Title: Investigation of the Dzyaloshinskii-Moriya interaction and room temperature skyrmions in W/CoFeB/MgO thin films and microwires

Abstract

Recent studies have shown that material structures, which lack structural inversion symmetry and have high spin-orbit coupling can exhibit chiral magnetic textures and skyrmions which could be a key component for next generation storage devices. The Dzyaloshinskii-Moriya Interaction (DMI) that stabilizes skyrmions is an anti-symmetric exchange interaction favoring non-collinear orientation of neighboring spins. It has been shown that materials systems with high DMI can lead to very efficient domain wall and skyrmion motion by spin-orbit torques. To engineer such devices, it is important to quantify the DMI for a given material system. Here, we extract the DMI at the Heavy Metal/Ferromagnet interface using two complementary measurement schemes, namely, asymmetric domain wall motion and the magnetic stripe annihilation. By using the two different measurement schemes, we find for W(5 nm)/Co₂₀Fe₆₀B₂₀(0.6 nm)/MgO(2 nm) the DMI to be 0.68 ± 0.05 mJ/m² and 0.73 ± 0.5 mJ/m², respectively. Furthermore, we show that this DMI stabilizes skyrmions at room temperature and that there is a strong dependence of the DMI on the relative composition of the CoFeB alloy. Finally, we optimize the layers and the interfaces using different growth conditions and demonstrate that a higher deposition rate leads to a more uniform film withmore » reduced pinning and skyrmions that can be manipulated by spin orbit torques.« less

Authors:

Jaiswal, S. ^[1]; Litzius, K. ^[2]; Lemesh, I. ^[3]; Büttner, F. ^[3]; Finizio, S. ^[4]; Raabe, J.  ^[4];

• Search DOE PAGES for author "Raabe, J."
• Search DOE PAGES for ORCID "0000-0002-2071-6896"

Weigand, M. ^[5]; Lee, K. ^[6]; Langer, J.  ^[7];

• Search DOE PAGES for author "Langer, J."
• Search DOE PAGES for ORCID "0000-0002-6319-8259"

Ocker, B.  ^[7];

• Search DOE PAGES for author "Ocker, B."
• Search DOE PAGES for ORCID "0000-0002-3546-5110"

Jakob, G.  ^[8];

• Search DOE PAGES for author "Jakob, G."
• Search DOE PAGES for ORCID "0000-0001-9466-0840"

Beach, G. S. D. ^[3]; Kläui, M. ^[8]

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+ Show Author Affiliations

1. Johannes Gutenberg Univ., Mainz (Germany); Singulus Technologies AG, Kahl am Main (Germany)
2. Johannes Gutenberg Univ., Mainz (Germany); Graduate School of Excellence, Mainz (Germany); Max Planck Inst. for Intelligent Systems, Stuttgart (Germany)
3. Massachusetts Inst. of Technology (MIT), Cambridge, MA (United States)
4. Paul Scherrer Inst. (PSI), Villigen (Switzerland). Swiss Light Source
5. Max Planck Inst. for Intelligent Systems, Stuttgart (Germany)
6. Johannes Gutenberg Univ., Mainz (Germany)
7. Singulus Technologies AG, Kahl am Main (Germany)
8. Johannes Gutenberg Univ., Mainz (Germany); Graduate School of Excellence, Mainz (Germany)

Publication Date:

Thu Jul 13 00:00:00 EDT 2017

Research Org.:

Massachusetts Inst. of Technology (MIT), Cambridge, MA (United States)

Sponsoring Org.:

USDOE Office of Science (SC)

OSTI Identifier:

1535323

Grant/Contract Number:  

SC0012371

Resource Type:

Accepted Manuscript

Journal Name:

Applied Physics Letters

Additional Journal Information:

Journal Volume: 111; Journal Issue: 2; Journal ID: ISSN 0003-6951

Publisher:

American Institute of Physics (AIP)

Country of Publication:

United States

Language:

English

Subject:

36 MATERIALS SCIENCE; Physics