Jeroen Schoenmaker

Dr. Jeroen Schoenmaker


Research Focus & Metrics

Academic Career Length

30Years (1997-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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13 October 1997 in Applied Physics Letters
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Journal Article
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MSM. L. Sartorelli
M. L. Sartorelli
MKM. Knobel
M. Knobel
JSJeroen Schoenmaker
Jeroen Schoenmaker
JGJ. Gutierrez
J. Gutierrez
JBJ. M. Barandiarán
J. M. Barandiarán
Systematic measurements of giant magneto-impedance (GMI) and its relaxation (magneto-impedance aftereffect) have been carried out in a series of Co-rich amorphous ribbons ranging in magnetostriction values from −3.5 to +3.5 ppm. The value of GMI is a maximum for the alloy with the lowest value of magnetostriction, corresponding to a maximum of the transverse permeability. The impedance relaxation between two fixed times depends on the magnetostriction constant (λs) of the samples, and the observed trend is consistent with the theories which predict a direct relationship of the conventional permeability aftereffect (MAE) with the square of λs. Furthermore, the variation of the impedance aftereffect with the driving current resembles the behavior of MAE, and a connection between both effects can be established.

12 July 2010 in Applied Physics Letters
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Journal Article
Closed access
FGF. Garcia
F. Garcia
HWH. Westfahl
H. Westfahl
JSJeroen Schoenmaker
Jeroen Schoenmaker
ECE. J. Carvalho
E. J. Carvalho
ASA. D. Santos
A. D. Santos
AGA. P. Guimarães
A. P. Guimarães
Tailoring the properties of magnetic vortices through the preparation of structured multilayers is discussed. The dependence of the vortex core radius r on the effective anisotropy is derived within a simple model, which agrees with our simulations. As the perpendicular anisotropy increases, r also increases until a perpendicular magnetization appears in the disk rim. Co/Pt multilayer disks were studied; x-ray microscopy confirms qualitatively the predicted behavior. This is a favorable system for implementing vortex-based spin-transfer nano-oscillator devices, with enhanced rf power resulting both from the increase in the core size and synchronization afforded by the coupling of the Co layers.

1 June 1997 in Materials Science and Engineering: A
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Journal Article
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MKM. Knobel
M. Knobel
JSJeroen Schoenmaker
Jeroen Schoenmaker
JSJoao Paulo Sinnecker
Joao Paulo Sinnecker
RTR. Sato Turtelli
R. Sato Turtelli
RGR. Grössinger
R. Grössinger
HSH. Sassik
H. Sassik

5 August 2014 in Entropy
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JSJeroen Schoenmaker
Jeroen Schoenmaker
We performed an in depth analysis of the subjects of entropy and the second law of thermodynamics and how they are treated in astrophysical systems. These subjects are retraced historically from the early works on thermodynamics to the modern statistical mechanical approach and analyzed in view of specific practices within the field of astrophysics. As often happens in discussions regarding cosmology, the implications of this analysis range from physics to philosophy of science. We argue that the difficult question regarding entropy and the second law in the scope of cosmology is a consequence of the dominating paradigm. We further demonstrate this point by assuming an alternative paradigm, not related to thermodynamics of horizons, and successfully describing entropic behavior of astrophysical systems.

1 March 2011 in Renewable Energy
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Journal Article
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JSJeroen Schoenmaker
Jeroen Schoenmaker
JRJ.F.Q. Rey
J.F.Q. Rey
KPK.R. Pirota
K.R. Pirota

1 August 2013 in Review of Scientific Instruments
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Journal Article
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JSJeroen Schoenmaker
Jeroen Schoenmaker
KPK. R. Pirota
K. R. Pirota
JTJulio Carlos Teixeira
Julio Carlos Teixeira
Tailoring magnetic flux distribution is highly desirable in a wide range of applications such as magnetic sensors and biomedicine. In this paper we study the manipulation of induced currents in passive devices in order to engineer the distribution of magnetic flux intensity in a given region. We propose two different approaches, one based on especially designed wire loops (Lenz law) and the other based on solid conductive pieces (eddy currents). The gain of such devices is mainly determined by geometry giving perspective of high amplification. We consistently modeled, simulated, and executed the proposed devices. Doubled magnetic flux intensity is demonstrated experimentally for a moderate aspect ratio.