Magnetic Properties of Ferromagnetic Cobalt Grown in an Applied Magnetic Field

ORAL

Abstract

Preparation of cobalt crystals from a melt requires temperatures above its Curie temperature, TC = 1394 K, meaning the nucleation and growth will occur in the paramagnetic state. In this work, a sulfur flux was used and the liquidus was shifted as low as 1150 K [1], thereby allowing crystal formation in the ferromagnetic phase. A magnetic field, Bsyn = 0, 3 T, or 9 T, was applied during synthesis, and the resulting polycrystalline samples were characterized with XRD and magnetometry, which provided magnetization data, M(5 K ≤ T ≤ 300 K, B = 10 mT) and M(T = 5 K or 300 K, −1 T ≤ B ≤ 7 T), with B oriented parallel and perpendicular to the growth axis which was along Bsyn. Overall, our data are consistent with magnetism reported for single crystals [2,3]. However, the remnant magnetization was found to increase with the magnitude of Bsyn, while trends in other magnetic properties, such as the maximum value of magnetization and the coercive field, were not as clearly established. Our results demonstrate using a sulfur flux allows for nucleation and growth of cobalt crystals below TC while preserving known magnetic properties.

[1] X. Lin, S.L. Bud’ko, P.C. Canfield, Philos. Mag. 92 (2012) 2436, doi:10.1080/14786435.2012.671552.

[2] S. Kaya, Sci. Rep. Tohoku Univ. 17 (1928) 1157.

[3] K. Honda, M. Masumoto, Sci. Rep. Tohoku Univ. 20 (1931) 323.

*This work was supported, in part, by the NSF REU via DMR-1708410 and DMR-1852138, DMR-1644779 (MagLab), and the State of Florida. Synthesis was funded by DOE EERE AMO DE-EE000913. The views expressed herein do not necessarily represent the views of the DOE or any agency thereof.

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Presenters

  • Caeli L Benyacko

    • Dept. of Physics and MagLab, University of Florida

Authors

  • Caeli L Benyacko

    • Dept. of Physics and MagLab, University of Florida

  • Steven Flynn

    • Dept. of Physics and MagLab, University of Florida

  • Jared C Lee

    • Dept. of Physics, University of Florida

  • Fuyan Ma

    • Dept. of Chemistry, University of Florida

  • Khalil A Abboud

    • Dept. of Chemistry, University of Florida

  • Mark W Meisel

    • Dept. of Physics and MagLab, University of Florida

  • James J Hamlin

    • University of Florida
    • Dept. of Physics, University of Florida