|Title:||Field-free spin-orbit torque switching through domain wall motion||Authors:||Chang, Liang Juan
Liao, Wei Bang
Wang, Ting Chien
Tsai, Tsung Yu
Tsai, Li Zai
Lee, Shang Fan
|Issue Date:||30-Sep-2019||Journal Volume:||100||Journal Issue:||10||Source:||Physical Review B||Abstract:||
© 2019 American Physical Society. Deterministic current-induced spin-orbit torque (SOT) switching of magnetization in a heavy transition metal/ferromagnetic metal/oxide magnetic heterostructure with the ferromagnetic layer being perpendicularly magnetized typically requires an externally applied in-plane field to break the switching symmetry. We show that by inserting an in-plane magnetized ferromagnetic layer CoFeB underneath the conventional W/CoFeB/MgO SOT heterostructure, deterministic SOT switching of the perpendicularly magnetized top CoFeB layer can be realized without the need of in-plane bias field. Kerr imaging study further unveils that the observed switching is mainly dominated by domain nucleation and domain wall motion, which might limit the potentiality of using this type of multilayer stack design for nanoscale SOT-MRAM application. Comparison of the experimental switching behavior with micromagnetic simulations reveals that the deterministic switching in our devices cannot be explained by the stray field contribution of the in-plane magnetized layer, and the roughness-caused Néel coupling effect might play a more important role in achieving the observed field-free deterministic switching.
|Appears in Collections:||材料科學與工程學系|
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