Print Email Facebook Twitter Structural, electronic, and magnetic properties of iron carbide Fe7C3 phases from first-principles theory Title Structural, electronic, and magnetic properties of iron carbide Fe7C3 phases from first-principles theory Author Fang, C.M. Van Huis, M.A. Zandbergen, H.W. Faculty Applied Sciences Department Kavli Institute of Nanoscience Date 2009-12-22 Abstract The iron carbide Fe7C3 exhibits two types of basic crystal structures, an orthorhombic (o-) form and a hexagonal (h-) one. First-principles calculations have been performed for the basic Fe7C3 forms and for the related ?-Fe3C cementite phase. Accurate total-energy calculations show that the stability of Fe7C3 is comparable to that of ?-Fe3C. The o-Fe7C3 phase is more stable than the hexagonal one, in contrast to recent atomistic simulations. Furthermore, the calculations also show a rather low energy for a carbon vacancy in the o structure, which implies possible C deficiency in the lattice. Both Fe7C3 phases are ferromagnetic metals. Electronic band-structure calculations show that all Fe atoms exhibit high-spin states with the majority of their 3d states being almost fully occupied. From an analysis of the structural and energetic properties, the formation of the o phase in steel treatment processes and of h form in carburization of ferrite is discussed. To reference this document use: http://resolver.tudelft.nl/uuid:1b721891-b305-41c2-96ca-f1aacacbb153 Publisher American Physical Society ISSN 0163-1829 Source Physical Review B, 80 (22), 2009 Part of collection Institutional Repository Document type journal article Rights (c) 2009 The Authors ; American Physical Society Files PDF Fang_2009.pdf 450.26 KB Close viewer /islandora/object/uuid:1b721891-b305-41c2-96ca-f1aacacbb153/datastream/OBJ/view