Tailoring the magnetoimpedance effect of NiFe/Ag multilayer

Abstract

The magnetoimpedance (MI) effect was investigated in NiFe/Ag multilayered (ML) and ML/SiO 2 /Ag/SiO 2 /ML structured multilayered (SD) ferromagnetic films grown by magnetron sputtering. The MI measurements were performed with an impedance analyzer over a wide frequency range, from 10 MHz to 1.8 GHz. Sample geometries are mainly responsible for the different MI behaviours and by considering the entire frequency range, distinct mechanisms responsible for MI changes were associated. For the ML sample, a maximum value of 80%, associated with the appearance of ferromagnetic resonance (FMR), was reached at around 1 GHz. For the SD sample, the striking feature is the existence of two distinct frequency ranges with high MI% values of 80% at around 100 MHz, related to the skin and magnetoinductive effects, and of 120% at around 1 GHz, associated with the strong skin and FMR effect.

Magnetization dynamics in nanostructures with weak/strong anisotropy

“…31. This contribution at moderate frequency ranges may be associated with the presence of random local anisotropies induced by stress.…”

“…Besides, it is noticeable that the anisotropy induction in the Py/Cu multilayered films is weaker than that observed for the Py/Ag ones, a behavior consistent with results previously reported for multilayered films with Cu and Ag employed as metallic spacer materials. 31,32 In particular, for the Py/Cu multilayered films, presented in Figs. 3(a)-3(c), due to the weak anisotropic magnetic behavior, the saturation field H s values are close for both cuts, being $1.0 Oe for EA and $2.5 Oe for HA, independently on the number of bilayers.…”

“…6,8 Since the discovery of the effect, MI has been studied in a wide variety of systems, e. g., sheets, 9 wires, [10][11][12][13][14][15][16][17][18] ribbons, [19][20][21][22][23][24] and thin films. [25][26][27][28][29][30][31][32][33][34][35][36][37][38][39] In the particular case of films, an increasing interest has been devoted to the effect in single layered, 25,26 multilayered, [27][28][29][30][31][32] and structured multilayered thin films, 30,31,[33][34][35][36][37][38][39] since ...…”

Magnetized Plasma as a Versatile Platform for Switching

“…Similar to the Hall effect based devices, there is another fascinating way to control the light propagation called giant magneto-resistance (GMR) or giant magneto-impedance (GMI) effect [11,12], in which magnetic materials suffering a significant change of electrical resistance (or impedance) when subjected to an external magnetic field. The impedance change in GMI effect can be described using Maxwell equation for specific boundary conditions and is controlled by the changes of the material's permeability [13]. A traditional approach to design nonreciprocal devices is based on magneto-optical effect [14,15] in which electromagnetic and optical waves through a medium may be manipulated and controlled by the presence of a quasi-static magnetic field.…”

Особенности Гигантского Магнитоимпедансного Эффекта В Пленочных Структурах На Основе Пермаллоя В Интервале Температур, Важных Для Практических Приложений

“…Однако хорошо известно, что получить магнитомяг-кие пленки пермаллоя такой толщины методом ионно-плазменного распыления не удается из-за их перехо-да в " закритическое" состояние [10,14]. Технологиче-ским решением данной проблемы стало дополнительное наноструктурирование ферромагнитных слоев [15][16][17]. Исследования температурной зависимости ГМИ таких структур отсутствуют в научной литературе.…”