A controversy concerning the nature of the surfaces of Fe3O4(001) and γ-Fe2O3(001), grown onto MgO(001) by molecular beam epitaxy, was considered. Despite claims to the contrary, it was shown that γ-Fe2O3(001) unambiguously exhibited a (1 x 1) surface net, in contrast to Fe3O4(001), which assumed a reconstruction. In addition, high-energy-resolution Fe 2p and O 1s core-level photoelectron spectra obtained at both normal and grazing emission were presented for γ-Fe2O3(001) and Fe3O4(001). These spectra showed that the Fe3O4(001) surface had a higher Fe(III)/Fe(II) ratio than did the bulk, and that the asymmetry in the O 1s line shape for Fe3O4(001) was due to final state effects rather than to the presence of a surface oxygen or hydroxyl species.

Surface Termination, Composition and Reconstruction of Fe3O4(001) and γ-Fe2O3(001). S.A.Chambers, S.A.Joyce: Surface Science, 1999, 420[2-3], 111-22