Large nonlinear magnetoimpedance in amorphous Co80.89Fe4.38Si8.69B1.52Nb4.52 fibers

Abstract

Fourier analysis of the nonlinear response of the impedance signal of amorphous Co80.89Fe4.38Si8.69B1.52Nb4.52 fibers is presented. The harmonic components of the voltage signal present a strong asymmetry. A strong variation (around 1400%) of the second-harmonic signal (V2 f) as a function of the applied magnetic field is observed. Nonlinear effects and the asymmetric behavior in harmonics can be associated with the anisotropies induced during the fabrication process. These results can lead to improvement of the performance of future magnetoimpedance sensors.

The effect of domain-walls motion on second harmonic amplitude of magnetoinductive response in Co-based amorphous wires

“…Nevertheless, it should be noted that the calculated dependences explain qualitatively some experimental results on the study of nonlinear effects in Co-based amorphous wires. In particular, the linear dependence of the second harmonic amplitude on the frequency has been observed for both the voltage at the wire ends [11] and the pick-up coil voltage [4]. The increase of the second harmonic in the voltage across the wire with the increase of the anisotropy axis deviation angle predicted by the model is in agreement with experimental data [6,10,14].…”

“…Recently, some new results concerning the frequency spectrum of the voltage at higher AC current amplitudes have been reported [4][5][6][7][8][9][10][11][12][13][14]. In this case, the relation between the sample magnetization and the current amplitude becomes nonlinear.…”

Torsional stress impedance effect in Fe 71 Cr 7 Si 9 B 13 amorphous wire

“…An increase of the magnetoimpedance response from 15% to 45% under the torsional stress with 0.235 rad/cm has been observed. This increase in the magnetoimpedance response of as-received wire can be related to the formation of intermediate circular domains between inner core and outer shell domains of wire [6][7][8]. On the other hand, the further increase of the torsional stress results in a decrease in the magnitude of magnetoimpedance effect.…”

“…Also, the current annealed wires do not show any increase with increasing torsional stress, the impedance of these wires directly starts to decrease with the applied torsion. A simple model similar to the previously reported based on magnetic moment rotation was developed [7]. It is well known that the transverse susceptibility, χ t , is proportional to the impedance of the sample, Z, through the expression t πχ 4 1 + ∝ Ζ [1,2].…”

Effects of helical anisotropy on nonlinear voltage response in amorphous wires

“…At higher current amplitudes, the voltage response becomes nonlinear and consists of a number of harmonics [5,6]. The appearance of higher harmonics in the voltage across a sample has been detected and analyzed recently for Co-based amorphous wires [7][8][9][10][11], CuBe/FeCoNi-electroplated wires [12,13], amorphous ribbons [14] and composite materials consisting of a copper wire sandwiched between Co-based amorphous ribbons [15].…”