Influence of spacer layer in exchange coupled NiFe/Cu/IrMn trilayer structure

A set of partially uncoupled NiFe/Cu/IrMn exchange biased thin films with variable thickness of non-magnetic Cu spacer is characterized by ferromagnetic resonance (FMR) and Brillouin light scattering (BLS) techniques applied complementary to reveal time-scale dependent effects of uncoupling between ferromagnetic and antiferromagnetic layers on high-frequency magnetization dynamics. The results correlate with interfacial grain texture variations and static magnetization behavior. Two types of crystalline phases with correlated microwave response are revealed at the ferro–antiferromagnet interface in NiFe/Cu/IrMn thin films. The 1st phase forms well-textured NiFe/IrMn grains with NiFe (111)/IrMn (111) interface. The 2nd phase consists of amorphous NiFe/IrMn grains. Intercalation of NiFe/IrMn by Cu clusters results in relaxation of tensile strains at the NiFe/IrMn interface leading to larger size of grains in both the NiFe and IrMn layers. The contributions of well-textured and amorphous grains to the high-frequency magnetization reversal behavior are distinguished by FMR and BLS techniques. Generation of a spin-wave mode is revealed in the well-textured phase, whereas microwave response of the amorphous phase is found to originate from magnetization rotation dominated by a rotatable magnetic anisotropy term. Under fixed FMR frequency, the increase of Cu thickness results in higher magnetization rotation frequencies in the amorphous grains.

Section: High-frequency Magnetization Dynamics and Fmrsupporting

confidence: 57%

Section: Introductionmentioning

confidence: 99%

Modulation of interfacial magnetic relaxation timeframes by partially uncoupled exchange bias

Bakhmetiev¹,

Таланцев²,

Садовников³

et al. 2021

“…Thus, the H ex can be well-tuned in FM/NM/AF trilayer sensor structures by varying the thickness of the NM spacer layer. The exchange bias decreases exponentially with the increase of the spacer layer thickness and vanishes around 1 nm thickness while this thickness is enough to completely separate the FM/AF layers [65,93,[157][158][159][160][161]. In the literature, mostly the Cu material has been used as a spacer layer.…”

Section: Trilayersmentioning

confidence: 99%

Current trends in planar Hall effect sensors: evolution, optimization, and applications

Elzwawy

Pişkin

Akdoğan

et al. 2021

The advantages of planar Hall effect (PHE) sensors-their thermal stability, very low detection limits, and high sensitivities-have supported a wide range of advanced applications such as nano-Tesla (nT) magnetometers, current sensing, or low magnetic moment detection in lab-on-a-chip devices. In this review we outline the background and implications of these PHE sensors, starting from fundamental physics through their technological evolution over the past few decades. Key parameters affecting the performance of these sensors, including noise from different sources, thermal stability, and magnetoresistance magnitudes are discussed. The progression of sensor geometries and junctions from disk, cross-to-bridge, ring, and ellipse configuration is also reviewed. The logical sequence of these structures from single magnetoresistive layers to bi-, tri-layers, and spin-valves is also covered. Research contributions to the development of these sensors are highlighted with a focus on microfluidics and flexible sensorics. This review serves as a comprehensive resource for scientists who wish to use PHE for fundamental research or to develop new applications and devices. The conclusions from this report will benefit the development, production, and performance evaluation of PHE-based devices and microfluidics, as well as set the stage for future advances.

“…With increase of t Spacer from 0.3 nm to 0.7 nm the operating field range reduces almost 3 times, while the change of amplitude of PHE signal is less than 2 percent. The dependence of oper ating field range on Cu thickness (figure S2 in the supplemen tary material) has been approximated [33,43], as:…”

Section: Reduction Of Power Consumption By Thickness Variation Of Non...mentioning

confidence: 99%

Equisensitive adjustment of planar Hall effect sensor’s operating field range by material and thickness variation of active layers

Elzwawy

SungJoon

Таланцев

et al. 2019

A novel technique of operating field range adjustment using varying thicknesses of spacer and capping layers is proposed for planar Hall effect (PHE) magnetic sensors. In terms of this technique, the spacer and capping layer thicknesses are varied interdependently, in a way that the variation of the operating magnetic field range is performed without a change of sensitivity. The relationship between the thicknesses of spacer and capping layers required for this 'equisensitive' variation of field range are calculated and experimentally approved. The active layer material substitution effect on the performance of PHE sensor is studied. The sensitivity, output voltage, operating field range, and shunt current are compared for PHE sensors, based on NiFe and NiFeMo active ferromagnetic layers. The NiFe/IrMn and NiFeMo/ IrMn interface coupling energies are compared and the effect of IrMn crystallinity on their difference is discussed. The range of active layer thicknesses, at which the operating field range can be varied while maintaining the sensitivity at the same value, has been determined.