Analysis of Scanning Tunneling Microscope Topographs of Graphite Surfaces Roughened by Ar+ Ion Bombardment

1989 ◽  
Vol 157 ◽  
Author(s):  
Elliott A. Eklund ◽  
R. Stanley Williams ◽  
Eric J. Snyder

ABSTRACTThe scanning tunneling microscope (STM) has been used to investigate graphite surfaces roughened by 5 keV Ar+ ion bombardment. The (0001) surfaces of several samples were etched with the same total ion dose but with different sputter rates for each surface. STM images taken after sputtering show that the roughness of the sputtered surfaces depended on the sputter rate and that the surface topography of each sample appeared self-similar over a large range of length scales. These experimental observations agree with predictions of the recently proposed Shadow Model. The two dimensional height-height correlation function is utilized as a means of quantitative analysis for STM topographs of sputtered surfaces.

1996 ◽  
Vol 4 (2) ◽  
pp. 3-4
Author(s):  
Stephen W. Carmichael

The process of ultra-miniaturization has been termed nanofabrication. It looks like the scanning tunneling microscope (STU) and related microscopes will be players in this technology of the future. One of the most recent contributions has been the demonstration that single molecules can be “pushed” across a surface with the STM. This remarkable achievement was demonstrated by Thomas Jung, Reto Schlittler, and James Gimzewski of the IBM Zurich Research Laboratory and Hao Tang and Christian Joachim of the National Center for Scientific Research in Toulouse, They were able to position intact individual molecules on a two-dimensional surface at room temperature by a controlled “pushing” action of the tip of a STM. Similar positioning feats have been done at low temperatures while thermal motion is limited.


1992 ◽  
Vol 286 ◽  
Author(s):  
Teresa D. Golden ◽  
Ryne P. Raffaelle ◽  
Richard J. Phillips ◽  
Jay A. Switzer

ABSTRACTWe have imaged fractured cross-sections of electrodeposited ceramic oxides based on the TI-Pb-O system using a scanning tunneling microscope. The goal of this work is to measure both the modulation wavelength and compositional profile of the superlattices by mapping out the electronic properties in real space on a nanometer scale. Fourier analysis was done on STM images of all superlattices to yield the modulation wavelength. The modulation wavelength from STM was then compared with those obtained, by Faraday calculation and x-ray diffraction. The STM can be used to design “better” superlattices. We have found that the composition profile in superlattices deposited by modulating the potential was more square than in superlattices deposited by modulating the current.


1985 ◽  
Vol 56 (11) ◽  
pp. 2168-2170 ◽  
Author(s):  
H. Jonathon Mamin ◽  
David W. Abraham ◽  
Eric Ganz ◽  
John Clarke

2009 ◽  
Vol 1177 ◽  
Author(s):  
Danny Eric Paul Vanpoucke ◽  
Geert Brocks

AbstractNanowire (NW) arrays form spontaneously after high temperature annealing of a sub monolayer deposition of Pt on a Ge(001) surface. These NWs are a single atom wide, with a length limited only by the underlying beta-terrace to which they are uniquely connected. Using ab-initio density functional theory (DFT) calculations we study possible geometries of the NWs and substrate. Direct comparison to experiment is made via calculated scanning tunneling microscope (STM) images. Based on these images, geometries for the beta-terrace and the NWs are identified, and a formation path for the nanowires as function of increasing local Pt density is presented. We show the beta-terrace to be a dimer row surface reconstruction with a checkerboard pattern of Ge-Ge and Pt-Ge dimers. Most remarkably, comparison of calculated to experimental STM images shows the NWs to consist of germanium atoms embedded in the Pt-lined troughs of the underlying surface, contrary to what was assumed previously in experiments.


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