Strain effect on electronic and structural properties of metal nanoislands grown on reconstructed Au(111)

Add to your list(s) Download to your calendar using vCal

• Guido Fratesi, Materials Science Department, Milano-Bicocca University, Milan, Italy
• Wednesday 13 April 2011, 11:30-12:30
• Mott Seminar Room, Cavendish Laboratory, Department of Physics.

If you have a question about this talk, please contact Stephen Walley.

The growth of various metal elements on the Au(111) surface is characterized by an initial ordered island nucleation at the elbows of the surface herringbone reconstruction, where shorter lattice constant affects the energetics and electronic properties of the adsorbates. Here we focus on Fe and Pd on Au(111), investigated by combining scanning tunneling microscopy and spectroscopy experiments (STM/STS) and density functional theory simulations (DFT).

A characteristic peak measured in the electron local density of states of Fe/Au(111) at Fermi level indicates the presence of a nondispersive minority Fe dz2 state, while less prominent contributions to the LDOS are predicted from the Au(111) surface state upon hybridization with the overlayer Fe states. The peak energy was measured to shift from occupied to unoccupied states as a function of position within Fe islands. We related this effect to the reconstruction-induced local Fe-Fe bond length variation [1].

The assignment of atom-size features, observed by STM close to herringbone elbows at low Pd coverage, to adsorbed, substituted, or subsurface Pd atoms is sometimes disputed in the literature, and here addressed by DFT simulations. The low activation barriers computed for the diffusion of adsorbed Pd, and bias-dependent contrast in simulated tunneling currents following attenuation of the Au(111) sp-surface state, support the interpretation of black spots observed in STM as subsurface Pd atoms, rather than on-surface ones [2].

[1] F. Donati, G. Fratesi, A. Mairov, M. Passoni, C.S. Casari, C.E. Bottani, M.I. Trioni, and A. Li Bassi, Phys. Rev. B (2011) in press

[2] G. Fratesi, J. Phys.: Condens. Matter 23, 015001 (2011)

This talk is part of the Physics and Chemistry of Solids Group series.

This talk is included in these lists:

• All Cavendish Laboratory Seminars
• All Talks (aka the CURE list)
• Centre for Health Leadership and Enterprise
• Featured lists
• ME Seminar
• Mott Seminar Room, Cavendish Laboratory, Department of Physics
• Neurons, Fake News, DNA and your iPhone: The Mathematics of Information
• Physics and Chemistry of Solids Group
• School of Physical Sciences
• Thin Film Magnetic Talks

Note that ex-directory lists are not shown.