Microwave magnetoabsorption in glass-coated amorphous microwires with radii close to skin depth

Abstract

Lofland, S.; García Miquel, ÁH.; Vázquez, M.; Bhagat, S. (2002). Microwave magnetoabsorption in glass-coated amorphous microwires with radii close to skin depth. Journal of Applied Physics. 92(4): 2058-2063. doi:10.1063/1.1494847 Microwave magnetoabsorption in glass-coated amorphous microwires with radii close to skin depth ͑͒We present the frequency dependence of microwave magnetoabsorption in glass-coated amorphous microwires of (Co 100Ϫx Fe x ) 72.5 Si 12.5 B 15 . The data were taken at room temperature in the frequency range of 1-60 GHz for field up to 15 kOe by either a cavity perturbation technique or a coaxial transmission line. The resulting spectra strongly depend upon the local microwave magnetic and electric fields We have found that we can simulate the spectra using an analytic solution to the problem of electromagnetic scattering from a cylinder. We demonstrate that these unusual spectra can be interpreted in terms of ferromagnetic resonance and antiferromagnetic resonance. However, because the electromagnetic skin depth is comparable to the radius, the resonance and antiresonance field do not follow the conventional equations.

DC and AC linear magnetic field sensor based on glass coated amorphous microwires with Giant Magnetoimpedance

“…We also apply a bias field in order to work on the field over the GMI peak, where the hysteresis is negligible. GMI in amorphous microwires has been also studied at microwave frequencies [15,25], and also the absorptive properties due to the phenomenon of Ferromagnetic Resonance (FMR) [26][27][28][29], or the recently experimental demonstration of its behavior as a metamaterial due to the coexistence of negative permittivity and permeability in the frequency region between FMR and Ferromagnetic Antiresonance (FMAR) [30]. This structure allows the possibility of modifying a pass band between FMR and FMAR through an external magnetic field [30] or with a current though the microwire [31], even modulating a microwave signal with an AC current.…”

Mössbauer spectroscopy studies of spin reorientations in amorphous and crystalline (Co0.2Fe0.8)72.5Si12.5B15 glass coated micro-wires

“…The analysis and the characterization of the wires were described in Ref. [4]. 57 Fe Mo¨ssbauer studies of magnetic micro-wires of (Co 0.2 Fe 0.8 ) 72.5 Si 12.5 B 15 were performed using a conventional constant acceleration drive in the transmission mode, in conjunction with a 30 mCi 57 Co:Rh source.…”

“…These materials were proposed in applications as sensing elements in sensor devices, as active elements in magnetic shielding or making use of their absorption characteristics [4]. Therefore, particular interest was focused on their properties such as magneto-impedance and microwave behavior.…”

Glass-coated amorphous ferromagnetic microwires at microwave frequencies

“…In this case, the microwires are inserted parallel to the axis of the coaxial line instead of the dielectric filler. The line is shorted, hence the scattering S 11 parameter (relating the incident to reflected power measured with a network analyser) [9,41] is directly linked to the absorption power.…”

“…In the microwave frequency range, microwires exhibit very interesting properties: the ferromagnetic resonance (FMR) itself presents quite interesting particularities, such as the so-called natural FMR (NFMR) [4,5] and microwave power absorption [6][7][8][9], and the permeability provides interesting responses for various geometrical configurations of the electrical and magnetic fields.…”