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Domain Structure and Wall Dynamics in High-PMA NiCo<sub>2</sub>O<sub>4</sub> Thin Films

POSTER

Abstract

The inverse-spinel room-temperature ferrimagnetic NiCo2O4 (NCO) is of increasing interest, due to its demonstrated large perpendicular magnetic anisotropy, sensitivity of magnetic behavior to mixed cation valence, and deviations from ideal inverse spinel stoichiometry. Among the important information still missing about this material’s magnetic behavior from the literature includes information about the exchange interaction and domain structure of the magnetized film.

In this talk, we present data on temperature-dependent domain structure of thin film NiCo2O4 on MgAl2O4 (NCO/MAO) using XMCD-PEEM from the Advanced Light Source BL 11.0.1.1. The results show that magnetic domain sizes remain constant across a wide range of temperatures, which indicates strong pinning of the domains. Additionally, the resolution of XMCD-PEEM is sufficient to measure the domain wall widths, from which the micromagnetic exchange stiffness can be extracted. The exchange stiffness is up to an order of magnitude larger than similar materials with PMA, further solidifying NCO as an option in room-temperature magnetic applications.

Presenters

  • Corbyn Mellinger

    University of Nebraska - Lincoln

Authors

  • Corbyn Mellinger

    University of Nebraska - Lincoln

  • Guanhua Hao

    University of Nebraska - Lincoln

  • Xiao Wang

    Physics, Bryn Mawr College, Bryn Mawr College, Department of Physics, Bryn Mawr College

  • Xuemei Cheng

    Bryn Mawr College, Department of Physics, Bryn Mawr College

  • Rajesh Chopdekar

    Lawrence Berkeley National Lab, Lawrence Berkeley Natl Lab, Advanced Light Source, Lawrence Berkeley National Laboratory, Lawrence Berkeley National Laboratory, Advance Light Source, Lawrence Berkeley National Laboratory

  • Xiaoshan Xu

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