scholarly journals Faster chiral versus collinear magnetic order recovery after optical excitation revealed by femtosecond XUV scattering

2020 ◽  
Vol 11 (1) ◽  
Author(s):  
Nico Kerber ◽  
Dmitriy Ksenzov ◽  
Frank Freimuth ◽  
Flavio Capotondi ◽  
Emanuele Pedersoli ◽  
...  
Keyword(s):  
Domain Walls ◽  
Magnetic Order ◽  
Optical Excitation ◽  
Magnetic Scattering ◽  
Ultrafast Dynamics ◽  
Spin Structures ◽  
X Ray ◽  
Probe Experiment ◽  
Moriya Interaction ◽  
Chiral Order

AbstractWhile chiral spin structures stabilized by Dzyaloshinskii-Moriya interaction (DMI) are candidates as novel information carriers, their dynamics on the fs-ps timescale is little known. Since with the bulk Heisenberg exchange and the interfacial DMI two distinct exchange mechanisms are at play, the ultrafast dynamics of the chiral order needs to be ascertained and compared to the dynamics of the conventional collinear order. Using an XUV free-electron laser we determine the fs-ps temporal evolution of the chiral order in domain walls in a magnetic thin film sample by an IR pump - X-ray magnetic scattering probe experiment. Upon demagnetization we observe that the dichroic (CL-CR) signal connected with the chiral order correlator mzmx in the domain walls recovers significantly faster than the (CL + CR) sum signal representing the average collinear domain magnetization mz2 + mx2. We explore possible explanations based on spin structure dynamics and reduced transversal magnetization fluctuations inside the domain walls and find that the latter can explain the experimental data leading to different dynamics for collinear magnetic order and chiral magnetic order.

Observation of magnetic order in multiferroicSmMn2O5studied by resonant x-ray magnetic scattering

2016 ◽  
Vol 93 (6) ◽  
Author(s):  
Y. Ishii ◽  
S. Horio ◽  
M. Mitarashi ◽  
T. Sakakura ◽  
M. Fukunaga ◽  
...  
Keyword(s):  
Magnetic Order ◽  
Magnetic Scattering ◽  
X Ray

Magnetic order of LiCu2O2 studied by resonant soft x-ray magnetic scattering

2008 ◽  
Vol 147 (5-6) ◽  
pp. 234-237 ◽  
Author(s):  
S.W. Huang ◽  
D.J. Huang ◽  
J. Okamoto ◽  
W.B. Wu ◽  
C.T. Chen ◽  
...  
Keyword(s):  
Magnetic Order ◽  
Magnetic Scattering ◽  
X Ray

Magnetic Scattering in High-Energy Electron Diffraction

1990 ◽  
Vol 48 (2) ◽  
pp. 534-535
Author(s):  
David Bird ◽  
John Barnard
Keyword(s):  
Magnetic Structure ◽  
Magnetic Order ◽  
Structural Phase ◽  
High Energy ◽  
Dark Field ◽  
Magnetic Scattering ◽  
X Ray ◽  
Lorentz Microscopy ◽  
Dark Field Imaging ◽  
Ferromagnetic Domains

Over the past 25 years or so, neutron diffraction has become the standard method of probing the internal magnetic structure of crystals. More recently, however, it has been found that x-ray magnetic scattering, although weak, can be observed using bright x-ray sources. The success of x-ray techniques leads one to wonder whether magnetic scattering might also be observed using electrons, and it is this question that is addressed here. Clearly, electrons are influenced by the internal magnetic fields of specimens_this is the basis of Lorentz microscopy of ferromagnetic domains. Here we examine scattering from more exotic forms of magnetic order, such as anti-ferromagnetism. The interesting point is that antiferromagnets have magnetic Bragg spots which appear between the basic lattice spots as the magnetic order sets in. Analysis of these spots forms the basis of neutron, and now x-ray, studies of magnetic structures. The extra ingredient that electrons might offer is that imaging in such spots could reveal the local magnetic structure including domains, dynamic effects etc., in just the same way that satellite dark-field imaging has contributed to studies of structural phase transitions.

scholarly journals A decade of multiferroic research: new concepts and materials

2014 ◽  
Vol 70 (a1) ◽  
pp. C15-C15
Author(s):  
Laurent Chapon
Keyword(s):  
Degrees Of Freedom ◽  
Magnetic Order ◽  
Magnetic Scattering ◽  
Coupling Mechanism ◽  
Type Ii ◽  
Magnetic Domains ◽  
X Ray ◽  
Range Magnetic Order ◽  
New Concepts ◽  
Long Range Magnetic Order

In the last 10 years, the surge of interest for multiferroics has allowed to identify several new classes of materials in which electric and magnetic degrees of freedom are highly coupled. In particular, in the so-called type II multiferroics, the onset of long range magnetic order induces ferroelectric polarization and the magnetic domains can be controlled by an electric field or conversely the direction of the polarization can be flopped by a magnetic field. I will review the most recent discovery in the field, and show how neutron and X-ray magnetic scattering provide a very detailed understanding of the magnetoelectric coupling mechanism.

scholarly journals The magnetic order of GdMn2Ge2studied by neutron diffraction and x-ray resonant magnetic scattering

2010 ◽  
Vol 22 (22) ◽  
pp. 226005 ◽  
Author(s):  
S A Granovsky ◽  
A Kreyssig ◽  
M Doerr ◽  
C Ritter ◽  
E Dudzik ◽  
...  
Keyword(s):  
Neutron Diffraction ◽  
Magnetic Order ◽  
Magnetic Scattering ◽  
X Ray

scholarly journals Magnetic order in GdBiPt studied by x-ray resonant magnetic scattering

2011 ◽  
Vol 84 (22) ◽  
Author(s):  
A. Kreyssig ◽  
M. G. Kim ◽  
J. W. Kim ◽  
D. K. Pratt ◽  
S. M. Sauerbrei ◽  
...  
Keyword(s):  
Magnetic Order ◽  
Magnetic Scattering ◽  
X Ray

scholarly journals Ultrafast time-evolution of chiral Néel magnetic domain walls probed by circular dichroism in x-ray resonant magnetic scattering.

2021 ◽  
Author(s):  
Cyril Lévéillé ◽  
Erick Burgos-Parra ◽  
Yanis Sassi ◽  
Fernando Ajejas ◽  
Valentin Chardonnet ◽  
...  
Keyword(s):  
Circular Dichroism ◽  
Optical Pumping ◽  
Domain Walls ◽  
Spin Current ◽  
Magnetic Domain ◽  
Magnetic Interactions ◽  
Magnetic Scattering ◽  
X Ray ◽  
Magnetic Domain Walls ◽  
Circular Dichroïsm

Abstract Non-collinear spin textures in ferromagnetic ultrathin films are attracting a renewed interest fueled by possible fine engineering of several magnetic interactions, notably the interfacial Dzyaloshinskii-Moriya interaction. This allows the stabilization of complex chiral spin textures such as chiral magnetic domain walls (DWs), spin spirals, and magnetic skyrmions. We report here on the ultrafast behavior of chiral DWs after optical pumping in perpendicularly magnetized asymmetric multilayers, probed using time-resolved circular dichroism in x-ray resonant magnetic scattering (CD-XRMS). We observe a picosecond transient reduction of the CD-XRMS, which is attributed to the spin current-induced coherent and incoherent torques within the continuously dependent spin texture of the DWs. We argue that a specific demagnetization of the inner structure of the DW induces a flow of spins from the interior of the neighboring magnetic domains. We identify this time-varying change of the DW texture shortly after the laser pulse as a distortion of the homochiral Néel shape toward a transient mixed Bloch-Néel-Bloch texture along a direction transverse to the DW.

scholarly journals Emergent long-range magnetic order in ultrathin (111)-oriented LaNiO3 films

2021 ◽  
Vol 6 (1) ◽  
Author(s):  
Margaret M. Kane ◽  
Arturas Vailionis ◽  
Lauren J. Riddiford ◽  
Apurva Mehta ◽  
Alpha T. N’Diaye ◽  
...  
Keyword(s):  
Long Range ◽  
Degrees Of Freedom ◽  
Magnetic Order ◽  
Magnetic Ordering ◽  
Anomalous Hall Effect ◽  
X Ray Diffraction ◽  
X Ray ◽  
Range Magnetic Order ◽  
Film Substrate ◽  
Long Range Magnetic Order

AbstractThe emergence of ferromagnetism in materials where the bulk phase does not show any magnetic order demonstrates that atomically precise films can stabilize distinct ground states and expands the phase space for the discovery of materials. Here, the emergence of long-range magnetic order is reported in ultrathin (111) LaNiO3 (LNO) films, where bulk LNO is paramagnetic, and the origins of this phase are explained. Transport and structural studies of LNO(111) films indicate that NiO6 octahedral distortions stabilize a magnetic insulating phase at the film/substrate interface and result in a thickness-dependent metal–insulator transition at t = 8 unit cells. Away from this interface, distortions relax and bulk-like conduction is regained. Synchrotron x-ray diffraction and dynamical x-ray diffraction simulations confirm a corresponding out-of-plane unit-cell expansion at the interface of all films. X-ray absorption spectroscopy reveals that distortion stabilizes an increased concentration of Ni2+ ions. Evidence of long-range magnetic order is found in anomalous Hall effect and magnetoresistance measurements, likely due to ferromagnetic superexchange interactions among Ni2+–Ni3+ ions. Together, these results indicate that long-range magnetic ordering and metallicity in LNO(111) films emerges from a balance among the spin, charge, lattice, and orbital degrees of freedom.

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