LARGE EFFECTS OF MAGNETIC FIELD ON JOSEPHSON CURRENTS THROUGH ANTIFERROMAGNETIC BARRIERS

2002 ◽  
Vol 16 (20n22) ◽  
pp. 3316-3316
Author(s):  
L. P. GOR'KOV ◽  
V. Z. KRESIN
Keyword(s):  
Magnetic Field ◽  
Detrimental Effect ◽  
Magnetic Moments ◽  
Mixed Valence ◽  
Josephson Current ◽  
Current Amplitude ◽  
Weak Links ◽  
Ferromagnetic Domains ◽  
Ferromagnetic Layers ◽  
Mixed Valence Manganites

Ferromagnetism being known to have a detrimental effect on superconductivity, we consider the Josephson current amplitude for junctions built up of antiferromagnetic metallic weak links. It is assumed that the latter consist of ferromagnetic layers with magnetizations aligned alternatively along perpendicular-to-the-layers direction. Currents between two superconducting electrodes flow along the layers. Such antiferromagnetic structure realizes itself in mixed valence manganites (the so-called A-phase), in an array of parallel ferromagnetic domains, or even in artificial GMR heterostructures. It is shown that even minor canting of magnetic moments in the presence of magnetic fields causes remarkable oscillations in the value of the Josephson current amplitude.

scholarly journals Controllable two- vs three-state magnetization switching in single-layer epitaxial Pd1-xFex films and epitaxial Pd0.92Fe0.08/Ag/Pd0.96Fe0.04 heterostructure

2021 ◽  
Author(s):  
Igor Yanilkin ◽  
Amir Gumarov ◽  
Gulnaz Gizzatullina ◽  
Roman Yusupov ◽  
Lenar Tagirov
Keyword(s):  
Magnetic Field ◽  
Low Temperature ◽  
Applied Magnetic Field ◽  
Magnetization Reversal ◽  
Easy Axis ◽  
Magnetic State ◽  
Magnetic Moments ◽  
Single Layer ◽  
Wide Range ◽  
Ferromagnetic Layers

We have investigated the low-temperature magnetoresistive properties of a thin epitaxial Pd0.92Fe0.08 film at different directions of the current and the applied magnetic field. The obtained experimental results are well described within an assumption of a single-domain magnetic state of the film. In a wide range of the appled field directions, the magnetization reversal proceeds in two steps via the intermediate easy axis. An epitaxial heterostructure of two magnetically separated ferromagnetic layers, Pd0.92Fe0.08/Ag/Pd0.96Fe0.04, was synthesized and studied with the dc magnetometry. Its magnetic configuration diagram has been constructed and the conditions have been determined for a controllable switching between stable parallel, orthogonal, and antiparallel arrangements of magnetic moments of the layers.

Properties of the Colossal Magnetoresistivity and its Field Sensitivity of the Mixed-Valence Manganites Nd0.52Sr0.48MnO3

2010 ◽  
Vol 663-665 ◽  
pp. 890-893
Author(s):  
Shi Wei Ren ◽  
Tian Shan Liu ◽  
Zhan He Li
Keyword(s):  
Magnetic Field ◽  
Rare Earth ◽  
Mixed Valence ◽  
Sudden Change ◽  
Ferromagnetic Transition ◽  
Physical Origin ◽  
Magnetic Phases ◽  
Field Sensitivity ◽  
Mixed Valence Manganites ◽  
Magnetically Aligned

In this paper, according to the model proposed by Wagner et al., the properties of the magnetically aligned clusters in rare earth manganite Nd0.52Sr0.48MnO3 film are investigated. As we all have known, even at the same temperature and in the same external magnetic field the colossal magnetoresistivity (CMR) effects of different manganites are different. Through imitating the variation of the magnetoresistance (MR) with respect to some physics parameters, the built-in factors that can influence the value of MR and the field sensitivity are analyzed. The investigations show that the CMR effects, to some extent, can be governed by the size of the magnetically aligned clusters. In addition, through analyzing the different magnetoresistance scaling in different magnetic phases it is found that with the paramagnetic-ferromagnetic transition a sudden change in the size of the magnetically aligned clusters occurs, the physical origin of which are explored.

scholarly journals Electron Localization in Mixed-Valence Manganites

1995 ◽  
Vol 75 (21) ◽  
pp. 3910-3913 ◽  
Author(s):  
J. M. D. Coey ◽  
M. Viret ◽  
L. Ranno ◽  
K. Ounadjela
Keyword(s):  
Mixed Valence ◽  
Electron Localization ◽  
Mixed Valence Manganites

scholarly journals Reducing the influence of interference of spacecraft magnetic field on magnetic measurements

2019 ◽  
Vol 18 (2) ◽  
pp. 33-40
Author(s):  
A. M. Beznyakov ◽  
I. S. Guriev ◽  
I. P. Ryzhova
Keyword(s):  
Magnetic Field ◽  
Magnetic Fields ◽  
Support Systems ◽  
Magnetic Measurements ◽  
Magnetic Moments ◽  
Navigation Support

The article presents constructive ways of reducing the influence of magnetic interference from spacecraft, due to its own magnetic fields, on the on-board magnetic measurements, as well as reducing the resulting magnetic moments. Well-known methods of removing magnetometer sensors from the locations of the most powerful sources of magnetic fields of a spacecraft, in particular, using extendable booms, are considered. In addition, methods for reducing the influence of spacecraft self- magnetic fields on the onboard magnetometric navigation support systems using known closed and proposed hemispherical ferromagnetic shields are considered

scholarly journals Spin transport and spin dynamics in antiferromagnets

2021 ◽  
Author(s):  
◽  
Geert Hoogeboom
Keyword(s):  
Magnetic Field ◽  
Heavy Metal ◽  
Spin Transport ◽  
Spin Dynamics ◽  
Magnetic Moments ◽  
Spin Current ◽  
Active Role ◽  
Metal Films ◽  
Alternating Direction ◽  
High Processing

Ferromagnets (FMs) have been a key ingredient in information technology because it is easy to manipulate and read out the magnetization. Antiferromagnets (AFMs) have magnetic moments with alternating direction resulting in negligible magnetization. This gives them high processing and device downscaling features, but this also makes it challenging to manipulate and interact with the AFM order. This thesis studies this interaction with antiferromagnets. NiO AFM order has been read out by electrically injecting spin current via the spin Hall effect in thin heavy metal films. In DyFeO3, both Dy and Fe magnetic moments, their excitation and interaction have been probed. A magnetic field lifts the degeneracy of magnetic excitations with opposite magnon spin, allowing a spin current to be detected nonlocally. The AFM order and the generation of spin current can easily be controlled by an adjacent FM. Thereby, we show that AFMs have the potential to play an active role in spintronics.

Infinite solitons in ferromagnetic materials with an internal magnetic field

2021 ◽  
pp. 2150413
Author(s):  
Hamdy I. Abdel-Gawad
Keyword(s):  
Magnetic Field ◽  
External Magnetic Field ◽  
External Field ◽  
Model Equation ◽  
Graphical Representation ◽  
Magnetic Moments ◽  
Soliton Solutions ◽  
Internal Magnetic Field ◽  
Multiple Soliton Solutions ◽  
The Magnetic Field

The ferromagnetism induced by an external magnetic field (EMF), in (3+1) dimensions, is governed by Kraenkel–Manna–Merle system (KMMS). A (1+1) dimension model equation was derived in the literature. The magnetic moments are parallel to the magnetic field in ferromagnetism as they are aligning in the same direction of the external field. Here, it is shown that the KMMS supports the presence of internal magnetic field. This may be argued to medium characteristics. The objective of this work is to mind multiple soliton solutions, which are obtained via the generalized together with extended unified methods. Graphical representation of the results are carried. They describe infinite soliton shapes, which arise from the multiple variation of the arbitrary functions in the solutions. It is, also, shown that internal magnetic field decays, asymptotically, to zero with time.

Basic MR physics

2018 ◽  
pp. 6-10
Author(s):  
Sebastian Kozerke ◽  
Redha Boubertakh ◽  
Marc Miquel
Keyword(s):  
Magnetic Field ◽  
Chemical Shift ◽  
Magnetic Moments ◽  
Image Contrast ◽  
Specific Time ◽  
Time Constants ◽  
Contrast Mechanisms ◽  
Transverse And Longitudinal Components ◽  
Mr Physics ◽  
Additional Image

In magnetic resonance, the properties of protons in tissue giving rise to so-called magnetic moments are exploited. The sum of many magnetic moments yields what is referred to as net magnetization, which can be seen as similar to the magnetization a bar magnet produces. The relation and interaction between magnetic moments, net magnetization, the static magnetic field, and radiofrequency fields are discussed. It is shown that radiofrequency excitation can be used to manipulate the net magnetization, such that it can be detected using radiofrequency antennae or coils. Upon excitation, the net magnetization will recover back to its equilibrium orientation with tissue-specific time constants for the transverse and longitudinal components, which, in turn, are important sources of image contrast in cardiac imaging. The discussion concludes with a foray into susceptibility and chemical shift effects resulting from different molecular environments in which protons can reside and which provide additional image contrast mechanisms.

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