High resolution LEED studies of surface misorientation and incommensurate domain walls on reconstructed Pt(110) surface

Abstract

Using the unique capability of the high-resolution LEED, we can precisely measure the Bragg peak positions and angular profiles of electron diffraction beams scattered from a crystal surface. The observations reported here relate to a reconstructed Pt(110)(1 × 2) surface at room temperature. Oscillations of the Bragg peak position and periodic variations of the FWHM of both the superlattice and integral beams along the reciprocal rods over a wide range of energies have been studied. The oscillation of the peak position of the superlattice beam results from phase shifts of electrons scattering from incommensurate (1 × 2) reconstruction domain walls between adjacent terraces. On the other hand, the oscillation of the integral-order beam is due to a surface misorientation. Furthermore, the periodic variation of the FWHM of the superlattice beam is dominated by the degree of surface misorientations. However, the periodic variation of the FWHM associated with the integral beam results mainly from the existence of steps. Comparing the measurements with an existing model we have estimated the degree of the surface misorientation, the distribution of the incommensurate domain walls, and the lateral incommensurability on the Pt(110)(l × 2) surface.