Large magnetoresistance in magnetoimpedance of Co68Fe5Nb12B15 ribbons

Effect of annealing on magnetoimpedance of Co68Fe4Zr10Cu2B16 ribbons

“…Further increase in the static magnetic field could inhibit the wall movement and impel the rotation of the domains as the effective transverse permeability m j decreases sharply leading to a strong MI effect. The double peak behavior (the field value at the peak is the anisotropy field H k ) confirms the damping of domain wall motions and shows that tangential magnetization proceeds by the rotation of the domains [10,12].…”

“…The decrease in the maximum MI with increase in frequency is due to the significant decrease of effective permeability, which is originated from the strong suppression of domain wall movement by the eddy current effect. At high frequencies, Z ¼ ½ð1 À iÞrL=2t1=d where L and t are the length and width of the ribbons, respectively, d is the skin depth and is given by ffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffi ffi ð2=m j soÞ q and s is the conductivity of the sample [4,10]. Thus, at high frequencies, there is a decrease in the permeability causing an improvement in the current density which is equivalent to a decrease in impedance, and hence, the MI response.…”

“…MI has been extensively studied in Fe-and Co-rich amorphous ribbons and wires [6][7][8][9][10]. The magnetic domain structure of low magnetostrictive amorphous materials can be modified to optimize the MI response by inducing transverse magnetic anisotropy using suitable annealing conditions.…”

Magnetoimpedance, magnetoinductance and AC magnetoresistance studies on amorphous and nanocrystalline ribbons

“…At low frequencies, the resistance of the sample is equal to the dc resistance but at a high frequency it deviates due to the eddy current and the hysteresis losses. Thus above 10 MHz, variation of the resistance with the field gives rise to the AC magnetoresistance (ACMR) [4]. At low frequencies, the contribution from the changes in transverse permeability resulting from domain wall motion to MI is dominant over magnetization rotation.…”