Ankara : The Department of Physics and the Institute of Graduate Studies of Bilkent Univ. , 1988.Thesis (Master's) -- Bilkent University, 1988.Includes bibliographical references leaves 93-99.The Scanning Tunneling Microscope is proven to be one of the most
powerful tools for surface structure determination. Present theories are able to
explain the operation of the microscope when the tip is far from the surface. For
the small tip height case the atomic-scale interaction of the tip and the surface
has to be included in the theory. The electronic structure of the combined
system of the tip and the surface is calculated with an Empirical Tight Binding
approach for graphite. It is found that in the vicinity of the tip some Tip
Induced Localized States are formed. These states play an important role in
the tunneling phenomenon. The contribution of these states to the tunneling
current is calculated.Tekman, Ahmet ErkanM.S