Structure-Property relationship for H covered Fe3O4(001)

Magnetite(Fe3O4), the oldest permanent magnet, is still attracting intense studies due to its fascinating surface physical properties. Previous LEED and STM experiments have reported reconstruction on Fe3O4(001) clean surface, but the origin of this reconstruction is still under debate. Hydrogen removes this reconstruction. LEED, HREELS, XPS are used to study the hydrogen induced surface properties. Surface geometry change was investigated by LEED-I(V) calculation and the structure refinements are being done now. XPS experiments show evidences of OH species on the hydrogen-covered surface, which is consistent with HREELS data, proving H adatoms are bonded to the surface oxygen sites. This suggested the ratio of Fe2$+$/Fe3$+$ on the surface is increased. This change is observed by Fe 2p peak shift in XPS spectra. We will discuss the role hydrogen played in the surface structure and physical properties change induced by reconstruction.