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Description:

Perpendicular magnetic anisotropy (PMA) induced at the interface of the metallic magnetic layer/oxide layer plays a major role in scaling of state-of-the-art spin-transfer-torque magnetoresistive random access memory. The realization of PMA requires the development of mature interface manipulation techniques, as well as materials constituting the interface. Herein, we report large PMA using stacks developed with an ultrathin (~0.7 nm) Fe/rock-salt CrO(001) interface via an oxygen-driven diffusion process. The stacks were prepared by sputter-deposition and post-annealing of the Cr buffer/ultrathin Fe/MgO structure. Significant oxidation of the Fe layer and Cr diffusion into the MgO layer occurred during the deposition. After post-annealing, the oxidized Fe layer was reduced to form an Fe/rock-salt-type Cr-monoxide structure due to chemical layer exchange. The lattice-matched Fe/CrO interface with a large interfacial PMA energy of 1.55 mJ/m2 was confirmed after annealing at 500degreeC. X-ray absorption spectroscopy measurements revealed that the post-annealing promoted the redox reaction from the Fe oxide to the metallic Fe and the formation of the CrO. The observed PMA indicates that the oxygen-driven diffusion process by annealing resulted in the well-controlled Fe/CrO interface. The demonstrated diffusion process provides a new chemical route to fabricate artificial, well-controlled PMA interfaces, even containing metastable materials, beyond the conventional sequential layer stacking for the development of spintronic devices.

Rights:

• Creative Commons BY Attribution 4.0 International
  

Keyword: spintronics, perpendicular magnetic anisotropy, CrO, epitaxial growth

Date published: 2024-11-01

Publisher: AIP Publishing

Journal:

• APL Materials (ISSN: 2166532X) vol. 12 issue. 11

Funding:

• Japan Society for the Promotion of Science 16H06332
• New Energy and Industrial Technology Development Organization JPNP16007
• Japan Society for the Promotion of Science 22H04966
• Japan Society for the Promotion of Science 23K26535
• Japan Society for the Promotion of Science 24H00408
• the Photon Factory Program Advisory Committee, KEK 2021G069

Manuscript type: Publisher's version (Version of record)

MDR DOI:

First published URL: https://doi.org/10.1063/5.0233103

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Updated at: 2024-12-10 16:55:28 +0900

Published on MDR: 2024-12-10 16:55:28 +0900