scholarly journals Impact of Schumann resonances on the Einstein Telescope and projections for the magnetic coupling function

2021 ◽  
Vol 104 (12) ◽  
Author(s):  
Kamiel Janssens ◽  
Katarina Martinovic ◽  
Nelson Christensen ◽  
Patrick M. Meyers ◽  
Mairi Sakellariadou
Author(s):  
G.A. Bertero ◽  
R. Sinclair

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.


Author(s):  
M. H. Kelley ◽  
J. Unguris ◽  
R. J. Celotta ◽  
D. T. Pierce

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.


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

2017 ◽  
Vol 137 (4) ◽  
pp. 326-333
Author(s):  
Chiaki Nagai ◽  
Kenji Inukai ◽  
Masato Kobayashi ◽  
Tatsuya Tanaka ◽  
Kensho Abumi ◽  
...  

Author(s):  
Zhi-Juan Liao ◽  
Qi-Kai Feng ◽  
Chen-Hui Jiang ◽  
Fan Wu ◽  
Chen-Yang Xia ◽  
...  

Energies ◽  
2021 ◽  
Vol 14 (6) ◽  
pp. 1568
Author(s):  
Bernhard Wunsch ◽  
Stanislav Skibin ◽  
Ville Forsström ◽  
Ivica Stevanovic

EMC simulations are an indispensable tool to analyze EMC noise propagation in power converters and to assess the best filtering options. In this paper, we first show how to set up EMC simulations of power converters and then we demonstrate their use on the example of an industrial AC motor drive. Broadband models of key power converter components are reviewed and combined into a circuit model of the complete power converter setup enabling detailed EMC analysis. The approach is demonstrated by analyzing the conducted noise emissions of a 75 kW power converter driving a 45 kW motor. Based on the simulations, the critical impedances, the dominant noise propagation, and the most efficient filter component and location within the system are identified. For the analyzed system, maxima of EMC noise are caused by resonances of the long motor cable and can be accurately predicted as functions of type, length, and layout of the motor cable. The common-mode noise at the LISN is shown to have a dominant contribution caused by magnetic coupling between the noisy motor side and the AC input side of the drive. All the predictions are validated by measurements and highlight the benefit of simulation-based EMC analysis and filter design.


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