NEW CHARGE-DENSITY MODULATIONS IN CONFINED REGIONS OF RECONSTRUCTED PT(100) SURFACE

In the narrow regions confined by lattice steps or domain boundaries o f the reconstructed Pt(100) surface, new periodic structures have been observed with the scanning tunneling microscopy. These structures cor relate well, or are commensurate, with the atomic structure of the ori ginal reconstructed surface. They can also be shown to arise from a re distribution of the electronic density of states. Thus, these charge d ensity waves are produced by strongly coupled electrons and phonons, b ut are enhanced by the quantum confinement effect of the barriers. Suc h structures can also be induced near a domain boundary due to the str ain of artificially created nanometer-size holes. Therefore we believe that coupling originates from the strain relief effect of the system reducing its strain and electronic energy.