Lattice expansion in islands stabilized by electron confinement: Ag on Si(111)-7x7
| Title | Lattice expansion in islands stabilized by electron confinement: Ag on Si(111)-7x7 |
| Publication Type | Journal Article |
| Year of Publication | 2010 |
| Authors | Unal B, Belianinov A, Thiel PA, Tringides MC |
| Journal Title | Physical Review B |
| Volume | 81 |
| Pages | 085411 |
| Date Published | 02/01 |
| ISBN Number | 1098-0121 |
| Accession Number | ISI:000275053300109 |
| Keywords | ag/si(111), diffraction, films, growth, LOW-TEMPERATURE, photoemission, quantum-well states, surfaces, thickness, x-ray |
| Abstract | Ag on Si(111)-7x7 was one of the first systems where height selection of metal islands was attributed to electron confinement, i.e., stabilization of selected heights through a quantum size effect (QSE). However, it has been puzzling how the requisite electron standing waves can form, because the Fermi level E-F (along the growth [111] direction) is within the gap for bulk Ag. With detailed experiments over a wide coverage and temperature range, we show that a large increase of 12% is present in the interlayer spacing within the bilayer islands. This can shift E-F below the gap, allowing electron confinement to control height selection. This conclusion is also supported by the observation of a corrugation pattern of period 3 nm on top of the Ag islands, which is bias dependent and can only be the result of QSE-generated standing waves normal to the film. |
| URL | <Go to ISI>://000275053300109 |
| DOI | 10.1103/Physrevb.81.085411 |
