[Events] MSSI Research Forum 2010

[Emily.Barrett]

Materials  &  Surface  Science  Institute

Research  Forum  2010

 

 


PRESENTATION  BY


Professor Philip Moriarty

University of Nottingham

 

TITLE  OF  PRESENTATION

 

Toggling Bistable Atomic Switches: Non-Contact Atomic Force Microscopy
Manipulation of Si(100) Surface Dimers

 


ABSTRACT


The Si(100) surface is an excellent example of a simple system which
exhibits remarkably rich physics. Although the fundamental building
block of the surface, the silicon dimer, is well understood, there has
been a significant amount of debate regarding the arrangements of dimers
which form various surface phases on Si(100). Indeed, it is only
relatively recently that the ground state of the surface has been
conclusively elucidated. 

 

A key aspect of the Si(100) surface dimer is its propensity to buckle,
i.e. to distort from a planar to a non-planar configuration where one
silicon atom moves away from the surface while the other moves closer.
In this talk I shall discuss how the qPlus variant of non-contact atomic
force microscopy (operating at 5K and under ultrahigh vacuum conditions)
can be used not only to image Si(100) surface phases but, by controlling
the tip-surface interaction, to flip individual dimers from one buckled
configuration to the other. Force-distance spectra extracted from the
experimental data enable a measurement of the force required to toggle
the dimer and, via a measurement of the damping of the qPlus tuning fork
oscillation, the dissipation associated with the dimer configuration
flip has been ascertained. 

 


ABOUT  THE  PRESENTER


 

Prof. Moriarty is Professor of Physics and EPSRC Fellow in the School of
Physics & Astronomy, University of Nottingham, and is a recently
appointed Adjunct Professor to the Department of Physics, UL. He has
authored/co-authored 87 refereed papers including a frequently-cited
invited review article on nanostructured materials. His research spans
topical themes in nanometre scale science including far-from-equilibrium
processes in self-assembly, single molecule manipulation and
spectroscopy, electronic structure and transport in nanoparticle arrays,
and synchrotron-based investigations of nanostructured and molecular
systems. 

 

 

DATE:            Wednesday, 10 February 2010

TIME:            12h00

VENUE:         MSB-012 MSSI Building

 

 


REFRESHMENTS  WILL  BE  PROVIDED  AT  11h45


For further information, please contact:

Dr Teresa Curtin, Tel. No:  (061) 202981 or Email:  teresa.curtin at ul.ie 

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