The stoichiometric recovery and accompanying changes of subsurface atomic structure of Ar ion sputtered, oxygen deficient a-Fe2O3(0001) are studied with X-ray scattering. Although oxygen annealing up to 735 C results in a stoichiometric top surface layer manifested as a (1 · 1) surface structure, the X-ray scattering reveals the existence of a non-stoichiometric phase in the subsurface region. ...
