Real-Space Imaging of Nanoscale Electrodeposited Ceramic Superlattices in the Scanning Tunneling Microscope

1992 ◽  
Vol 286 ◽  
Author(s):  
Teresa D. Golden ◽  
Ryne P. Raffaelle ◽  
Richard J. Phillips ◽  
Jay A. Switzer
Keyword(s):  
Cross Sections ◽  
Scanning Tunneling Microscope ◽  
Real Space ◽  
Scanning Tunneling ◽  
Nanometer Scale ◽  
X Ray Diffraction ◽  
Ceramic Oxides ◽  
Tunneling Microscope ◽  
Stm Images ◽  
Modulation Wavelength

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.

Nanometer‐scale hole formation on graphite using a scanning tunneling microscope

1989 ◽  
Vol 55 (17) ◽  
pp. 1727-1729 ◽  
Author(s):  
T. R. Albrecht ◽  
M. M. Dovek ◽  
M. D. Kirk ◽  
C. A. Lang ◽  
C. F. Quate ◽  
...  
Keyword(s):  
Scanning Tunneling Microscope ◽  
Scanning Tunneling ◽  
Nanometer Scale ◽  
Hole Formation ◽  
Tunneling Microscope

Scanning Tunneling Microscope-Induced Luminescence Studies of Defects in GaN Layers and Heterostructures

1999 ◽  
Vol 588 ◽  
Author(s):  
S. Evoy ◽  
C. K. Harnett ◽  
S. Keller ◽  
U. K. Mishra ◽  
S. P. DenBaars ◽  
...  
Keyword(s):  
Quantum Wells ◽  
Scanning Tunneling Microscope ◽  
Multiple Quantum Well ◽  
Scanning Tunneling ◽  
Nanometer Scale ◽  
Multiple Quantum ◽  
Proof Of Concept ◽  
Cross Sectional ◽  
Tunneling Microscope ◽  
Nm Range

AbstractWe present the scanning tunneling microscope-induced luminescence (STL) imaging of defects in optoelectronic materials. Resolution is first discussed using cross-sectional images of InGaAs/GaAs quantum dots. Proof of concept is then provided through the nanometer-scale imaging of GaN layers and quantum wells. The expected λ=356±25 nm range dominates the low temperature STL of GaN. Mapping of luminescence shows circular non-emitting areas around threading dislocations. Extent of dark areas suggests a hole diffusion length of Ld=30–55 nm, in agreement with reported values. The expected λ=450±35 nm range dominates the STL from a buried InGaN/GaN multiple quantum well. Imaging reveals 30–100 nm wide smooth fluctuations of luminescence.

Nanometer‐scale modification and characterization of lead‐telluride surface by scanning tunneling microscope at 4.2 K

1996 ◽  
Vol 79 (5) ◽  
pp. 2435-2438
Author(s):  
D. N. Davydov ◽  
Yu. B. Lyanda‐Geller ◽  
S. A. Rykov ◽  
H. Hancotte ◽  
R. Deltour ◽  
...  
Keyword(s):  
Scanning Tunneling Microscope ◽  
Lead Telluride ◽  
Scanning Tunneling ◽  
Nanometer Scale ◽  
Tunneling Microscope

scholarly journals The Formation of Self-Assembled Nanowire Arrays on Ge(001): a DFT Study of Pt Induced Nanowire Arrays

2009 ◽  
Vol 1177 ◽  
Author(s):  
Danny Eric Paul Vanpoucke ◽  
Geert Brocks
Keyword(s):  
Scanning Tunneling Microscope ◽  
Density Functional ◽  
Nanowire Arrays ◽  
Single Atom ◽  
Scanning Tunneling ◽  
Checkerboard Pattern ◽  
High Temperature Annealing ◽  
Functional Theory ◽  
Tunneling Microscope ◽  
Stm Images

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.

Application of various modes of scanning-probe microscopies in polymer systems

1996 ◽  
Vol 54 ◽  
pp. 196-197
Author(s):  
Dale J. Meier
Keyword(s):  
Scanning Tunneling Microscope ◽  
Molecular Level ◽  
Contact Forces ◽  
Scanning Probe ◽  
Scanning Tunneling ◽  
Nanometer Scale ◽  
Polymer Systems ◽  
Tunneling Microscope ◽  
Atomic Force ◽  
Cantilever Probe

The invention of the scanning tunneling microscope (STM) by Binnig and Rohrer in 1982 demonstrated an unparalleled ability to image materials at the sub-nanometer scale. The invention rapidly lead to an explosion of applications of STM in a wide variety of fields. However, imaging by an STM is essentially limited to materials which are conductive, or could be made conductive, so many materials of interest could not be imaged by STM. This limitation was removed a few years later (1985) by the invention of the atomic force microscope (AFM) by Binnig, Quate and Gerber, in which imaging is based on the response of a soft cantilever beam to the contact forces between an ultra-fine probe tip and a sample. The cantilever/probe systems could be made sensitive enough to enable the AFM to easily resolve atomic or molecular level features.

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