Impact of Stress Annealing on the Magnetization Process of Amorphous and Nanocrystalline Co-Based Microwires.

Ahmed Talaat,Julián Gonzalez,Arcady Zhukov,Valentina Zhukova,Juan María Blanco,Mihail Ipatov

doi:10.3390/ma12162644

Ahmed Talaat, Julián Gonzalez + Show 4 more

Open Access

https://doi.org/10.3390/ma12162644

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Abstract

The domain wall (DW) dynamics of amorphous and nanocrystalline Co-based glass-coated microwires are explored under the influence of stress annealing. Different annealing profiles have enabled remarkable changes in coercivity and magnetostriction values of Co-based amorphous microwires with initially negative magnitude, allowing induced magnetic bistability in stress-annealed samples and, consequently, high DW velocity has been observed. Similarly, Co-based nanocrystalline microwires with positive magnetostriction and spontaneous bistability have featured high DW velocity. Different values of tensile stresses applied during annealing have resulted in a redistribution of magnetoelastic anisotropy showing a decreasing trend in both DW velocities and coercivity of nanocrystalline samples. Observed results are discussed in terms of the stress dependence on magnetostriction and microstructural relaxation.

Highlights

Domain wall (DW) propagation has become a topic in the spate of a number of emerging applications including a wide range of magnetic logics and nano-sized data storage devices [1,2,3,4]
The dynamic behavior of magnetic DWs determines the operational speed of such devices, and thereby knowledge of such dynamics and their dependence on external stimuli is crucial on both device and materials levels [3,4,5]
We report upon the influence of stress annealing on the magnetic properties and DW dynamics of Co-based amorphous and nanocrystalline glass-coated microwires with induced and spontaneous magnetic bistability, respectively

Summary

Introduction

Domain wall (DW) propagation has become a topic in the spate of a number of emerging applications including a wide range of magnetic logics and nano-sized data storage devices [1,2,3,4]. Around vanishing but still negative magnetostriction, fast DW velocities have been reported in amorphous Co-based microwires by means of controlling the annealing treatment conditions (i.e., changing the annealing temperature, time, and applied stresses) [18,25]. In these previous studies, the features of induced magnetic bistability have been discussed in consideration of the effect of annealing on the magnetostriction values and formation of axial domain structures in the inner cores of microwires. We evaluate the effect of different stress values on the magnetic properties and DW dynamics

Materials and Methods

Results and Discussion

80 MPa varying the annealing time timefrom from55toto30

Hysteresis loop ofof as-prepared

38.5 B18 Mo4 Cu1 of stress-annealed

Conclusions stress-annealing conditions conditions to study the magnetization