Control of Spin Chirality and Anomalous Hall Effect in Noncollinear Antiferromagnetic Mn3NiN Epitaxial Thin Films

ORAL

Abstract

Antiferromagnets with emergent anomalous Hall effect establish new directions for spintronic applications, with faster switching dynamics compared to ferromagnetic counterparts. The noncollinear antiferromagnet Mn3NiN, providing a unique combination of metallic resistivity and anomalous Hall effect via Berry phase mechanisms, is a promising candidate. We have grown high-quality epitaxial Mn3NiN thin films on (001) LSAT substrates via reactive magnetron sputtering. Below the 240 K Neel temperature, these films show an anomalous hall effect significantly larger than conventional ferromagnets, understood through their non-vanishing Berry curvature arising from the Γ4g-type noncollinear antiferromagnetic spin arrangement. In addition, a small tetragonality induces a net magnetic moment that couples to external magnetic fields, providing control of the Γ4g antiferromagnetic state. We demonstrated this control through a varying film tetragonality established by the N2 fraction during reactive growth, verified by measurements of the anomalous hall resistivity. Mn3NiN provides an ideal structural strain controlled platform for anomalous Hall effect based spintronics applications.

* CBE acknowledges support for this research through the Vannevar Bush Faculty Fellowship (ONR N00014-20-1-2844). Magnetic and transport measurements at the University of Wisconsin–Madison were supported by the US Department of Energy (DOE), Office of Science, Office of Basic Energy Sciences (BES), under award number DE-FG02-06ER46327.

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Presenters

  • Yuchuan Yao

    University of Wisconsin - Madison

Authors

  • Yuchuan Yao

    University of Wisconsin - Madison

  • Pratap Pal

    University of Wisconsin-Madison, Department of Materials Science and Engineering, University of Wisconsin-Madison, Wisconsin 53706, USA

  • Neil G Campbell

    University of Wisconsin - Madison

  • Mark S Rzchowski

    University of Wisconsin-Madison, University of Wisconsin - Madison

  • Chang-Beom Eom

    University of Wisconsin-Madison, Department of Materials Science and Engineering, University of Wisconsin-Madison, Madison, WI 53706, USA, University of wisconsin-madison, Department of Materials Science and Engineering, University of Wisconsin-Madison, Wisconsin 53706, USA