Flexible Spin Valves: Interlayer Interaction and Deformation Sensitivity

L I Naumova,R S Zavornitsyn,I K Maksimova,M A Milyaev,A A Zakharov,V V Proglyado,T A Chernyshova,V V Ustinov

doi:10.1134/s0031918x21110090

L I Naumova, R S Zavornitsyn + Show 6 more

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https://doi.org/10.1134/s0031918x21110090

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Abstract

Exchange-coupled spin valves based on ferromagnetic alloys CoFeNi and antiferromagnetic alloy FeMn are obtained on flexible polyimide substrates by magnetron sputtering. The magnetoresistive properties of films and microstrips of spin valves are measured at various degrees of bending deformation of the sample. The behavior of the dependence of the deformation sensitivity of the spin valve on the interaction between the magnetic layers and on the arrangement of the anisotropy axes with respect to the deformation vector is characterized. It is found that the deformation sensitivity decreases with an increase in the interval between the fields of magnetization reversal of the free and fixed layers in the spin valve.

Highlights

Levity, small thickness, adaptability to the measured surface, and impact resistance are advantages of nanostructures on polymer substrates
We introduced a layer of an FM alloy with a nonzero magnetostriction (Co70Fe10Ni20) into the spin valve
It is shown that the use of five to seven recurrences of the [Ta(5 nm)/NiFeCr(5 nm)] composition in the buffer layer can effectively reduce the effect of the roughness of the polymer substrate on the magnetoresistance and the nature of the interlayer interaction in the spin valve

Summary

Introduction

Small thickness, adaptability to the measured surface, and impact resistance are advantages of nanostructures on polymer substrates. Magnetic materials exhibit magnetostriction; it is important to study the effect of the mechanical stimulus on the magnetic characteristics of films. In a nanostructure that is composed of two ferromagnetic (FM) layers separated by a nonmagnetic layer, the resistivity depends on the angle between the magnetic moments of the FM layers (giant magnetoresistance (GMR) effect). In addition to the sensitivity to the magnetic field, the direction of magnetization in the FM material is sensitive to the degree and direction of deformation due to the Villari effect (inverse magnetostrictive effect) [14]. The direction of the magnetic moment of the layer changes upon exposure to mechanical stresses, which leads to a change in the magnetoresistance

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