Magnetic Coupling in Crystalline Compounds. A Phenomenological Theory of Magnetism in3dMetals

1960 ◽  
Vol 117 (2) ◽  
pp. 387-401 ◽  
Author(s):  
E. O. Wollan
Keyword(s):  
Magnetic Coupling ◽  
Phenomenological Theory

Grain separation enhanced magnetic coercivity in Pt/Co multilayers.

1993 ◽  
Vol 51 ◽  
pp. 1038-1039 ◽  
Author(s):  
G.A. Bertero ◽  
R. Sinclair
Keyword(s):  
Remanent Magnetization ◽  
Strong Influence ◽  
Uniaxial Anisotropy ◽  
Magnetic Coupling ◽  
Recording Media ◽  
Magnetic Media ◽  
Signal To Noise ◽  
Out Of Plane ◽  
Longitudinal Recording ◽  
The Relationship

Pt/Co multilayers displaying perpendicular (out-of-plane) magnetic anisotropy and 100% perpendicular remanent magnetization are strong candidates as magnetic media for the next generation of magneto-optic recording devices. The magnetic coercivity, Hc, and uniaxial anisotropy energy, Ku, are two important materials parameters, among others, in the quest to achieving higher recording densities with acceptable signal to noise ratios (SNR). The relationship between Ku and Hc in these films is not a simple one since features such as grain boundaries, for example, can have a strong influence on Hc but affect Ku only in a secondary manner. In this regard grain boundary separation provides a way to minimize the grain-to-grain magnetic coupling which is known to result in larger coercivities and improved SNR as has been discussed extensively in the literature for conventional longitudinal recording media.We present here results from the deposition of two Pt/Co/Tb multilayers (A and B) which show significant differences in their coercive fields.

Imaging magnetic microstructure with SEMPA

1993 ◽  
Vol 51 ◽  
pp. 1032-1033
Author(s):  
M. H. Kelley ◽  
J. Unguris ◽  
R. J. Celotta ◽  
D. T. Pierce
Keyword(s):  
Electron Microscopy ◽  
Thin Films ◽  
Scanning Electron Microscopy ◽  
Sandwich Structure ◽  
Magnetic Coupling ◽  
Polarization Analysis ◽  
Secondary Electrons ◽  
Magnetic Microstructure ◽  
Escape Depth ◽  
Scanning Electron

By measuring the spin polarization of secondary electrons generated in a scanning electron microscope, scanning electron microscopy with polarization analysis (SEMPA) can directly image the magnitude and direction of a material’s magnetization. Because the escape depth of the secondaries is only on the order of 1 nm, SEMPA is especially well-suited for investigating the magnetization of ultra-thin films and surfaces. We have exploited this feature of SEMPA to study the magnetic microstrcture and magnetic coupling in ferromagnetic multilayers where the layers may only be a few atomic layers thick. For example, we have measured the magnetic coupling in Fe/Cr/Fe(100) and Fe/Ag/Fe(100) trilayers and have found that the coupling oscillates between ferromagnetic and antiferromagnetic as a function of the Cr or Ag spacer thickness.The SEMPA apparatus has been described in detail elsewhere. The sample consisted of a magnetic sandwich structure with a wedge-shaped interlayer as shown in Fig. 1.

Magnetic Coupling of Ni, Cu and Co Bi- and Trilayers Probed by Magnetic Circular X-Ray Dichroism

1997 ◽  
Vol 7 (C2) ◽  
pp. C2-389-C2-395 ◽  
Author(s):  
F. May ◽  
M. Tischer ◽  
D. Arvanitis ◽  
J. Hunter Dunn ◽  
H. Henneken ◽  
...  
Keyword(s):  
Magnetic Coupling ◽  
X Ray

Optical Properties and Phenomenological Theory of Ferri-Ferri Phase Transitions in Antiferroelectric Liquid Crystals

1997 ◽  
Vol 7 (12) ◽  
pp. 1817-1828 ◽  
Author(s):  
P. Gisse ◽  
M. Sidir ◽  
V. L. Lorman ◽  
R. Farhi ◽  
J. Pavel ◽  
...  
Keyword(s):  
Optical Properties ◽  
Phase Transitions ◽  
Liquid Crystals ◽  
Phenomenological Theory ◽  
Antiferroelectric Liquid Crystals

Scaling Law of Coupling Coefficient and Coil Size in Wireless Power Transfer Design via Magnetic Coupling

2017 ◽  
Vol 137 (4) ◽  
pp. 326-333
Author(s):  
Chiaki Nagai ◽  
Kenji Inukai ◽  
Masato Kobayashi ◽  
Tatsuya Tanaka ◽  
Kensho Abumi ◽  
...  
Keyword(s):  
Coupling Coefficient ◽  
Scaling Law ◽  
Magnetic Coupling ◽  
Wireless Power Transfer ◽  
Power Transfer ◽  
Wireless Power ◽  
Coil Size

The Thanatosis of Enlightenment

2019 ◽  
Vol 29 (4) ◽  
pp. 83-106
Keyword(s):  
Scientific Reasoning ◽  
Phenomenological Theory ◽  
Human Mind ◽  
Unsuccessful Attempt ◽  
Trace Back ◽  
Methodological Errors ◽  
Psychological Models ◽  
History Of ◽  
Living Nature ◽  
Dialectic Of Enlightenment

The article analyzes methodological errors Theodore Adorno and Max Horkheimer’s Dialectic of Enlightenment, particularly their incorrect use of the concepts of mimicry and mimesis. The author of the article maintains that the leaders of the Frankfurt School made a mistake that threatens to undermine their argument when they juxtaposed mimesis and the attraction to death, which has led philosophers to trace back to mimesis the desire for destruction that is found in a civilization constructed by instrumental reasoning. The author reviews the arguments of the Dialectic of Enlightenment and emphasizes the unsuccessful attempt to fuse Freudian and Hegelian methods, which exposes the instability of opposing scientific reasoning to “living” nature. Some amusing quotations from Roger Caillois, who refused to think of mimesis as something entirely rational, are also brought to bear. As Brassier gradually unfolds Adorno and Horkheimer’s thesis, he indicates the consequences of their mistake, which confined thinkers to the bucolic dungeon of “remembering” the authentic nature that they cannot abandon because they have denied themselves access to both reductionist psychological models and to phenomenological theory as such. Brassier delineates the boundaries of this trap and notes the excessive attachment of the Dialectic of Enlightenment to the human. Brassier goes on to describe the prospects for a civilization of enlightenment: a mimesis of death in both senses (death imitates and is imitated) finds its highest expression in the technological automation of the intellect, which for Adorno and Horkheimer means the final implementation of the self-destructive mind. However, for Brassier it means the rewriting of the history of reason in space. This topological rewriting of history, carried out through an enlightenment, reestablishes the dynamics of horror more than mythical temporality: it will become clear that the human mind appears as the dream of a mimetic insect.

scholarly journals Superconducting Order Parameter Nucleation and Critical Currents in the Presence of Weak Stray Fields in Superconductor/Insulator/Ferromagnet Hybrids

Coatings ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 507
Author(s):  
Vasiliy N. Kushnir ◽  
Serghej L. Prischepa ◽  
Michela Trezza ◽  
Carla Cirillo ◽  
Carmine Attanasio
Keyword(s):  
Phenomenological Theory ◽  
Critical Currents ◽  
Superconducting Phase ◽  
Stray Field ◽  
Superconducting Properties ◽  
Ginzburg Landau ◽  
Ferromagnetic Layers ◽  
Linearized System ◽  
Critical Current Density Jc ◽  
Usadel Equations

The stray fields produced by ferromagnetic layers in Superconductor/Insulator/Ferromagnet (S/I/F) heterostructures may strongly influence their superconducting properties. Suitable magnetic configurations can be exploited to manipulate the main parameters of the hybrids. Here, the nucleation of the superconducting phase in an external magnetic field that periodically oscillates along the film width is studied on the base of the numerical solution of the linearized system of Usadel equations. In addition, the effect of the magnetic configuration of the F-layer on the temperature dependence of the critical current density, Jc(T), is investigated in the framework of the Ginzburg–Landau phenomenological theory on the base of the oscillating model of a stray field. By following this approach, the Jc(T) dependence of a Nb/SiO2/PdNi trilayer is reproduced for different magnetic configurations of the PdNi layer.

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