Anomalous Hall-like effect probe of antiferromagnetic domain wall

Lili Lang,Shiming Zhou,Xuepeng Qiu

doi:10.1038/s41598-017-18514-4

Lili Lang, Shiming Zhou + Show 1 more

Open Access

https://doi.org/10.1038/s41598-017-18514-4

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Abstract

Of crucial importance to antiferromagnetic (AF) spintronic devices, AF domain wall (AFDW), created in exchange biased Y3Fe5O12/Ni0.50Co0.50O (NiCoO)/Pt, is characterized by anomalous Hall-like effect through magnetic proximity effect and spin Hall magnetoresistance at NiCoO/Pt interface. The AFDW thickness, in the order of nanometers, has been for the first time proved in experiments to increase with increasing temperature. AF spins within AFDW show the same chirality in decent and ascent branches of ferromagnetic magnetization reversal process. Moreover, the uncompensated magnetic moment at the NiCoO/Pt interface is of perpendicular magnetization anisotropy and changes linearly in magnitude with temperature due to the reduced coordination of the magnetic atoms on the AF surface. This work will help to clarify the mechanism of the spin current propagation in AF materials and fully understand the physics behind exchange bias.

Highlights

Antiferromagnetic (AF) materials are becoming increasingly important in the newly merging AF spintronics field[1,2,3]
The pioneered theoretical works have proposed the new generation spintronic devices based on AF domain wall, i.e., AFDW14–16
The magnetic proximity effect (MPE) helps to analyze the motion of the uncompensated magnetic moment (UMM) at NiCoO/Pt interface during the FM magnetization reversal process

Summary

Results and Discussion

The MPE helps to analyze the motion of the UMM at NiCoO/Pt interface during the FM magnetization reversal process. Since the UMM has perpendicular magnetic anisotropy and negligible in-plane anisotropy due to its polycrystalline structure (Fig. S6)[24] whereas the epitaxial YIG layer, as an in-plane film, has an in-plane magnetic anisotropy, both polar and azimuthal angles of AF and FM spins change with the atomic plane index during the FM magnetization reversal process. The AHLE loop for d = 1.25 nm is asymmetric near 40 K and symmetric at higher temperatures, as shown in the right column of Fig. 3 This phenomenon reproduces one of the fingerprints for the exchange bias, i.e., asymmetric/symmetric FM magnetization reversal process at low and high temperatures[4]. For d > ξAF, less magnons reach at the upper interface and the efficiency of spin pumping and thermal spin current injection is reduced

Conclusion

Author Contributions

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