scholarly journals Ruderman–Kittel–Kasuya–Yosida-type interfacial Dzyaloshinskii–Moriya interaction in heavy metal/ferromagnet heterostructures

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Taehyun Kim ◽  
In Ho Cha ◽  
Yong Jin Kim ◽  
Gyu Won Kim ◽  
Andrey Stashkevich ◽  
...  
Keyword(s):  
Heavy Metal ◽  
Exchange Coupling ◽  
Spin Orbit Coupling ◽  
Conduction Electrons ◽  
Indirect Exchange ◽  
Metal Atoms ◽  
Technological Potential ◽  
Interfacial Modification ◽  
Coupling Phenomena ◽  
Moriya Interaction

AbstractThe manipulation of magnetization with interfacial modification using various spin-orbit coupling phenomena has been recently revisited due to its scientific and technological potential for next-generation memory devices. Herein, we experimentally and theoretically demonstrate the interfacial Dzyaloshinskii–Moriya interaction characteristics penetrating through a MgO dielectric layer inserted between the Pt and CoFeSiB. The inserted MgO layer seems to function as a chiral exchange interaction mediator of the interfacial Dzyaloshinskii–Moriya interaction from the heavy metal atoms to ferromagnet ones. The potential physical mechanism of the anti-symmetric exchange is based on the tunneling-like behavior of conduction electrons through the semi-conductor-like ultrathin MgO. Such behavior can be correlated with the oscillations of the indirect exchange coupling of the Ruderman–Kittel–Kasuya–Yosida type. From the theoretical demonstration, we could provide approximate estimation and show qualitative trends peculiar to the system under investigation.

scholarly journals Dzyaloshinskii–Moriya interaction in noncentrosymmetric superlattices

2021 ◽  
Vol 7 (1) ◽  
Author(s):  
Woo Seung Ham ◽  
Abdul-Muizz Pradipto ◽  
Kay Yakushiji ◽  
Kwangsu Kim ◽  
Sonny H. Rhim ◽  
...  
Keyword(s):  
Heavy Metal ◽  
Degrees Of Freedom ◽  
Orbit Coupling ◽  
Inversion Symmetry ◽  
Spin Orbit Coupling ◽  
Spin Orbit ◽  
Band Formation ◽  
Research Activities ◽  
Moriya Interaction

AbstractDzyaloshinskii–Moriya interaction (DMI) is considered as one of the most important energies for specific chiral textures such as magnetic skyrmions. The keys of generating DMI are the absence of structural inversion symmetry and exchange energy with spin–orbit coupling. Therefore, a vast majority of research activities about DMI are mainly limited to heavy metal/ferromagnet bilayer systems, only focusing on their interfaces. Here, we report an asymmetric band formation in a superlattices (SL) which arises from inversion symmetry breaking in stacking order of atomic layers, implying the role of bulk-like contribution. Such bulk DMI is more than 300% larger than simple sum of interfacial contribution. Moreover, the asymmetric band is largely affected by strong spin–orbit coupling, showing crucial role of a heavy metal even in the non-interfacial origin of DMI. Our work provides more degrees of freedom to design chiral magnets for spintronics applications.

scholarly journals Giant Dzyaloshinskii-Moriya interaction in Rashba superlattices

2020 ◽  
Author(s):  
Woo-Seung Ham ◽  
Abdul-Muizz Pradipto ◽  
Kay Yakushiji ◽  
Kwangsu Kim ◽  
Sonny Rhim ◽  
...  
Keyword(s):  
Heavy Metal ◽  
Material Design ◽  
Orbit Coupling ◽  
Inversion Symmetry ◽  
Spin Orbit Coupling ◽  
Spin Orbit ◽  
Band Formation ◽  
Stacking Order ◽  
Magnetic Skyrmions ◽  
Moriya Interaction

Abstract Dzyaloshinskii-Moriya interaction (DMI) is considered as one of the most important energy for specific chiral texture such as magnetic skyrmions. The key of generating DMI is absence of structural inversion symmetry and exchange energy with spin-orbit coupling. Therefore, a vast majority of researches about DMI is mainly limited to heavy metal/ferromagnet bilayer systems, only focusing on their interfaces. Here, we report that asymmetric band formation in an artificial superlattice arises from inversion symmetry breaking in stacking order of atomic layers, resulting in bulk DMI. Such bulk DMI is more than 300% larger than simple sum of interfacial contribution. Moreover, the asymmetric band is largely affected by strong spin-orbit coupling, showing crucial role of a heavy metal even in the non-interfacial origin of DMI. Such Rashba superlattices can be a new class of material design for spintronics applications.

scholarly journals Spin–Orbit Effects in CoFeB/MgO Heterostructures with Heavy Metal Underlayers

SPIN ◽  
2016 ◽  
Vol 06 (02) ◽  
pp. 1640002 ◽  
Author(s):  
Jacob Torrejon ◽  
Junyeon Kim ◽  
Jaivardhan Sinha ◽  
Masamitsu Hayashi
Keyword(s):  
Heavy Metal ◽  
Transition Metals ◽  
Magnetic Anisotropy ◽  
Metal Layer ◽  
Perpendicular Magnetic Anisotropy ◽  
Orbit Coupling ◽  
Spin Orbit Coupling ◽  
Spin Orbit ◽  
Moriya Interaction ◽  
Strong Spin

We study effects originating from the strong spin–orbit coupling in CoFeB/MgO heterostructures with heavy metal (HM) underlayers. The perpendicular magnetic anisotropy at the CoFeB/MgO interface, the spin Hall angle of the heavy metal layer, current induced torques and the Dzyaloshinskii–Moriya interaction at the HM/CoFeB interfaces are studied for films in which the early 5[Formula: see text] transition metals are used as the HM underlayer. We show how the choice of the HM layer influences these intricate spin–orbit effects that emerge within the bulk and at interfaces of the heterostructures.

A synchrotron X-ray study of the electron density in C-type rare earth oxides

1996 ◽  
Vol 52 (3) ◽  
pp. 414-422 ◽  
Author(s):  
E. N. Maslen ◽  
V. A. Streltsov ◽  
N. Ishizawa
Keyword(s):  
Heavy Metal ◽  
Rare Earth ◽  
Electron Density ◽  
Approximate Symmetry ◽  
Data Set ◽  
X Ray ◽  
Metal Atoms ◽  
Structure Factors ◽  
Deformation Electron Density ◽  
Synthetic Crystals

Structure factors for small synthetic crystals of the C-type rare earth (RE) sesquioxides Y2O3, Dy2O3 and Ho2O3 were measured with focused λ = 0.7000 (2) Å, synchrotron X-radiation, and for Ho2O3 were re-measured with an MoKα (λ = 0.71073 Å) source. Approximate symmetry in the deformation electron density (Δρ) around a RE atom with pseudo-octahedral O coordination matches the cation geometry. Interactions between heavy metal atoms have a pronounced effect on the Δρ map. The electron-density symmetry around a second RE atom is also perturbed significantly by cation–anion interactions. The compounds magnetic properties reflect this complexity. Space group Ia{\bar 3}, cubic, Z = 16, T = 293 K: Y2O3, Mr = 225.82, a = 10.5981 (7) Å, V = 1190.4 (2) Å3, Dx = 5.040 Mg m−3, μ 0.7 = 37.01 mm−1, F(000) = 1632, R = 0.067, wR = 0.067, S = 9.0 (2) for 1098 unique reflections; Dy2O3, Mr = 373.00, a = 10.6706 (7) Å, V = 1215.0 (2) Å3, Dx = 8.156 Mg m−3, μ 0.7 = 44.84 mm−1, F(000) = 2496, R = 0.056, wR = 0.051, S = 7.5 (2) for 1113 unique reflections; Ho2O3, Mr = 377.86, a = 10.606 (2) Å, V = 1193.0 (7) Å3, Dx = 8.415 Mg m−3, μ 0.7 = 48.51 mm−1 F(000) = 2528, R = 0.072, wR = 0.045, S = 9.2 (2) for 1098 unique reflections of the synchrotron data set.

scholarly journals Correction: Towards accurate and precise positions of hydrogen atoms bonded to heavy metal atoms

2021 ◽  
Author(s):  
Magdalena Woińska ◽  
Michał L. Chodkiewicz ◽  
Krzysztof Woźniak
Keyword(s):  
Heavy Metal ◽  
Hydrogen Atoms ◽  
Metal Atoms

Correction for ‘Towards accurate and precise positions of hydrogen atoms bonded to heavy metal atoms’ by Magdalena Woińska et al., Chem. Commun., 2021, 57, 3652–3655, DOI: 10.1039/D0CC07661A.

scholarly journals Large Dzyaloshinskii-Moriya interaction induced by chemisorbed oxygen on a ferromagnet surface

2020 ◽  
Vol 6 (33) ◽  
pp. eaba4924 ◽  
Author(s):  
Gong Chen ◽  
Arantzazu Mascaraque ◽  
Hongying Jia ◽  
Bernd Zimmermann ◽  
MacCallum Robertson ◽  
...  
Keyword(s):  
Room Temperature ◽  
Ferromagnetic Layer ◽  
Spin Orbit Coupling ◽  
Winding Number ◽  
Large Magnitude ◽  
Chemisorbed Oxygen ◽  
Magnetic Layers ◽  
Oxygen Coverage ◽  
Opening Up ◽  
Moriya Interaction

The Dzyaloshinskii-Moriya interaction (DMI) is an antisymmetric exchange interaction that stabilizes chiral spin textures. It is induced by inversion symmetry breaking in noncentrosymmetric lattices or at interfaces. Recently, interfacial DMI has been found in magnetic layers adjacent to transition metals due to the spin-orbit coupling and at interfaces with graphene due to the Rashba effect. We report direct observation of strong DMI induced by chemisorption of oxygen on a ferromagnetic layer at room temperature. The sign of this DMI and its unexpectedly large magnitude—despite the low atomic number of oxygen—are derived by examining the oxygen coverage–dependent evolution of magnetic chirality. We find that DMI at the oxygen/ferromagnet interface is comparable to those at ferromagnet/transition metal interfaces; it has enabled direct tailoring of skyrmion’s winding number at room temperature via oxygen chemisorption. This result extends the understanding of the DMI, opening up opportunities for the chemisorption-related design of spin-orbitronic devices.

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