Observation of Topological Hall Effect and Magnetic Textures in Ferrimagnetic (110) NiCo2O4 Films

ORAL

Abstract

We report the observation of topological Hall effect (THE) and magnetic textures in 16 nm (110) NiCo2O4 (NCO) films. Epitaxial NCO films are deposited on (110) MgAl2O4 (MAO) substrates via off-axis RF magnetron sputtering. The films are ferrimagnetic with Curie temperature TC above 370 K and possess in-plane magnetic anisotropy. The saturation magnetization is about 2.2 μB/formula unit. We observe anomalous Hall effect (AHE) in out-of-plane magnetic field H, which exhibits negligible hysteresis and saturates at the high magnetic fields. Below 100 K, prominent THE signal occurs within a narrow magnetic field range close to where AHE saturates. At 4 K, magnetic force microscopy (MFM) imaging shows magnetic bubble domains with an average size of 150 nm emerge at H = 3.0-3.7 kOe, which correlates well with the magnetic field range for the THE. The gradient of the bubble domain suggests the existence of magnetic textures. We also compare the THE and MFM data with the magnetization hysteresis (M-H) curves. Our results suggest the emergence of spin bimerons/merons as the spins rotate from in-plane to out-of-plane orientations in (110) NCO film.

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Presenters

  • Kun Wang

    University of Nebraska - Lincoln, Department of Physics and Astronomy & Nebraska Center for Materials and Nanoscience, University of Nebraska-Lincoln, Department of Physics and Astronomy & Nebraska Center for Materials and NanoscienceUniversity of Nebraska - Lincoln, Physics and Astronomy, University of Nebraska-Lincoln

Authors

  • Kun Wang

    University of Nebraska - Lincoln, Department of Physics and Astronomy & Nebraska Center for Materials and Nanoscience, University of Nebraska-Lincoln, Department of Physics and Astronomy & Nebraska Center for Materials and NanoscienceUniversity of Nebraska - Lincoln, Physics and Astronomy, University of Nebraska-Lincoln

  • Qiuchen Wu

    University of Nebraska - Lincoln, Department of Physics and Astronomy & Nebraska Center for Materials and Nanoscience, University of Nebraska-Lincoln, Department of Physics and Astronomy & Nebraska Center for Materials and NanoscienceUniversity of Nebraska - Lincoln, Physics and Astronomy, University of Nebraska-Lincoln

  • Xuegang Chen

    Department of Physics and Astronomy & Nebraska Center for Materials and Nanoscience, University of Nebraska-Lincoln

  • Xia Hong

    Physics and Astronomy, University of Nebraska-Lincoln, Department of Physics and Astronomy & Nebraska Center for Materials and Nanoscience, University of Nebraska-Lincoln