Exploring new phases of Fe3-xCoxC for rare-earth-free magnets

S. Q. Wu, B. Balamurugan, X. Zhao, S. Yu, Manh Cuong Nguyen, Y. Sun, S. R. Valloppilly, D. J. Sellmyer, K. M. Ho, C. Z. Wang

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3 Scopus citations

Abstract

Structures, magnetic moments, and magnetocrystalline anisotropy energies of the Fe3-xCoxC intermetallic compounds are systematically investigated using adaptive genetic algorithm (AGA) crystal-structure predictions and first-principles calculations. Besides reproducing the known cementite (Pnma) structure of Fe3C, i.e. x = 0, the AGA searches also capture several new metastable phases within the room-temperature range. In particular, a bainite (P6322) structure exhibits the largest magnetic moment among all low-energy structures, and its energy is only 4 meV/atom higher than the cementite (Pnma) phase. The atomic structure of the Pnma Fe2CoC phase, i.e. x = 1, is also identified, and the calculated x-ray diffraction spectrum, magnetocrystalline anisotropy energy, and saturation magnetization based on the structure from our theoretical study are in good agreement with experiment.

Original languageEnglish (US)
Article number215005
JournalJournal of Physics D: Applied Physics
Volume50
Issue number21
DOIs
StatePublished - May 9 2017

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Keywords

  • first-principles calculation
  • magnetic properties
  • rare-earth free
  • structure prediction

ASJC Scopus subject areas

  • Electronic, Optical and Magnetic Materials
  • Condensed Matter Physics
  • Acoustics and Ultrasonics
  • Surfaces, Coatings and Films

Cite this

Wu, S. Q., Balamurugan, B., Zhao, X., Yu, S., Nguyen, M. C., Sun, Y., Valloppilly, S. R., Sellmyer, D. J., Ho, K. M., & Wang, C. Z. (2017). Exploring new phases of Fe3-xCoxC for rare-earth-free magnets. Journal of Physics D: Applied Physics, 50(21), [215005]. https://doi.org/10.1088/1361-6463/aa6b85