STM investigation of energetic insertion during direct ion deposition

2001 ◽  
Vol 672 ◽  
Author(s):  
Joshua M. Pomeroy ◽  
Aaron Couture ◽  
Joachim Jacobsen ◽  
Barbara H. Cooper ◽  
J.P. Sethna ◽  
...  
Keyword(s):  
Scanning Tunneling Microscope ◽  
Low Temperatures ◽  
Md Simulation ◽  
Kinetic Monte Carlo ◽  
Scanning Tunneling ◽  
Surface Films ◽  
Copper Films ◽  
Tunneling Microscope ◽  
Precise Control ◽  
Ion Deposition

ABSTRACTThin copper films have been deposited on single crystal copper substrates and characterized using a UHV Scanning Tunneling Microscope to probe the effect of atomic insertions during hyperthermal ion deposition. At low temperatures, atomic insertions are predicted to provide a net downhill current that offsets the roughening effect due to uphill “Schwoebel” currents leading to a net smoothing of the surface. Films have been grown at several different energies targeted to observe a crossover from insertion driven smoothing to adatom-vacancy dominated roughening. Copper thin films are deposited near 20 eV using a mass selected ion deposition system that allows precise control (+/− 2 eV) over the energy of constituent atoms. Experimental observations are compared with a sophisticated Kinetic Monte Carlo and Molecular Dynamics hybrid (KMC-MD) simulation.

scholarly journals A “Pushy” Microscope

1996 ◽  
Vol 4 (2) ◽  
pp. 3-4
Author(s):  
Stephen W. Carmichael
Keyword(s):  
Scanning Tunneling Microscope ◽  
Low Temperatures ◽  
Research Laboratory ◽  
Room Temperature ◽  
Scientific Research ◽  
Thermal Motion ◽  
Scanning Tunneling ◽  
Two Dimensional ◽  
Tunneling Microscope ◽  
Dimensional Surface

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.

scholarly journals Development of a cryogenic system for a UHV manipulator for a light detection device in a LT-STM.

2019 ◽  
Author(s):  
Ronaldo Rodrigues Fernandes Vieira ◽  
Luiz Fernando Zagonel ◽  
Yves Maia Auad
Keyword(s):  
Low Temperature ◽  
Scanning Tunneling Microscope ◽  
Low Temperatures ◽  
Thermal Instability ◽  
High Vacuum ◽  
Ultra High Vacuum ◽  
Cryogenic System ◽  
Scanning Tunneling ◽  
Tunneling Microscope ◽  
Temperature Scanning

This project aims to develop a cryogenic system for a UHV (Ultra-High Vacuum) manipulator that is currently under development in our group and that will be installed inside a low temperature scanning tunneling microscope (LT-STM). This advice will be used as a light detector to collect the Luminescence in the STM scan, and since the equipment will operate in low temperatures, it is necessary that this advice also operate in low temperatures so that it won't cause thermal instability which would prefent image acquisition due to thermal drifts.

MEASUREMENT OF CRITICAL EXPONENTS OF PLATINUM THIN FILMS

2003 ◽  
Vol 10 (01) ◽  
pp. 1-5 ◽  
Author(s):  
M. C. SALVADORI ◽  
L. L. MELO ◽  
M. CATTANI ◽  
O. R. MONTEIRO ◽  
I. G. BROWN
Keyword(s):  
Thin Films ◽  
Critical Exponents ◽  
Scanning Tunneling Microscope ◽  
Growth Dynamics ◽  
Scanning Tunneling ◽  
Silicon Substrates ◽  
Tunneling Microscope ◽  
Metal Plasma ◽  
Ion Deposition

We have fabricated platinum thin films by metal plasma ion deposition on silicon substrates. The roughness of these films has been measured by a scanning tunneling microscope (STM) and we have determined the growth dynamics critical exponents.

scholarly journals Development of a light detector for a low temperature scanning tunneling microscope

2019 ◽  
Author(s):  
Luiza Lober de Souza Piva ◽  
Luiz Fernando Zagonel ◽  
Yves Maia Auad
Keyword(s):  
Low Temperature ◽  
Scanning Tunneling Microscope ◽  
Low Temperatures ◽  
Detection System ◽  
Scanning Tunneling ◽  
Parabolic Mirror ◽  
Tunneling Microscope ◽  
Nanostructured Semiconductors ◽  
Temperature Scanning ◽  
Optical Fiber Bundle

This project aims to implement, test and improve a light detection system that will be installed in a Scanning Tunneling Microscope operating at Low Temperatures (LT-STM). This system is made of a parabolic mirror, a converging lens and an optical fiber bundle. The challenge will be to aligning these elements with sub-micrometric precision and develop alignment protocols to align the mirror with respect to the tunnel junction. Such procedures are crucial to the Young Investigators Project that funds the purchase of the LT-STM and which the final objective is the study of the luminescence of nanostructured semiconductors.

scholarly journals STM characterization of Cu thin films grown by direct ion deposition

2000 ◽  
Vol 648 ◽  
Author(s):  
Joshua M. Pomeroy ◽  
Aaron Couture ◽  
Joachim Jacobsen ◽  
Colin C. Hill ◽  
James P. Sethna ◽  
...  
Keyword(s):  
Thin Films ◽  
Surface Roughness ◽  
Kinetic Monte Carlo ◽  
Scanning Tunneling ◽  
Metal Thin Films ◽  
Precise Control ◽  
Beneficial Effects ◽  
Insertion Mechanism ◽  
Analysis System ◽  
Ion Deposition

AbstractIn certain cases, the incidence energy of constituent atoms activates an atomistic insertion mechanism, which decreases the surface roughness of metal thin films. In an effort to probe this effect, homoepitaxial copper films were grown using a mass/energy selected direct ion deposition technique that allows precise control of the incidence energy. Surface roughness is measured using a Scanning Tunneling Microscope (STM) within the same UHV surface analysis system. The activation of the insertion mechanism near 20 eV triggers smoother crystal growth. The beneficial effects begin to be obscured by adatom/vacancy creation near 30 eV. A sophisticated Kinetic Monte Carlo/Molecular Dynamics (KMC-MD) model supports this interpretation.

Scanning tunneling microscopy of E. coli RNA polymerase deposited onto an Au substrate by an electrochemical process

1991 ◽  
Vol 49 ◽  
pp. 378-379
Author(s):  
Rebecca W. Keller ◽  
Carlos Bustamante ◽  
David Bear
Keyword(s):  
Scanning Tunneling Microscope ◽  
Biological Sample ◽  
Substrate Surface ◽  
Electrochemical Process ◽  
Atomic Resolution ◽  
Scanning Tunneling ◽  
Tunneling Microscopy ◽  
Tunneling Microscope ◽  
E Coli ◽  
Preparation Techniques

Under ideal conditions, the Scanning Tunneling Microscope (STM) can create atomic resolution images of different kinds of samples. The STM can also be operated in a variety of non-vacuum environments. Because of its potentially high resolution and flexibility of operation, it is now being applied to image biological systems. Several groups have communicated the imaging of double and single stranded DNA.However, reproducibility is still the main problem with most STM results on biological samples. One source of irreproducibility is unreliable sample preparation techniques. Traditional deposition methods used in electron microscopy, such as glow discharge and spreading techniques, do not appear to work with STM. It seems that these techniques do not fix the biological sample strongly enough to the substrate surface. There is now evidence that there are strong forces between the STM tip and the sample and, unless the sample is strongly bound to the surface, it can be swept aside by the tip.

STM of freeze-fracture replicas: Problems and promises

1993 ◽  
Vol 51 ◽  
pp. 68-69
Author(s):  
J. T. Woodward ◽  
J. A. N. Zasadzinski
Keyword(s):  
Scanning Tunneling Microscope ◽  
Organic Materials ◽  
Freeze Fracture ◽  
Atomic Resolution ◽  
Scanning Tunneling ◽  
Tunneling Microscope ◽  
Molecular Scale ◽  
Organic Surfaces ◽  
Metal Layers ◽  
Conductive Surfaces

The Scanning Tunneling Microscope (STM) offers exciting new ways of imaging surfaces of biological or organic materials with resolution to the sub-molecular scale. Rigid, conductive surfaces can readily be imaged with the STM with atomic resolution. Unfortunately, organic surfaces are neither sufficiently conductive or rigid enough to be examined directly with the STM. At present, nonconductive surfaces can be examined in two ways: 1) Using the AFM, which measures the deflection of a weak spring as it is dragged across the surface, or 2) coating or replicating non-conductive surfaces with metal layers so as to make them conductive, then imaging with the STM. However, we have found that the conventional freeze-fracture technique, while extremely useful for imaging bulk organic materials with STM, must be modified considerably for optimal use in the STM.

The atomic-force microscope and its future in biology

1993 ◽  
Vol 51 ◽  
pp. 704-705
Author(s):  
Jean-Paul Revel
Keyword(s):  
Silicon Nitride ◽  
Laser Beam ◽  
Atomic Force Microscope ◽  
Scanning Tunneling Microscope ◽  
Point Of View ◽  
Scanning Tunneling ◽  
Close Relative ◽  
Tunneling Microscope ◽  
Atomic Force ◽  
Sharp Point

The last few years have been marked by a series of remarkable developments in microscopy. Perhaps the most amazing of these is the growth of microscopies which use devices where the place of the lens has been taken by probes, which record information about the sample and display it in a spatial from the point of view of the context. From the point of view of the biologist one of the most promising of these microscopies without lenses is the scanned force microscope, aka atomic force microscope.This instrument was invented by Binnig, Quate and Gerber and is a close relative of the scanning tunneling microscope. Today's AFMs consist of a cantilever which bears a sharp point at its end. Often this is a silicon nitride pyramid, but there are many variations, the object of which is to make the tip sharper. A laser beam is directed at the back of the cantilever and is reflected into a split, or quadrant photodiode.

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