DIFFRACTION SPOT PROFILE ANALYSIS FOR VICINAL SURFACES WITH LONG-RANGE ORDER

The concept of diffraction spot analysis established for non-vicinal s urfaces with long-range order (finite RMS-roughness due to finite numb er of exposed layers) has been applied to vicinal surfaces. In contras t to vicinal surfaces with short-range order investigated previously w here the spots show a splitting into broadened satellites. here, the s atellites consist of a sharp central spot and a diffuse shoulder. We d emonstrate that the RMS-roughness of the vicinal surface can be extrac ted from the attenuation of tile sharp central spot and the island siz e distribution from the halfwidth of the shoulder. The diffraction spo t analysis has been applied to a vicinal Pd(100) surface. Supposing id entical terrace length distributions correlation effects on tile diffr action pattern are discussed. (C) 1998 Elsevier Science B.V.