Electron Microscopy of Single Molecules

1999 ◽  
Vol 589 ◽  
Author(s):  
D.E. Luzzi ◽  
B.W. Smith
Keyword(s):  
Electron Microscopy ◽  
Carbon Nanotubes ◽  
Threshold Energy ◽  
Irradiation Damage ◽  
High Signal ◽  
Signal To Noise ◽  
Reaction Chambers ◽  
The Stability ◽  
Noise Observation

AbstractWe report on the imaging of single C60 molecules adsorbed on the surface of carbon nanotubes. In the course of the work, the efficacy of carbon nanotubes as substrates for the high signal-to-noise observation of molecules is examined. The stability of nanotubes as a function of temperature, chemical environment and irradiation environment is explored. Carbon nanotubes are found to have a threshold energy for ballistic irradiation damage of approximately 85 keV. Finally, the use of nanotubes as in-situ reaction chambers and for other in-situ experimentation is demonstrated.

Encapsulated Fullerenes Within Single Wall Carbon Nanotubes

1999 ◽  
Vol 5 (S2) ◽  
pp. 182-183
Author(s):  
Brian W. Smith ◽  
David E. Luzzi
Keyword(s):  
Electron Microscopy ◽  
Carbon Nanotubes ◽  
Pulsed Laser ◽  
Irradiation Damage ◽  
Laser Vaporization ◽  
Single Wall Carbon Nanotubes ◽  
Phase Object ◽  
Parallel Lines ◽  
Weak Phase ◽  
Transmission Electron

It is well documented that the pulsed laser vaporization of graphite produces both carbon nanotubes and C60 in the presence of certain metallic catalysts. In nanotube production most of the Ceo is removed along with other residual contaminants during succeeding purification and annealing steps. The possibility of C60 becoming trapped inside a nanotube during this elaborate sequence has been considered but not previously detected.Nanotubes are observed with high resolution transmission electron microscopy under conditions chosen to minimize both exposure time and irradiation damage. Since a nanotube satisfies the weak phase object approximation, its image is a projection of the specimen -potential in the direction of the electron beam. The image has maximum contrast where the beam encounters the most carbon atoms, which occurs where it is tangent to the tube’s walls. Thus, the image consists of two dark parallel lines whose separation is equal to the tube diameter, 1.4 nm.

Electron Microscopy of Nanodevices: In Situ and Ex Situ Characterization of Structure and Transport Properties of Carbon Nanotubes

2008 ◽  
Vol 14 (S2) ◽  
pp. 188-189
Author(s):  
JM Zuo ◽  
T Kim ◽  
Q Chen ◽  
LM Peng ◽  
EA Olson
Keyword(s):  
Electron Microscopy ◽  
Carbon Nanotubes ◽  
New Mexico ◽  
Transport Properties ◽  
Ex Situ

Extended abstract of a paper presented at Microscopy and Microanalysis 2008 in Albuquerque, New Mexico, USA, August 3 – August 7, 2008

Augmentation of the step-by-step Energy-Scanning EXAFS beamline BL-09 to continuous-scan EXAFS mode at INDUS-2 SRS

2016 ◽  
Vol 23 (6) ◽  
pp. 1518-1525 ◽  
Author(s):  
Ashwini Kumar Poswal ◽  
Ankur Agrawal ◽  
Himanshu Kumar Poswal ◽  
Dibyendu Bhattacharyya ◽  
Shambhu Nath Jha ◽  
...  
Keyword(s):  
Signal To Noise Ratio ◽  
Energy Calibration ◽  
Acquisition Time ◽  
High Signal ◽  
Signal To Noise ◽  
Double Crystal ◽  
Time Resolved ◽  
Synchrotron Source ◽  
Double Crystal Monochromator

An innovative scheme to carry out continuous-scan X-ray absorption spectroscopy (XAS) measurements similar to quick-EXAFS mode at the Energy-Scanning EXAFS beamline BL-09 at INDUS-2 synchrotron source (Indore, India), which is generally operated in step-by-step scanning mode, is presented. The continuous XAS mode has been implemented by adopting a continuous-scan scheme of the double-crystal monochromator and on-the-fly measurement of incident and transmitted intensities. This enabled a high signal-to-noise ratio to be maintained and the acquisition time was reduced to a few seconds from tens of minutes or hours. The quality of the spectra (signal-to-noise level, resolution and energy calibration) was checked by measuring and analysing XAS spectra of standard metal foils. To demonstrate the energy range covered in a single scan, a continuous-mode XAS spectrum of copper nickel alloy covering both Cu and NiK-edges was recorded. The implementation of continuous-scan XAS mode at BL-09 would expand the use of this beamline inin situtime-resolved XAS studies of various important systems of current technological importance. The feasibility of employing this mode of measurement for time-resolved probing of reaction kinetics has been demonstrated byin situXAS measurement on the growth of Ag nanoparticles from a solution phase.

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