Electronic States and Magnetic Coupling in Fe/Fe3O4 Junctions

2011 ◽  
Vol 1292 ◽  
Author(s):  
J. Inoue ◽  
T. Kida ◽  
S. Honda ◽  
H. Itoh ◽  
H. Yanagihara ◽  
...  
Keyword(s):  
Exchange Coupling ◽  
Magnetic Moments ◽  
Magnetic Coupling ◽  
Exchange Interactions ◽  
Coupling Energy ◽  
Local Moments ◽  
Potential Applicability ◽  
Atomic Exchange ◽  
Magnetic States ◽  
Fe Ions

ABSTRACTExchange coupling observed recently in Fe/ Fe3O4 (001) junctions shows comparable intensity to that in Co/Ru/Co trilayers, and has potential applicability to spintronics devices. To clarify the mechanism of the exchange coupling, electronic and magnetic states of Fe/ Fe3O4 junctions are calculated in the first principles method by assuming four junction structures of bcc Fe and Fe3O4 layers. It is shown that the local moments of bcc Fe atoms at the interface increase, but those of Fe ions at the interface of Fe3O4 layer decrease. The total energy of the junctions is plotted as a function of distance between Fe and Fe3O4 layers. Calculated results of the coupling energy between Fe and Fe3O4 layers, however, are larger than experimental ones by two orders of magnitude, and they correspond to inter-atomic exchange interactions at the interface. In order to explain the experimental results, we propose a mechanism of exchange coupling mediated by impurity-like states of interfacial Fe atoms which possess reversed magnetic moments in bcc Fe layer. Frustration effects in exchange coupling between Fe and Fe3O4 layers are also discussed.

AB INITIO CALCULATION OF MAGNETIC MOMENTS, HYPERFINE FIELDS, MAGNETIC ANISOTROPY AND EXCHANGE INTERACTIONS IN RARE-EARTH INTERMETALLICS

1993 ◽  
Vol 07 (01n03) ◽  
pp. 710-715 ◽  
Author(s):  
K. HUMMLER ◽  
M. LIEBS ◽  
T. BEUERLE ◽  
M. FÄHNLE
Keyword(s):  
Rare Earth ◽  
Magnetic Anisotropy ◽  
Exchange Coupling ◽  
Magnetic Moments ◽  
Exchange Interactions ◽  
Orbital Method ◽  
Local Spin Density Approximation ◽  
Hyperfine Fields ◽  
Atomic Sphere ◽  
Sphere Approximation

The intrinsic magnetic properties of R2Fe14B (R=Pr, Nd, Sm, Gd, Tb, Dy, Ho, Er, Tm, Yb) are calculated from first principles within the local-spin-density approximation and the linear-muffin-tin-orbital method in atomic-sphere approximation. The total magnetization is in excellent agreement with experimental data. The local magnetic moments of the crystallographically inequivalent Fe sites appear to be not proportional to the local hyperfine fields. It is shown that the rare-earth contribution to the magnetic anisotropy may be qualitatively related to the electrostatic interaction of the aspherical 4f charge density with the crystal field. The effective intersublattice exchange coupling is evaluated from the change of the total energy upon 4f spin reversion.

Effect of Fe substitution on structure and exchange interactions within and between the sublattices of frustrated CoCr2O4

2020 ◽  
Vol 22 (48) ◽  
pp. 28222-28229
Author(s):  
Canglong Li ◽  
Chunlei Wang ◽  
Qiankun Lei ◽  
Godfrey Okumu Barasa ◽  
Qingshan Fu ◽  
...  
Keyword(s):  
Magnetic Coupling ◽  
Exchange Interactions ◽  
Geometrically Frustrated ◽  
High Interest ◽  
Points Of View ◽  
Magnetic States ◽  
Fe Substitution

Obtaining tunable magnetic states in geometrically frustrated multiferroic compound CoCr2O4 by tuning the sublattice magnetic coupling is indeed of high interest from the fundamental and applied points of view.

Electronic and magnetic states of Fe ions in the Co2FeBO5

2021 ◽  
Author(s):  
Natalia Kazak ◽  
Yurii V. Knyazev ◽  
Vyacheslav Zhandun ◽  
Juan Bartolomé ◽  
Ana Arauzo ◽  
...  
Keyword(s):  
Mössbauer Spectroscopy ◽  
Room Temperature ◽  
Mössbauer Spectra ◽  
Mossbauer Spectroscopy ◽  
57Fe Mössbauer Spectroscopy ◽  
57Fe Mössbauer ◽  
Mossbauer Spectra ◽  
57Fe Mossbauer Spectroscopy ◽  
Magnetic States ◽  
Fe Ions

The ludwigite Co2FeBO5 has been studied experimentally using 57Fe Mössbauer spectroscopy and theoretically by means of the DFT+GGA calculations. The room-temperature Mössbauer spectra are composed of four quadrupole doublets corresponding...

“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.

scholarly journals Large magnetic moments and anomalous exchange coupling in As-doped Mn clusters

2006 ◽  
Vol 73 (7) ◽  
Author(s):  
Mukul Kabir ◽  
D. G. Kanhere ◽  
Abhijit Mookerjee
Keyword(s):  
Exchange Coupling ◽  
Magnetic Moments

scholarly journals Control of the noncollinear interlayer exchange coupling

2020 ◽  
Vol 6 (48) ◽  
pp. eabd8861
Author(s):  
Zachary R. Nunn ◽  
Claas Abert ◽  
Dieter Suess ◽  
Erol Girt
Keyword(s):  
Exchange Coupling ◽  
Magnetic Moments ◽  
Interlayer Exchange Coupling ◽  
Magnetic Structures ◽  
Spintronic Devices ◽  
Spacer Layer ◽  
Ferromagnetic Layers ◽  
Almost All ◽  
Interlayer Exchange ◽  
Coupling Angle

Interlayer exchange coupling in transition metal multilayers has been intensively studied for more than three decades and is incorporated into almost all spintronic devices. With the current spacer layers, only collinear magnetic alignment can be reliably achieved; however, controlling the coupling angle has the potential to markedly expand the use of interlayer exchange coupling. Here, we show that the coupling angle between the magnetic moments of two ferromagnetic layers can be precisely controlled by inserting a specially designed magnetic metallic spacer layer between them. The coupling angle is controlled solely by the composition of the spacer layer. Moreover, the biquadratic coupling strength, responsible for noncollinear alignment, is larger than that of current materials. These properties allow for the fabrication and study of not yet realized magnetic structures that have the potential to improve existing spintronic devices.

Low temperature frequency dependence of the electron spin resonance absorption in heavily phosphorus-doped silicon

1970 ◽  
Vol 48 (24) ◽  
pp. 2930-2936 ◽  
Author(s):  
F. T. Hedgcock ◽  
T. W. Raudorf
Keyword(s):  
Electron Spin Resonance ◽  
Electron Spin ◽  
Magnetic Moments ◽  
Charge Carriers ◽  
Mobile Charge ◽  
Local Moments ◽  
Spin Resonance ◽  
Doped Silicon ◽  
Pauli Paramagnetism ◽  
Phosphorus Doped

Electron spin resonance (ESR) measurements have been made on a phosphorus-doped silicon specimen (n = 1.38 × 1019/cc) in the liquid helium temperature range. A single line with a g factor of approximately 2 was observed for resonant magnetic fields of 540, 3230, and 12 590 G at 1517, 9010, and 35 200 MHz respectively. The experimentally determined magnetization is compared with the magnetizations expected from the following sources: (a) un-ionized charge carriers or local magnetic moments obeying a Curie law, (b) mobile carriers experiencing an exchange interaction with local magnetic moments, and (c) mobile charge carriers showing only Pauli paramagnetism. The magnetization derived from the ESR data exhibits a linear dependence with magnetic field and no temperature dependence. This is consistent with the Pauli paramagnetism expected for mobile charge carriers in the absence of any interaction with local moments.

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