4 research outputs found
High frequency magnetic behavior through the magnetoimpedance effect in CoFeB/(Ta, Ag, Cu) multilayered ferromagnetic thin films
We studied the dynamics of magnetization through an investigation of the
magnetoimpedance effect in CoFeB/(Ta, Ag, Cu) multilayered thin films grown by
magnetron sputtering. Impedance measurements were analyzed in terms of the
mechanisms responsible for their variations at different frequency intervals
and the magnetic and structural properties of the multilayers. Analysis of the
mechanisms responsible for magnetoimpedance according to frequency and external
magnetic field showed that for the CoFeB/Cu multilayer, ferromagnetic resonance
(FMR) contributes significantly to the magnetoimpedance effect at frequencies
close to 470 MHz. This frequency is low when compared to the results obtained
for CoFeB/Ta and CoFeB/Ag multilayers and is a result of the anisotropy
distribution and non-formation of regular bilayers in this sample. The MImax
values occurred at different frequencies according to the used non-magnetic
metal. Variations between 25% and 30% were seen for a localized frequency band,
as in the case of CoFeB/Ta and CoFeB/Ag, as well as for a wide frequency range,
in the case of CoFeB/Cu.Comment: 14 pages, 5 figure