Antiferromagnet-Induced Perpendicular Magnetic Anisotropy in Ferromagnetic/Antiferromagnetic Bilayers and Trilayers
Bo-Yao Wang (王柏堯)1*
1Department of Physics, National Changhua University of Education, Changhua, Taiwan
* presenting author:Bo-Yao Wang, email:bywang1735@gmail.com
Antiferromagnet is a class of magnetic material with rich physics and potential application, but, however, had been underestimated for a long time in history because of lack of macroscopic magnetization and insensitivity to the external magnetic field. In the first part of this talk, I will report a new feature of an antiferromagnet, which can drive the magnetization of adjacent ferromagnetic (FM) films perpendicular [1]. The established perpendicular magnetization is attributed to the unpinned moments of the antiferromagnetic (AFM) film at interface with its thermal stability supported by a magnetic coupling with the underlying "compensated" pinned moments [2]. And then I will present that the antiferromagnet-induced PMA is not only sensitive to interfacial moments of AFM thin films, but also the magnetic interaction of such moments with volume moments, determined according to the vertical interlayer distance of the AFM thin film [3,4]. Finally, I will present the effect of antiferromagnet-induced PMA on FM/AFM/FM trilayers, and reveal its interplay with a long-range interlayer coupling between separated FM layers [5]. Our findings show an aspect other than the well-investigated phenomena on antiferromagnet and renew our knowledge on the roles of the magnetic moments of the antiferromagnet in nanomagnetism. This will also open an avenue for fundamental understanding of antiferromgnetism and provide a firm basis for the future design of the perpendicular-based magnetic or spintronic nanodevices.

References

[1] B.-Y. Wang, N.-Y. Jih, W.-C. Lin, C.-H. Chuang, P.-J. Hsu, C.-W. Peng, Y.-C. Yeh, Y.-L. Chan, W.-C. Chiang, D.-H. Wei, and M.-T. Lin*, ”Driving magnetization perpendicular by antiferromagnetic-ferromagnetic exchange coupling” Phys. Rev. B 83, 104417 (2011).
[2] B.-Y. Wang, J.-Y. Hong, K.-H. Ou Yang, Y.-L. Chan, D.-H. Wei, H.-J. Lin, and M.-T. Lin*, ”How antiferromagnetism drives the magnetization of a ferromagnetic thin film to align out-of-plane” Phys. Rev. Lett. 110, 117203 (2013).
[3] B.-Y. Wang*, J.-Y. Hong, N.-Y. Jih, K.-H. Ou Yang, L.-R. Chen, H.-J. Lin, Y.-L. Chan, D.-H. Wei, and M.-T. Lin*, “Probing magnetoelastic effects of ultrathin antiferromagnets via magnetic domain imaging in ferromagnetic -antiferromagnetic bilayers” Phys. Rev. B 90, 224424 (2014).
[4] B.-Y. Wang*, P.-H. Lin, M.-S. Tsai, C.-W. Shih, M.-J. Lee, C.-W. Huang, N.-Y. Jih, P.-Y. Cheng, and D.-H. Wei, “Crucial role of interlayer distance for antiferromagnet-induced perpendicular magnetic anisotropy” Phys. Rev. B 92, 214435 (2015).
[5] B.-Y. Wang*, P.-H. Lin, M.-S. Tsai, C.-W. Shih, M.-J. Lee, C.-W. Huang, N.-Y. Jih, and D.-H. Wei ”Antiferromagnet-induced perpendicular magnetic anisotropy in ferromagnetic /antiferromagnetic/ferromagnetic trilayers” Phys. Rev. B 94, 064402 (2016).



Keywords: Perpendicular magnetic anisotropy, Antiferromagnetic thin film