Iridium-modified Si(111) surface

The physical and electronic properties of Ir-modified Si(111) surface have been investigated with the help of STM (scanning tunneling microscopy) and LEED (low energy electron diffraction). The LEED pattern of the surface exhibits ?reconstruction. STM images show that ?? reconstruction originates from the Ir-ring clusters. STS (scanning tunneling spectroscopy) measurements on the ring clusters reveal a state located about 0.3?eV below the Fermi level. A careful analysis shows that this state originates from ??domains of Ir-modified Si(111) surface.