C Rogero | PubMed Health

PubMed2006

Structure of rutile TiO2 (110)-(1 x 2): formation of Ti2O3 quasi-1D metallic chains.

Combining STM, LEED, and density functional theory, we determine the atomic surface structure of rutile TiO2 (110)-(1 x 2): nonstoichiometric Ti2O3 stripes along the [001] direction. LEED patterns are sharp and free of streaks, while STM images show monatomic steps, wide terraces, and no cross-links. At room temperature, atoms in the Ti2O3 group have large amplitudes of vibration. The long quasi-1D chains display metallic character, show no interaction between them, and cannot couple to bulk or surface states in the gap region, forming good atomic wires.

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PubMed2001

Probing interface electronic structure with overlayer quantum-well resonances: Al/Si(111).

The dispersion of quantum-well resonances in ultrathin epitaxial Al films on Si(111) reveals energy- and wave vector-dependent reflection properties at the Al/Si interface. The substrate electronic structure strongly influences the phase shift of the electron waves upon reflection at the interface. Thus the details of the substrate electronic structure need to be taken into account for a complete analysis of metallic quantum-well resonances. Furthermore, the assumption of loss of parallel wave vector information upon reflection or transmission through a lattice-mismatched interface is challenged. The changes induced in the electronic structure of the overlayer can be used to probe the ground-state substrate band edges.

Journal Article↗