OBSERVATION OF NEW 2-DIMENSIONAL PERIODIC STRUCTURES IN THE CONFINED REGIONS OF THE RECONSTRUCTED PT(100) SURFACE

New 2D periodic structures have been observed by STM in the regions of the reconstructed Pt(100) surface which are confined by domain bounda ries or lattice steps. These structures can be seen only in a very nar row energy window near the Fermi level, and they are strongly correlat ed to the original atomic arrangements of the surface. These structure s arise most probably from a modification in the distribution of the e lectronic density of states which is strongly coupled to the ion cores of the surface to produce a periodic shift in the atomic rearrangemen ts in order to minimize the strain and free energy of the surface.