scholarly journals An in situ nanoindentation specimen holder for a high voltage transmission electron microscope

Author(s):  
M. A. Wall ◽  
U. Dahmen
2005 ◽  
Vol 20 (7) ◽  
pp. 1814-1824 ◽  
Author(s):  
Martin Bartsch ◽  
Peter Schall ◽  
Michael Feuerbacher ◽  
Ulrich Messerschmidt

Decagonal single quasicrystals of the composition Al70Ni15Co15have been deformed in situ in a high-voltage transmission electron microscope at 730 °C along the 10-fold periodic axis to directly observe the dislocation motion. The deformation is carried by stress-assisted climb of dislocations with periodic Burgers vectors. These dislocations may also glide and move by a combination of glide and climb. Dislocations with Burgers vectors with components in the periodic and quasiperiodic directions probably move under the action of a chemical force. The observations are interpreted by a model established by P. Schall et al. under consideration of the activation parameters of macroscopic deformation and by analogies with the behavior of icosahedral quasicrystals.


Author(s):  
M.A. O’Keefe ◽  
J. Taylor ◽  
D. Owen ◽  
B. Crowley ◽  
K.H. Westmacott ◽  
...  

Remote on-line electron microscopy is rapidly becoming more available as improvements continue to be developed in the software and hardware of interfaces and networks. Scanning electron microscopes have been driven remotely across both wide and local area networks. Initial implementations with transmission electron microscopes have targeted unique facilities like an advanced analytical electron microscope, a biological 3-D IVEM and a HVEM capable of in situ materials science applications. As implementations of on-line transmission electron microscopy become more widespread, it is essential that suitable standards be developed and followed. Two such standards have been proposed for a high-level protocol language for on-line access, and we have proposed a rational graphical user interface. The user interface we present here is based on experience gained with a full-function materials science application providing users of the National Center for Electron Microscopy with remote on-line access to a 1.5MeV Kratos EM-1500 in situ high-voltage transmission electron microscope via existing wide area networks. We have developed and implemented, and are continuing to refine, a set of tools, protocols, and interfaces to run the Kratos EM-1500 on-line for collaborative research. Computer tools for capturing and manipulating real-time video signals are integrated into a standardized user interface that may be used for remote access to any transmission electron microscope equipped with a suitable control computer.


2011 ◽  
Vol 284-286 ◽  
pp. 2026-2036 ◽  
Author(s):  
Pedro Alejandro Tamayo Meza ◽  
Pablo Schabes Retchkiman ◽  
Luis Armando Flores Herrera ◽  
Viacheslav A. Yermishkin ◽  
Carlos F. Ordáz Yañez ◽  
...  

A high dose of electron irradiation generates amorphous zones with critical vacancy concentrations in the pyrographite. The degree of disorder “” of amorphization of Graphite, natural graphite, pyrographite and polycrystal pyrographite are analyzed as a function of time “t”, and the amorphization kinetics under different voltages inside the HVTEM.


Author(s):  
M.L. McDonald ◽  
J.M. Gibson

Interest in ultrahigh vacuum (UHV) specimen environments in the transmission electron microscope (TEM) has grown considerably in recent years. The possibility of in-situ studies of atomically clean surfaces has been demonstrated by Yagi et.al., Wilson & Petroff & others. Most designs have involved a side entry specimen holder with cryopumping in the pole piece and are not easily compatible with ultrahigh resolution(UHR) due to size and stability requirements. We have designed a differentially pumped UHV specimen chamber for the JEOL 200CX (UHRTEM). It is intended to allow examination of clean thin specimens at pressures below 10-9 torr with a point to point resolution of 2.5 Å. Provisions for in-situ heating, cooling & deposition have been made. A unique part of this design is the relatively large volume sample chamber held at UHV (figsl&2). This design allows characterization of the atmosphere to which the sample is exposed & cleaning & preparation of samples out of the pole piece which is believed to be necessary for UHRTEM. Another possibility with this design is the transfer of a sample into the TEM from other chambers by use of a transfer case without exposing the sample to an atmosphere above 10-9 torr. Extra ports have been provided to accommodate future experiments.


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