Stability, structure and electronic properties of gamma-Fe23C6 from first principles theory

C Fang, MA van Huis, MHF Sluiter, HW Zandbergen

    Research output: Contribution to journalArticleScientificpeer-review

    71 Citations (Scopus)

    Abstract

    First-principles' calculations of GGA and GGA - U type have been performed for gamma-Fe23C6, a complex iron carbide with 116 atom in the unit cell GGA results were found to be in better agreement with experimental data than GGA + U results Various occupancies for Wyckoff positions and corresponding magnetic orderings have been explored Our calculations reveal that the crystal structure is composed of a framework of strongly linked Fe atoms, and additional stabilizing Fe and C atoms positioned in cavities The local electronic and magnetic properties vary strongly among the non-equivalent Fe sites in gamma-Fe23C6 The lattice parameters of gamma-Fe23C6 match those of austenite well Surprisingly, pure gamma-Fe23C6 is found to be more stable than commonly occurring theta-Fe3C cementite Moreover, the calculations show low vacancy energy (about 0 37 eV) for Fe at 4a sites in gamma-Fe23C6 Conditions of formation and factors hampering the formation of gamma-Fe23C6 in steel manufacturing processes are discussed
    Original languageUndefined/Unknown
    Pages (from-to)2968-2977
    Number of pages10
    JournalActa Materialia
    Volume58
    Issue number8
    DOIs
    Publication statusPublished - 2010

    Keywords

    • academic journal papers
    • CWTS JFIS >= 2.00

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