Anomalous Hall effect in epitaxial spinel NiCo2O4 films

ORAL

Abstract

We report the magnetotransport studies of the spinel ferrimagnetic NiCo2O4 (NCO) thin films. NCO has an inverse spinel structure with the Neel temperature TN above room temperature. We deposited epitaxial NCO films as thin as 2 u.c. (~1.6 nm) on (001) MgAl2O4 substrates using off-axis magnetron sputtering, with high crystallinity and atomically smooth surface achieved. The NCO films possess an out-of-plane magnetic easy axis. A robust anomalous Hall effect (AHE) has been observed at the temperature range from 2 K to TN of 330 K, which changes sign at ~190 K. We discuss the possible mechanisms that determine the AHE signal in the NCO films. Our study reveals the complex energy landscape in NCO due to the competition of the crystalline field with the charge and spin degrees of freedom.

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Presenters

  • Xuegang Chen

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

Authors

  • Xuegang Chen

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

  • Xiaozhe Zhang

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

  • Xiaoshan Xu

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

  • Xia Hong

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