Very large magnetoimpedance effect in FeCoNi ferromagnetic tubes with high order magnetic anisotropy

Abstract

Articles you may be interested inGiant magneto-impedance effect in amorphous ferromagnetic wire with a weak helical anisotropy: Theory and experimentThe extraordinarily high ͑up to 800% magnetoimpedance ratio͒ and sensitive magnetoimpedance effect has been found and studied in FeCoNi magnetic tubes electroplated onto CuBe nonmagnetic wire at frequency of about 1 MHz order. Special annealing was done in order to induce magnetic anisotropy. The high harmonic response has been studied, and the harmonics show larger variations with the external magnetic field than the fundamental. This huge sensitivity of the harmonics ͑up to an order of the tens of thousands %/Oe͒ is promising in regard to the increase of the sensitivity of giant magnetoimpedance sensors. To explain the experiment results, we calculated the high frequency transverse susceptibility taking into account the magnetic anisotropy of first and second orders. The susceptibility is extremely high at the points of orientational phase transitions in the magnetic layer which gives rise to strong nonlinear effects.

Magnetic Properties and Magnetoimpedance of Electroplated Wires

“…It has been established that the high harmonics can show larger variation under application of an external magnetic field than the fundamental one. In order to explain the high sensitivity of the harmonics various theoretical models were proposed [2][3][4]. It was shown that for FeCoNi electroplated wires the strong nonlinear effects are the consequence of the high value of the transverse susceptibility at the points of re-orientational phase transitions in the magnetic layer and that the high-order magnetic anisotropy may play a key role [3][4].…”

“…In 1996 Beach at el [2] has re-discovered these materials for technological applications (low magnetic field sensors) and basic studies of non-linear processes. Non-linearity of the magnetization processes was proved for different compositions of the electroplated [3][4] and composite [5] wires by Fourier analysis of the induced voltage (the high harmonics generation) and nonlinear dependence of the induced voltage on the driving current amplitude. It has been established that the high harmonics can show larger variation under application of an external magnetic field than the fundamental one.…”

“…In order to explain the high sensitivity of the harmonics various theoretical models were proposed [2][3][4]. It was shown that for FeCoNi electroplated wires the strong nonlinear effects are the consequence of the high value of the transverse susceptibility at the points of re-orientational phase transitions in the magnetic layer and that the high-order magnetic anisotropy may play a key role [3][4]. Special attempts were made in order to design new family of the electroplated wires adapted for giant magnetoimpedance (GMI) applications [4,6].…”

Thin-Film Magneto-Impedance Sensors

“…The advantages of this layered structure were also incorporated in wire-shaped specimens to achieve MI ratios of 800%, the largest reported in the literature [17]. Analytical expressions similar to Eq.…”

Magnetoimpedance effect of the Ni80Fe20/Cu composite wires: The influence of DC current imposed on the Cu base

“…15 When the frequency continues to increase, the loss caused by the eddy damp enhances. 16,17 The magnetization caused by the magnetic domain motion gradually weakens until it completely disappears. It only has the magnetization caused by the rotation of the magnetic moment, so the magnetic permeability decreases, and the maximum impedance ratio reduces with frequency increasing.…”