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Title: Current-induced spin-orbit torque switching of perpendicularly magnetized Hf|CoFeB|MgO and Hf|CoFeB|TaO{sub x} structures

Journal Article · · Applied Physics Letters
DOI:https://doi.org/10.1063/1.4919108· OSTI ID:22398931
 [1]; ; ; ; ; ; ;  [1];  [2]
  1. Department of Electrical Engineering, University of California, Los Angeles, California 90095 (United States)
  2. Department of Physics, University of Çukurova, Adana 01330 (Turkey)

We study the effect of the oxide layer on current-induced perpendicular magnetization switching properties in Hf|CoFeB|MgO and Hf|CoFeB|TaO{sub x} tri-layers. The studied structures exhibit broken in-plane inversion symmetry due to a wedged CoFeB layer, resulting in a field-like spin-orbit torque (SOT), which can be quantified by a perpendicular (out-of-plane) effective magnetic field. A clear difference in the magnitude of this effective magnetic field (H{sub z}{sup FL}) was observed between these two structures. In particular, while the current-driven deterministic perpendicular magnetic switching was observed at zero magnetic bias field in Hf|CoFeB|MgO, an external magnetic field is necessary to switch the CoFeB layer deterministically in Hf|CoFeB|TaO{sub x}. Based on the experimental results, the SOT magnitude (H{sub z}{sup FL} per current density) in Hf|CoFeB|MgO (−14.12 Oe/10{sup 7} A cm{sup −2}) was found to be almost 13× larger than that in Hf|CoFeB|TaO{sub x} (−1.05 Oe/10{sup 7} A cm{sup −2}). The CoFeB thickness dependence of the magnetic switching behavior, and the resulting  H{sub z}{sup FL} generated by in-plane currents are also investigated in this work.

OSTI ID:
22398931
Journal Information:
Applied Physics Letters, Vol. 106, Issue 16; Other Information: (c) 2015 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA); ISSN 0003-6951
Country of Publication:
United States
Language:
English