Stress dependence of the giant magneto-impedance effect in amorphous wires

Abstract

The recently discovered giant magnetc-impedance (GMI) effect has been measured as a function of circular +ving-field frequency and applied tensile stress on two nearrem-magnetostriction amorphous wires. The effect of different orientations of the induced magneroelastic anisompy has been verified. for the fim time, by using wires with opposite magnetosttiction constant, .Ls, signs ~~,vCo,,.tNh,,sSi,.sBls. i s = 1.5 x IO"; and Co68.IFe4.~Si1*,sBIS1 i s = -4 x IO-'). cMI ratios up to 300% were found in the magnetically softer (lower-magnetostriction) wire. The frequency dependence of GMI bas been found to be strongly influenced by the magnetoelastic anisotropy induced in the amorphous wires. Results are interpreted in terms of changes in the magnetic penatation depth by modifiCations in the circumferential permeability originated by the action of extemal agents as field and mechanical stresses. GMI is therefore found to be largely determined by the magnetic domain configuration and relative contributions of both domain wall motions and magnetic moment rotations to the overall magnetization process.

Penetration depth and magnetic permeability calculations on GMI effect and comparison with measurements on CoFeB alloys

“…MI has been extensively investigated in melt-spun amorphous ribbons [10], conventional amorphous wires (prepared by in-rotating water quenching technique) [11], thin films [12] and glass covered microwires (prepared by TaylorUlitowsky method) [4,5,[7][8][9], establishing the efficiency of MI elements in low magnetostrictive materials. Magnetic properties of MI elements can be tailored to get optimal response by choosing proper composition, particular experimental conditions and annealing treatments.…”

Investigation on the Giant Magnetoimpedance of Fe<SUB>89&minus;<I>x</I></SUB>Zr<SUB>7</SUB>B<SUB>4</SUB>Al<I><SUB>x</SUB></I> (<I>x</I>=0 and 2.5) Nanocrystalline Ribbons

“…Earlier works on GMI effect were on CoFeSiB amorphous wires. [1][2][3][4] Now it has been extended to Co-Fe-Si-B amorphous ribbons, [5][6][7] Fe-Zr-B, 8,9) Fe-Zr-B-Cu, 10,11) Fe-Zr-B-Cu-Al, 12) Fe-Nb-B, 13) Fe-Hf-B, 14) Fe-P-C-Mo-Cu-Si, 15) Fe-Cu-Nb-Si-B, [16][17][18] Fe-Cu-NbSi-B-Al 19) nanocrystalline ribbons, Ni-Fe-Mo permalloy wires/flakes, 20,21) pure Fe wires, 22,23) Ni-Fe/Cu/Ni-Fe, 24) Co-Si-B/(Cu,Ag)/Co-Si-B 25) sandwich films, Be-Cu/NiFe, 26) Ag/Ni-Fe, 27) Cu/Co-P 28) plated wires, manganites La-A-Mn-O (A ¼ Sr, Ba, Ca) 29,30) and Mn-Zn ferrites. 31) The GMI effect consisting a sensitive change of impedance under a dc magnetic field is of important applications in various magnetic sensors.…”

Effect of annealing on magnetoimpedance of Co68Fe4Zr10Cu2B16 ribbons

“…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.…”