34 research outputs found
High sensitivity microwave detection using a magnetic tunnel junction in the absence of an external applied magnetic field
In the absence of any external applied magnetic field, we have found that a
magnetic tunnel junction (MTJ) can produce a significant output direct voltage
under microwave radiation at frequencies, which are far from the ferromagnetic
resonance condition, and this voltage signal can be increase by at least an
order of magnitude by applying a direct current bias. The enhancement of the
microwave detection can be explained by the nonlinear resistance/conductance of
the MTJs. Our estimation suggests that optimized MTJs should achieve
sensitivities for non-resonant broadband microwave detection of about 5,000
mV/mW
The tunneling magnetoresistance current dependence on cross sectional area, angle and temperature
The magnetoresistance of a MgO-based magnetic tunnel junction (MTJ) was studied
experimentally. The magnetoresistance as a function of current was measured
systematically on MTJs for various MgO cross sectional areas and at various
temperatures from 7.5 to 290.1 K. The resistance current dependence of the MTJ
was also measured for different angles between the two ferromagnetic layers. By
considering particle and angular momentum conservation of transport electrons, the
current dependence of magnetoresistance can be explained by the changing of spin
polarization in the free magnetic layer of the MTJ. The changing of spin polarization
is related to the magnetoresistance, its angular dependence and the threshold current
where TMR ratio equals zero. A phenomenological model is used which avoid
the complicated barrier details and also describes the data
Le spectromètre à ondes stationnaires et à Transformée de Fourier : Un outil de dosimétrie RF large bande et temps réel à bas coût
National audienc
"An RF spectrometer for fast wide band measurement"
International audienc
SWIFTS : l’interférométrie micro-ondes au service de la mesure spectrale instantanée et large bande
National audienc
A Broadband Standing Wave RF Interferometer for Fast and Low-Cost Spectral Analysis
International audienceS. Hemour, F. Podevin, et P. Xavie