Personal Web Site
0124 PIERCE HALL
University of California
Riverside, CA 92521
(951) 827-2041 (Voice)
(951) 827-4713 (Fax)
Professor of Chemistry
- College of Natural and Agricultural Sciences
- Vordiplom Berlin, Germany 1991
- Freie Universität,
- Diploma Th Berlin, Germany 1995
- Fritz-Haber-Institute of the
- Doctor Rer Berlin, Germany 1997
- Freie Universität
- Postdoctor Berlin, Germany 1997
- Postdoctor New York 1998
- Columbia University
2002 NSF Early Career Development Program
1998 Ramsauer Award
I am presently setting up a Scanning Tunneling Microscope (STM) for the investigation of molecular adsorption on metal surfaces. STM allows to image individual atoms and molecules on metal and semiconductor surfaces. The spatial expansion of specific electronic states of surfaces can also directly be visualized. This allows to gain valuable information on how surface reactions occur and assists in the design of dedicated catalysts.
Scanning Tunneling Microscopy is based on scanning a sharp tip less than a nanometer (10E-9 m) above a surface while applying a small bias of a few mV to a few V. Using the resultant tunneling current as a feedback signal this allows to measure the substrate contour at a resolution of a few picometer (10E-12 m). However, an STM cannot only be used to acquire images of atoms, molecules and bare surfaces, but also to manipulate and modify them.
Using the STM tip extreme electric fields and currents can be applied simultaneously to a single spots of a surfaces and individual molecules adsorbed there. This allows to study properties of adsorbates under otherwise not easy to access conditions. Especially, the excitation of chemical reactions of molecules like dissociation, association, desorption from the substrate, diffusion on the substrate, island formation etc. can be investigated.
Precise knowledge about techniques to move molecules on surfaces and to make them undergo reactions might allow the assembly of organic molecules on surfaces step-by-step out of individual building blocks. Recent findings suggest the possibility of the synthesis of biphenyl out of iodobenzene according to the Ullmann reaction scheme.
Optical excitation of molecules offers an alternative way of studying their reaction mechanisms. While this method is primarily spatially non-resolved, using ultra-short laser pulses time resolution far beyond the atomic movement can be achieved. Using scanning probe techniques or alignment with THz pulses some spatial resolution can be recovered - even in the liquid phase.
. Hla S W, Bartels L, Meyer G, Rieder K-H, Single Molecule Engineering: Synthesis of Individual Biphenyl Molecules with the STM Tip. submitted to Nature
. Bartels L, Kuehnle A, Hla S W, Meyer G, Rieder K-H, Manson J R, Scanning Tunneling Microscopy observations of a one dimensional electronic edge state at steps on Cu(111). submitted to Physical Review Letters
. Shan J, Weling A S, Knoesel E, Bartels L, Bonn M, Nahata A, Reider G A, Heinz T F, Single-shot measurement of terahertz electromagnetic pulses by use of electro-optic sampling, Optics Letters, vol 25., no. 6, 15 Mar. 2000, pp.426-8.
. Bartels L, Wolf M, Klammroth T, Saalfrank P, Kuehnle A, Meyer G, Rieder K-H, Atomic scale chemistry: Desorption of ammonia from Cu(111) induced by tunneling electrons. Chemical Physics Letters, vol. 313, 12 Nov. 1999, pp. 544-52
. Bartels L, Meyer G, Rieder K-H, The evolution of CO adsorption on Cu(111) as studied with bare and CO-functionalized scanning tunneling tips. Surface Science Letters, vol. 432 ( 1999) L621–L626
. Bartels L, Meyer G, Rieder K-H. High-resolution spectroscopy of weakly chemisorbed species using a low-temperature scanning tunneling microscope (STM): CO/Cu(111). Chemical Physics Letters, vol.297, no.3-4, 27 Nov. 1998, pp.287-92.
. Bartels L, Wolf M, Meyer G, Rieder K-H. On the diffusion of `hot' adsorbates: a non-monotonic distribution of single particle diffusion lengths for CO/Cu (111). Chemical Physics Letters, vol.291, no.5-6, 24 July 1998, pp.573-8.
. Bartels L, Meyer G, Rieder K-H. Atomic hop-scotch: different manipulation modes of single Cu atoms on Cu(111). Chemical Physics Letters, vol.285, no.3-4, 20 March 1998, pp.284-7.
. Bartels L, Meyer G, Rieder K-H, Velic D, Knoesel E, Hotzel A, Wolf M, Ertl G. Dynamics of electron-induced manipulation of individual CO molecules on Cu(111). Physical Review Letters, vol.80, no.9, 2 March 1998, pp.2004-7
. Bartels L, Meyer G, Rieder K-H. Basic steps involved in the lateral manipulation of single CO molecules and rows of CO molecules. Chemical Physics Letters, vol.273, no.5-6, 25 July 1997, pp.371-5.
. Bartels L, Meyer G, Rieder K-H. Basic steps of lateral manipulation of single atoms and diatomic clusters with a scanning tunneling microscope tip. Physical Review Letters, vol.79, no.4, 28 July 1997, pp.697-700.
. Bartels L, Meyer G, Rieder K-H. Controlled vertical manipulation of single CO molecules with the scanning tunneling microscope: a route to chemical contrast. Applied Physics Letters, vol.71, no.2, 14 July 1997, pp.213-15.
. Meyer G, Bartels L, Zophel S, Henze E, Rieder K-H. Controlled atom by atom restructuring of a metal surface with the scanning tunneling microscope. Physical Review Letters, vol.78, no.8, 24 Feb. 1997, pp.1512-15.
. Bartels L, Zophel S, Meyer G, Henze E, Rieder K-H. Dimer formation and surface alloying: a STM study of lead on Cu(211). Surface Science, vol.372, no.1-3, 10 Feb. 1997, pp.L261-5.
Articles and Conference Proceedings
. Meyer G, Bartels L, Rieder K-H, Atom manipulation with the scanning tunneling microscope: nanostructuring and femtochemistry, Superlattices & Microstructures, vol.25, no.1-2, 1999, pp.463-71.
. Meyer G, Bartels L, Rieder K-H, Atom manipulation with the scanning tunneling microscope: nanostructuring and femtochemistry, Japanese Journal Appl. Phys., vol.37, no.12B, Dec. 1998, pp.7143-7.
. Meyer G, Bartels L, Zophel S, Rieder K-H, Lateral manipulation of adatoms and native substrate atoms with the low-temperature scanning tunneling microscope, Applied Physics, vol.A68, no.2, Feb. 1999, pp.125-9.
. Witte G, Braun J, Nowack D, Bartels L, Neu B, Meyer G. Oxygen-induced reconstructions on Cu(211). Physical Review B-Condensed Matter, vol.58, no.19, 15 Nov. 1998, pp.13224-32.
. Meyer G, Bartels L, Zophel S, Rieder K-H. Possibilities for atom by atom restructuring of surfaces employing native substrate atoms as well as foreign species. Applied Surface Science, vol.130-132, June 1998, pp.527-33.
. Bartels L, Meyer G, Rieder K-H. Lateral manipulation of single Cu atoms on flat and stepped copper surfaces. Journal of Vacuum Science & Technology A-Vacuum Surfaces & Films, vol.16, no.3, May-June 1998, pp.1047-9.
. Neuhold G, Bartels L, Paggel JJ, Horn K. Thickness-dependent morphologies of thin Ag films on GaAs(110) as revealed by LEED and STM. Surface Science, vol.376, no.1-3, 10 April 1997, pp.1-12.