Experimental Surface Science
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Research in surface physics at Tufts centers on understanding the interactions of atoms and molecules with metal surfaces. We employ a range of analytical techniques, including low-energy electron diffraction (LEED), Auger electron spectroscopy (AES), and temperature-programmed desorption (TPD), but our emphasis is on surface infrared spectroscopy and electrical resistance measurements. |
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One current focus is on the effects of
adsorption (the binding of atoms or molecules to the surface) on electronic
conduction in metals. By localizing some electrons and providing scattering
centers for others, adsorbed gases can have a significant effect on the
electrical resistance and optical reflectance of thin metal films. These
effects are relevant to gas sensing and may play an important role in the
microscopic origins of friction. Our studies have shown that current models
of these effects are inadequate, and may help to guide future theoretical
development. We are also beginning a project to explore adsorption on
metallic quantum wells. In a collaboration
with the Center for Sensor Materials
at For more information, please see our Surface Physics web site. Selected
Publications: "Unusual
adsorption kinetics of formic acid on Cu(100) studied
by dc resistance and nonresonant infrared reflectance changes," C.-L.
Hsu, E.F. McCullen and R.G. Tobin, Surface Science 542, 120 (2003). "A
surface-science-based model for the selectivity of platinum-gold electrodes
in zirconia-based NOx sensors," D.C. Skelton, R.G. Tobin,
D.K. Lambert, C.L. DiMaggio and G.B. Fisher, Sensors and Actuators B: Chemical 96, 46 (2003). "Mechanisms
of adsorbate-induced surface resistivity – experimental and theoretical
developments," R.G. Tobin, Surface Science 502-503, 374 (2002). |
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