“Magnetic Exchange Interactions in Fe/TbFe Bilayers”

1987 ◽  
Vol 103 ◽  
Author(s):  
E. E. Marinero ◽  
G. S. Sprokel ◽  
H. Notarys
Keyword(s):  
Exchange Coupling ◽  
Azimuthal Angle ◽  
Depth Profiling ◽  
Ferromagnetic Layer ◽  
Exchange Interactions ◽  
Magnetic Characteristics ◽  
Magnetic Exchange ◽  
Kerr Rotation ◽  
Composition And Structure ◽  
Magnetic Exchange Coupling

ABSTRACTWe report on magnetic exchange coupling phenomena between Fe and TbFe thin films. The structures are grown utilizing D.C. magnetron sputtering from separate Tb and Fe targets and their magnetic characteristics are measured utilizing VSM and Longitudinal Kerr Rotation. In addition, Auger depth profiling and x-ray diffraction studies were conducted to study film composition and structure.Uniaxial alignment of the Fe moment in the plane of the substrate is revealed by the longitudinal Kerr measurements. The coercivity of the Fe layer varies from 19 Oe to 130 Oe depending on the azimuthal angle between the normal to the plane of the bilayer and the direction of the external field. The hysterisis loops vary in shape from rectangular in the alignment direction to S-shape in the direction orthogonal to this direction.These effects are discussed in terms of magnetic exchange coupling interactions between the ferromagnetic layer and the ferrimagnetic alloy.

First Principle Investigations of Long-range Magnetic Exchange Interactions via Polyacene Coupler

2020 ◽  
Author(s):  
Prabhleen Kaur ◽  
Md. Ehesan Ali
Keyword(s):  
Wave Function ◽  
Long Range ◽  
Exchange Coupling ◽  
Exchange Interactions ◽  
Coupling Constants ◽  
Magnetic Exchange ◽  
Active Space ◽  
Exponential Increase ◽  
Magnetic Exchange Coupling ◽  
Benzene Rings

The polyacene tend to transition from closed-shell to open-shell singlet systems with increase in the number of linearly fused benzene rings thus, enriching it's electronic as well as magnetic properties. Here, we have probed the role of such a polyacene couplers in mediating the magnetic exchange coupling between nitroxy radicals. For this, magnetic exchange coupling constants (<i>2J</i>) are computed employing broken-symmetry approach within density functional theory (DFT) as well as symmetry-adopted wave function based multi-configuration approach. Within DFT approach, apart from most commonly used exchange-correlation functional (generalized gradient approximation (GGA), meta-GGA, and hybrid) constrained spin density (CDFT) and on-site Coulomb correlation corrected GGA+<i>U</i> functionals have also been used to evaluate the exchange coupling constants in the diradicals. All DFT based methods approximate an exponential increase in the coupling constant values with increase in the length of the coupler. This is indeed an unexpected observation with no experimental report available to such an outcome by DFT calculations. Therefore, the electronic structures for these diradical systems with the increase in number of benzene rings were looked upon thoroughly. The properties like increase in number of degenerate or quasi-degenerate molecular orbitals (MOs), the lowering in energy of low-lying excited states and the development of intrinsic radical character of the coupler add to the complexity in evaluation of <i>2J </i>values for such diradical systems with DFT approach. Consequently, wave function based multi-reference approach (CAASCF/NEVPT2) has been adopted. The active space has been limited to π-orbitals which are found to play an important role in the magnetic exchange interactions. With increase in the coupler size, the active space even with only π obitals would increase enormously which could not be taken into account even in the CASSCF study. The limited active space calculations also indicate quite strong exchange interaction, thus in principle, supporting the DFT observations of long-range magnetic exchange interactions but not an exponential increase in <i>2J</i> with length of couplers.

Structural stability and magnetic-exchange coupling in Mn-doped monolayer/bilayer MoS2

2018 ◽  
Vol 20 (1) ◽  
pp. 553-561 ◽  
Author(s):  
Qinglong Fang ◽  
Xumei Zhao ◽  
Yuhong Huang ◽  
Kewei Xu ◽  
Tai Min ◽  
...  
Keyword(s):  
Transition Metal ◽  
Exchange Coupling ◽  
Transition Metal Dichalcogenides ◽  
Magnetic Characteristics ◽  
Two Dimensional ◽  
Magnetic Exchange ◽  
Magnetic Exchange Coupling ◽  
Potential Applications ◽  
Metal Dichalcogenides ◽  
Mn Doped

Ferromagnetic (FM) two-dimensional (2D) transition metal dichalcogenides (TMDs) have potential applications in modern electronics and spintronics and doping of TMDs with transition metals can enhance the magnetic characteristics.

Scanning Electron Microscopy With Polarization Analysis (Sempa) Investigations Of Multilayer Magnetism

1999 ◽  
Vol 5 (S2) ◽  
pp. 40-41
Author(s):  
J. Unguris ◽  
R. J. Celotta ◽  
D. T. Pierce
Keyword(s):  
Data Storage ◽  
Exchange Coupling ◽  
Film Growth ◽  
Depth Profiling ◽  
Thin Film Growth ◽  
Ion Milling ◽  
Magnetic Exchange ◽  
Surface Sensitivity ◽  
Surface Analysis Techniques ◽  
Magnetic Exchange Coupling

Mulitlayers consisting of various combinations of 1-10 nm thick ferromagnetic, antiferromagnetic and nonmagnetic films have numerous applications in magnetic recording, non-volatile data storage, and sensor technologies. One key aspect to understanding how these devices work is being able to image their magnetic structure. SEMPA is well suited for this job, because of its surface sensitivity and compatibility with thin film growth and surface analysis techniques. This talk will review the SEMPA technique and describe thep use of SEMPA in two examples; one in which the magnetization is imaged while growing a multilayer, and another which examines the magnetization while depth profiling a multilayer by ion milling.A SEMPA investigation of the magnetic exchange coupling in an Fe/Cr/Fe sandwich is shown in Figs. 1 and 2. A wedge shaped Cr interlayer was grown as shown in Fig. 1 in order to measure the Cr thickness dependence of the exchange coupling.

scholarly journals Magnetic exchange interactions in symmetric lanthanide dimetallics

2020 ◽  
Vol 7 (20) ◽  
pp. 3909-3918
Author(s):  
Marcus J. Giansiracusa ◽  
Susan Al-Badran ◽  
Andreas K. Kostopoulos ◽  
George F. S. Whitehead ◽  
Eric J. L. McInnes ◽  
...  
Keyword(s):  
Exchange Coupling ◽  
Lanthanide Complexes ◽  
Exchange Interactions ◽  
Epr Spectra ◽  
Magnetic Exchange ◽  
Magnetic Exchange Coupling

Multi-frequency EPR spectra and CASSCF-SO calculations on two symmetric homo-dimetallic lanthanide complexes are used to determine the magnetic exchange coupling in the low-lying states.

A novel and facile route to in-situ formation of composites with dual coupling interactions for considerable millimeter-wave absorption performance

2021 ◽  
Author(s):  
Chuyang Liu ◽  
Tao Jiang ◽  
Tian Gao ◽  
Guangxian Xia ◽  
Yufan Cao ◽  
...  
Keyword(s):  
Millimeter Wave ◽  
Exchange Coupling ◽  
Ferromagnetic Coupling ◽  
Soft Magnetic ◽  
Magnetic Exchange ◽  
Magnetic Exchange Coupling ◽  
Absorption Performance ◽  
In Situ Formation ◽  
Facile Route

It is well known that both hard/soft magnetic exchange-coupling and ferroelectric-ferromagnetic coupling could facilitate the microwave absorption behavior. Herein, we propose the BaZrxFe12-xO19/Fe3O4/BaZrO3 composites to integrate the advantages of the...

scholarly journals Transferrable property relationships between magnetic exchange coupling and molecular conductance

2020 ◽  
Vol 11 (42) ◽  
pp. 11425-11434
Author(s):  
Martin L. Kirk ◽  
Ranjana Dangi ◽  
Diana Habel-Rodriguez ◽  
Jing Yang ◽  
David A. Shultz ◽  
...  
Keyword(s):  
Exchange Coupling ◽  
Semiquinone Radical ◽  
Magnetic Exchange ◽  
Magnetic Exchange Coupling ◽  
Coupling Parameters ◽  
Molecular Conductance

Calculated conductance through Aun–S–Bridge–S–Aun constructs are compared to experimental magnetic exchange coupling parameters in TpCum,MeZn(SQ–Bridge–NN) complexes, where SQ = semiquinone radical and NN = nitronylnitroxide radical.

Magnetic exchange coupling in tetranuclear copper clusters of the type [Cu4(μ4O)Cl6−nBrnL4]

2001 ◽  
Vol 344 (3-4) ◽  
pp. 305-309 ◽  
Author(s):  
Roman Boča ◽  
L'ubor Dlháň ◽  
Darina Makáňová ◽  
Jerzi Mrozinski ◽  
Gregor Ondrejovič ◽  
...  
Keyword(s):  
Exchange Coupling ◽  
Magnetic Exchange ◽  
Copper Clusters ◽  
Magnetic Exchange Coupling

scholarly journals Magnetic exchange-coupling effects in asymmetric trilayer structures of MBE-grown Co/Cr/Fe

1996 ◽  
Vol 53 (17) ◽  
pp. 11613-11620 ◽  
Author(s):  
Katharina Theis-Bröhl ◽  
Rainer Scheidt ◽  
Thomas Zeidler ◽  
Frank Schreiber ◽  
Hartmut Zabel ◽  
...  
Keyword(s):  
Exchange Coupling ◽  
Coupling Effects ◽  
Magnetic Exchange ◽  
Magnetic Exchange Coupling

Magnetostructural relationship for μ2-phenoxido bridged ferric dimers

2017 ◽  
Vol 46 (13) ◽  
pp. 4317-4324 ◽  
Author(s):  
Fei Yu ◽  
Zi-Heng Cao ◽  
Jing-Yuan Ge ◽  
Yi-Chen Sun ◽  
Zhong-Wen Ouyang ◽  
...  
Keyword(s):  
Dft Calculations ◽  
Exchange Coupling ◽  
Crossover Point ◽  
Magnetic Exchange ◽  
Structural Correlation ◽  
Magnetic Exchange Coupling ◽  
Epr Measurements

The magneto-structural correlation between μ2-phenoxido bridged iron(iii) complexes are studied by structural analyses, magnetic, HF-EPR measurements, and DFT calculations. The magnetic exchange coupling is governed by the Fe–O–Fe angle and the crossover point from AF to F interactions is θ at 97.83°.

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