Determination of the (3x3)-Sn/Ge(111) structure by photoelectron diffraction

Details Determination of the (3x3)-Sn/Ge(111) structure by photoelectron diffraction Determination of the (3x3)-Sn/Ge(111) structure by photoelectron diffraction

2000-12-11

arxiv.org/abs/cond-mat/0012179v2

Phys. Rev. B, 63 (2001) 115406

Physics

Condensed Matter

Strongly Correlated Electrons

10 pages with 9 figures, added references

Scientific paper

10.1103/PhysRevB.63.115406

At a coverage of about 1/3 monolayer, Sn deposited on Ge(111) below 550 forms a metastable (sqrt3 x sqrt3)R30 phase. This phase continuously and reversibly transforms into a (3x3) one, upon cooling below 200 K. The photoemission spectra of the Sn 4d electrons from the (3x3)-Sn/Ge(111) surface present two components which are attributed to inequivalent Sn atoms in T4 bonding sites. This structure has been explored by photoelectron diffraction experiments performed at the ALOISA beamline of the Elettra storage ring in Trieste (Italy). The modulation of the intensities of the two Sn components, caused by the backscattering of the underneath Ge atoms, has been measured as a function of the emission angle at fixed kinetic energies and viceversa. The bond angle between Sn and its nearest neighbour atoms in the first Ge layer (Sn-Ge1) has been measured by taking polar scans along the main symmetry directions and it was found almost equivalent for the two components. The corresponding bond lengths are also quite similar, as obtained by studying the dependence on the photoelectron kinetic energy, while keeping the photon polarization and the collection direction parallel to the Sn-Ge1 bond orientation (bond emission). A clear difference between the two bonding sites is observed when studying the energy dependence at normal emission, where the sensitivity to the Sn height above the Ge atom in the second layer is enhanced. This vertical distance is found to be 0.3 Angstroms larger for one Sn atom out of the three contained in the lattice unit cell. The (3x3)-Sn/Ge(111) is thus characterized by a structure where the Sn atom and its three nearest neighbour Ge atoms form a rather rigid unit that presents a strong vertical distortion with respect to the underneath atom of the second Ge layer.

Affiliated with

Also associated with

No associations

Rating

Determination of the (3x3)-Sn/Ge(111) structure by photoelectron diffraction does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.

If you have personal experience with Determination of the (3x3)-Sn/Ge(111) structure by photoelectron diffraction, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Determination of the (3x3)-Sn/Ge(111) structure by photoelectron diffraction will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFWR-SCP-O-149190