Surface core-level photoelectron diffraction from Si dimers at the Si(001)- (2×1) surface

Intensity variations of the dimer derived surface shifted Si 2p core level from single domain Si(001)- (2×1) have been measured as a function of azimuthal angle. Comparisons to multiple scattering calculations show that such measurements provide a method for determining the structural origins of surface shifted core levels. In addition, a structural analysis illustrates the sensitivity of this method to the detailed structure around the emitting atoms. In this case, a determination of the surface geometry indicates that the dimer bond is tilted 19.0°with respect to the surface.