Giant Magnetoimpedance of Cube/Feconi Electroplated Wires: Focus on Angular Sensoric

Abstract

Giant magnetoimpedance effect (GMI) is a subject of special interest proved by applied electrodynamic and technological applications. GMI effect in ferromagnetic tubes is connected with the high sensitivity of the magnetic system to a circular magnetic field near the spin-reorientation magnetic phase transitions offering high sensitivity with respect to an external magnetic field. In this work the non-magnetic CuBe wires were covered by Fe 20 Co 6 Ni 74 layers by electrodeposition. The thickness of 1 μm for magnetic layer was high enough in order to ensure the high GMI value. Longitudinal magnetic anisotropy was induced by post preparation annealing in a magnetic field of 160 A/m at 320˚C during 1 hour in order to obtain appropriate magnetisation process. Angular dependencies of GMI were measured in a frequency range of 1 to 10 MHz for driving currents of 2.5 to 20 mA. High longitudinal GMI of the order of 400% was observed at quite low frequency of 1 MHz. The highest value of the sensitivity of 520%/Oe was found for the active resistance: Linear sensitivities of 0.023 Ω/˚ and 0.05 Ω/˚ were observed for reasonably low fields of 240 and 275 A/m respectively for small angles, where planar GMI elements are less effective.

Effects of Current Pulsation on Magnetic Properties and Giant Magnetoimpedance of Electrodeposited NiFe Coatings on Cu Wires

“…To put the MI response investigated in this study in perspective, Fig. 6 shows maximum MI ratios from the up-field sweep and sensitivity of the specimens from the 0.4 MHz measurement in comparison to other MI alloy coatings reported in the prior related studies [18,[35][36][37][38]. Overall, the NiFe alloys investigated here show relatively high MI ratio with moderate sensitivity.…”

“…In contrast, the surface of specimens in the PC group appears to be rather uniform in a micro-scale, with refined nodules and absence of cracks. This is owed to an improvement of a uniformity of a double layer on a sample's surface during electrodeposition with current pulsation, resulting in a high micro-throwing power and hence a smoother deposition profile [11,18]. Among the PC group samples, PC1, which was plated with the low-frequency applied current, appears to have relatively more refined and uniform surface morphology.…”

“…6. Maximum MI ratios from the up-field sweep and sensitivity of the samples in DC and PC groups plotted against related materials reported in literatures [18,[35][36][37][38]…”

Ориентационная зависимость магнитного момента микропроводов alpha-Fe(PrDy)(CoFeB)

“…Хотя возможность модификации магнитной фазы, и соответственно остаточной намагниченности, коэрцитивной силы и тд, в микропроводах на основе NdFeB/Ta были показаны в [11]. Коаксиальная двухфазная структура микропровода приводит не только к появлению эффекта GMI, но и к конкуренции магнитной анизотропии ядра и оболочки, которая приводит к формированию спирального [12] или азимутального [13] направления намагниченности в микропроводе. Данные о магнитной анизотропии ядра и оболочки микропровода могут быть получены из анализа анизотропии магнитных свойств микропровода.…”