scholarly journals In situ experiments in the new transmission electron microscopes

1993 ◽  
Vol 4 (2-3) ◽  
pp. 111-117 ◽  
Author(s):  
J. Pelissier ◽  
P. Debrenne
1991 ◽  
Vol 235 ◽  
Author(s):  
Charles W. Allen

ABSTRACTMotivated at least initially by materials needs for nuclear reactor development, extensive irradiation effects studies employing transmission electron microscopes (TEM) have been performed for several decades, involving irradiation-induced and irradiation-enhanced microstructural changes, including phase transformations such as precipitation, dissolution, crystallization, amorphization, and order-disorder phenomena. From the introduction of commercial high voltage electron microscopes (HVEM) in the mid-1960s, studies of electron irradiation effects have constituted a major aspect of HVEM application in materials science. For irradiation effects studies two additional developments have had particularly significant impact; (1) the development of TEM specimen holders in which specimen temperature can be controlled in the range 10–2200 K and (2) the interfacing of ion accelerators which allows in situ TEM studies of irradiation effects and the ion beam modification of materials within this broad temperature range. This paper treats several aspects of in situ studies of electron and ion beam-induced and enhanced phase changes and presents two case studies involving in situ experiments performed in an HVEM to illustrate the strategies of such an approach of the materials research of irradiation effects.


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.


Author(s):  
Kenneth S. Vecchio ◽  
John A. Hunt

In-situ experiments conducted within a transmission electron microscope provide the operator a unique opportunity to directly observe microstructural phenomena, such as phase transformations and dislocation-precipitate interactions, “as they happen”. However, in-situ experiments usually require a tremendous amount of experimental preparation beforehand, as well as, during the actual experiment. In most cases the researcher must operate and control several pieces of equipment simultaneously. For example, in in-situ deformation experiments, the researcher may have to not only operate the TEM, but also control the straining holder and possibly some recording system such as a video tape machine. When it comes to in-situ fatigue deformation, the experiments became even more complicated with having to control numerous loading cycles while following the slow crack growth. In this paper we will describe a new method for conducting in-situ fatigue experiments using a camputer-controlled tensile straining holder.The tensile straining holder used with computer-control system was manufactured by Philips for the Philips 300 series microscopes. It was necessary to modify the specimen stage area of this holder to work in the Philips 400 series microscopes because the distance between the optic axis and holder airlock is different than in the Philips 300 series microscopes. However, the program and interfacing can easily be modified to work with any goniometer type straining holder which uses a penrmanent magnet motor.


2014 ◽  
Vol 20 (2) ◽  
pp. 484-492 ◽  
Author(s):  
B. Layla Mehdi ◽  
Meng Gu ◽  
Lucas R. Parent ◽  
Wu Xu ◽  
Eduard N. Nasybulin ◽  
...  

AbstractThe recent development of in-situ liquid stages for (scanning) transmission electron microscopes now makes it possible for us to study the details of electrochemical processes under operando conditions. As electrochemical processes are complex, care must be taken to calibrate the system before any in-situ/operando observations. In addition, as the electron beam can cause effects that look similar to electrochemical processes at the electrolyte/electrode interface, an understanding of the role of the electron beam in modifying the operando observations must also be understood. In this paper we describe the design, assembly, and operation of an in-situ electrochemical cell, paying particular attention to the method for controlling and quantifying the experimental parameters. The use of this system is then demonstrated for the lithiation/delithiation of silicon nanowires.


2007 ◽  
Vol 15 (6) ◽  
pp. 38-39
Author(s):  
D. J. MacMahon ◽  
E. Raz-Moyal

Semiconductor manufacturers are increasingly turning to Transmission Electron Microscopes (TEMs) to monitor product yield and process control, analyze defects, and investigate interface layer morphology. To prepare TEM specimens, Focused Ion Beam (FIB) technology is an invaluable tool, yielding a standard milled TEM lamella approximately 15 μm wide, 5 μm deep and ~100 nm thick. Several techniques have been developed to extract these tiny objects from a large wafer and view it in the TEM. These techniques, including ex-situ lift-out, H-bar, and in-situ lift-out, have different advantages and disadvantages, but all require painstaking preparation of one specimen at a time.


1996 ◽  
Vol 439 ◽  
Author(s):  
Charles W. Allen ◽  
Edward A. Ryan

AbstractSince Fall 1995, a state-of-the-art intermediate voltage electron microscope (IVEM) has been operational in the HVEM-Tandem Facility with in situ ion irradiation capabilities similar to those of the HVEM of the Facility. A 300 kV Hitachi H-9000NAR is interfaced to the two ion accelerators of the Facility, with a demonstrated point-topoint spatial resolution for imaging of 0.25 nm with the ion beamline attached to the microscope. The IVEM incorporates a Faraday cup system for ion dosimetry with measurement aperture 6.5 cm from the TEM specimen, which was described in Symposium A of the 1995 MRS Fall Meeting. The IVEM is now employed for a variety of in situ ion beam studies ranging from low dose ion damage experiments with GaAs, in which damage zones individual displacement cascades are observed, to implantation studies in metals, in which irradiation-induced noble gas precipitate mobility is studied in real time. In this presentation, the new instrumentation and its specifications will be described briefly, several basic concepts relating to in situ experiments in transmission electron microscopes will be summarized and examples of in situ experiments will be presented which exploit the experimental capabilities of this new user facility instrumentation.


Author(s):  
L. J. Chen ◽  
J. W. Mayer

In-situ dynamical experiments in the transmission electron microscope (TEM) have long interested electron microscopists. In designing and performing the experiments, it is important to minimize the influences of the factors, which include the specimen thickness, electron beam heating, electron irradiation and specimen environments that may affect the validity of in-situ experiments. Comparisons of the results with those of other experiments are also very desirable.In microelectronic device fabrication process, it has become increasingly common to react a few hundred Å in thickness metal films with silicon substrate to form silicide contacts. Ni thin films on silicon have been chosen for in-situ annealing study since this system has been extensively investigated by Rutherford backscattering and glancing angle x-ray experiments. In-situ annealing of Co, Mo, Ti, Pd and W thin films on silicon have also been performed.Ni films, 300 and 400 Å thick, were electron gun deposited on (001) n-type silicon. Thin foils for TEM examination were chemically polished from silicon side. A JEOL 100B microscope equipped with a side entry, single tilt hot stage was used for TEM study.


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