an interesting material with non-trivial topology. CuMnAs has two polymorphs; the tetragonal (TET) CuMnAs, which crystalizes in the space group P 4/nmm, and the orthorhombic (ORT) CuMnAs crystalizing in the non-symmorphic P nma space group. The TET phase consists of alternating layers of edge-sharing CuAs 4 and MnAs 4 tetrahedra. It has been proposed to be a candidate with favourable applications in spintronics [18,19] and a topological metal-insulator transition driven by the Néel vector [17]. On the other hand, the ORT phase consists of a 3D network of edge-sharing CuAs 4 and MnAs 4 tetrahedra (Fig. 2(c)), where the Mn atoms form a 3D distorted honeycomb lattice (Fig. 2(d)). ORT CuMnAs was proposed to be an antiferromagnetic topological semimetal when the spin-orbit coupling is fully considered [15,17]. In such a system, two gapless points, named as coupled Weyl fermions, are robust if the combination of PT is * Corresponding author: nini@physics.ucla.edu reserved and the non-symmorphic screw symmetry S 2z is not broken. Thus, the anti-ferromagnetic ORT CuMnAs provides an ideal system to study the interplay between antiferromagnetism (AFM) and Dirac fermions [15]. In this paper, we will focus on the ORT CuMnAs. We experimentally determine its magnetic order, which breaks th...

show abstract

“…Beyond these intriguing features of AFM materials, the search for an AFM with desirable physical properties, e.g., high Néel temperature, spin–orbit, anisotropic phenomena, and highly conductive semiconducting, has been very intensive. The mostly explored AFM materials thus far in this regard are Mn‐based alloys, such as CuMnAs and Mn 2 Au, and B2‐ordered FeRh alloys . The latter exhibit various intriguing physical phenomena, including a magnetic phase transition from the AFM to the FM upon heating above room temperature and room temperature bistable AFM formation .…”

Section: Introductionmentioning

confidence: 99%

“…More recently, the FeRh thin films have been identified to exhibit even rich emergent phenomena such as thermal‐ and electric‐field controls of magnetic phase transition and magnetization reversal at the AFM–FM transition . The high Néel temperature and strong spin–orbit coupling (SOC) make the former class of AFM materials ideal candidates for antiferromagnet spintronics …”

Section: Introductionmentioning

confidence: 99%

Itinerant Semiconducting Antiferromagnetism in Metastable V₃Ga

Bao

Zhu

et al. 2019

Physica Rapid Research Ltrs

View full text Add to dashboard Cite

Herein, a metastable phase of β‐W type V3Ga is identified to exhibit an itinerant semiconducting antiferromagnetism. Density functional theory plus Hubbard U (DFT+U) calculations predict the β‐W type structure as a possible metastable phase, although energetically less favorable than the previously known D03 phase, which is successfully synthesized with good crystallinity by alternating evaporation method with postannealing process rather than traditional coevaporation method. Such a metastable β‐W phase results in an antiferromagnetic (AFM) order up to at least 500 K and highly conductive semiconducting behavior. The antiferromagnetism in the β‐W type V3Ga can be understood in terms of strong Coulomb repulsion and Hund's rule coupling between the nearest neighbor V 3d orbital states and their covalent bonding with the Ga 4p orbitals. These results are further verified by an exchange bias phenomenon revealed in antiferro/ferromagnet hybrid heterostructure of V3Ga and Fe films, where the strong hybridization between Fe 3d and V 3d orbital states at the interface gives rise to the robust perpendicular magnetic anisotropy therein. Herein, a novel route is used to prepare an AFM semiconductor material for antiferromagnet spintronics.

show abstract

Antiferromagnetic structure in tetragonal CuMnAs thin films

Cited by 85 publications

References 23 publications

Imaging Current-Induced Switching of Antiferromagnetic Domains in CuMnAs

Imaging Current-Induced Switching of Antiferromagnetic Domains in CuMnAs

Magnetic order induces symmetry breaking in the single-crystalline orthorhombic CuMnAs semimetal

Itinerant Semiconducting Antiferromagnetism in Metastable V₃Ga

Contact Info

Product

Resources

About

Antiferromagnetic structure in tetragonal CuMnAs thin films

Cited by 85 publications

References 23 publications

Imaging Current-Induced Switching of Antiferromagnetic Domains in CuMnAs

Imaging Current-Induced Switching of Antiferromagnetic Domains in CuMnAs

Magnetic order induces symmetry breaking in the single-crystalline orthorhombic CuMnAs semimetal

Itinerant Semiconducting Antiferromagnetism in Metastable V3Ga

Contact Info

Product

Resources

About

Itinerant Semiconducting Antiferromagnetism in Metastable V₃Ga