A survey of new electron-optical materials characterisation techniques

1990 ◽  
Vol 48 (4) ◽  
pp. 390-391
Author(s):  
J.C.H. Spence
Keyword(s):  
Electron Microscope ◽  
Solid State ◽  
Spatial Resolution ◽  
Optical Materials ◽  
Materials Science ◽  
Planar Defects ◽  
Data Aquisition ◽  
Electron Microscopes ◽  
Characterisation Techniques ◽  
Solid State System

It is rare that the detection of a new signal from a solid-state system does not in time prove useful for materials characterisation. At the same time, the increasing number of detectors fitted to modem electron microscopes, their improved probe-forming capabilities and vacuum performance and the trend toward full digital control and data aquisition, together with the use of more self-explanatory human interfaces in software has greatly increased the number of useful signals and their combinations, making the modem electron microscope an extraordinarily powerful and versatile instrument for materials characterisation. We list below some of the more promising new ways in which the signals available from modem TEM/STEM and SEM instruments may be used in materials science.1. Backscattered channelling imaging. By detecting elastically back-scattered electrons using an energy filter, striking diffraction contrast images of line and planar defects may be obtained from bulk samples. A field-emission SEM instrument is required for this work, operating at about 50 kV.The spatial resolution achieved is about 10 nm, the images come from a depth of less than about 100 nm, and atomically clean surfaces are not required.

Remote On-Line Control of a High-Voltage in situ Transmission Electron Microscope with A Rational User Interface

1996 ◽  
Vol 54 ◽  
pp. 384-385
Author(s):  
M.A. O’Keefe ◽  
J. Taylor ◽  
D. Owen ◽  
B. Crowley ◽  
K.H. Westmacott ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Electron Microscope ◽  
User Interface ◽  
Transmission Electron Microscope ◽  
High Voltage ◽  
Materials Science ◽  
Transmission Electron ◽  
On Line ◽  
Electron Microscopes

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.

Analysis of Interesting Materials in the Environmental SEM: You Put What in Your Microscope?

2001 ◽  
Vol 7 (S2) ◽  
pp. 776-777
Author(s):  
John F. Mansfield
Keyword(s):  
Electron Microscope ◽  
Chemical Engineering ◽  
Materials Science ◽  
Variable Pressure ◽  
Environmental Scanning ◽  
Specimen Preparation ◽  
Wide Range ◽  
Electron Microscopes ◽  
Scanning Electron Microscopes ◽  
Scanning Electron

The environmental scanning electron microscope (ESEM™) and variable pressure electron microscope (VPSEM) have become accepted tools in the contemporary electron microscopy facility. Their flexibility and their ability to image almost any sample with little, and often no, specimen preparation has proved so attractive that each manufacturer of scanning electron microscopes now markets a low vacuum model.The University of Michigan Electron Microbeam Analysis Laboratory (EMAL) operates two variable pressure instruments, an ElectroScan E3 ESEM and a Hitachi S3200N VPSEM. The E3 ESEM was acquired in the early 1990s with funding from the Amoco Foundation and it has been used to examine an extremely wide variety of different materials. Since EMAL serves the entire university community, and offers support to neighboring institutions and local industry, the types of materials examined span a wide range. There are users from Materials Science & Engineering, Chemical Engineering, Nuclear Engineering, Electrical Engineering, Physics, Chemistry, Geology, Biology, Biophysics, Pharmacy and Pharmacology.

A superior cathodoluminescence spectral analysis and imaging system for semiconductor characterisation

1991 ◽  
Vol 49 ◽  
pp. 838-839
Author(s):  
P J Wright
Keyword(s):  
Spectral Analysis ◽  
Electron Microscope ◽  
Spatial Resolution ◽  
High Spatial Resolution ◽  
Imaging System ◽  
Fibre Optic ◽  
Transmission Losses ◽  
The Past ◽  
Improved Performance ◽  
Electron Microscopes

Cathodoluminescence is a useful technique in the structural and electro optical characterisation of semiconductors. When performed in a electron microscope, both high spatial resolution images and spectra may be obtained by use of the correct equipment.Many designs for instruments suitable for cathodoluminescence spectral analysis and imaging in electron microscopes have been described in the literature during the past 25 years. These have often exhibited improved performance when compared with commercially available systems. The prime reason for this has been the willingness of the dedicated CL researcher to mount large, heavy monochromators directly to the chamber of their microscope. The result has been a microscope committed to CL analysis. However, many potential CL users have to use shared facilities and may not compromise the performance or appearance of the microscope. Subsequently, many CL systems have had the monochromator decoupled from the CL collection optics by either fibre optic bundles or quartz fibres. This has allowed the monochromator and its associated detectors to be easily decoupled from the SEM when not in use. Considerable transmission losses have been incurred and in many cases, it has been necessary to duplicate detectors to allow both spectral analysis and imaging. This has resulted in instruments which were less than optimum in both efficiency and operation.

SHaRE: Collaborative materials science research

1988 ◽  
Vol 46 ◽  
pp. 804-805
Author(s):  
Edward A. Kenik ◽  
Karren L. More
Keyword(s):  
Electron Microscope ◽  
Materials Science ◽  
Analytical Electron Microscopy ◽  
Science Research ◽  
Atom Probe ◽  
Probe Field ◽  
Transmission Electron ◽  
Wide Range ◽  
Analytical Electron ◽  
Electron Microscopes

The Shared Research Equipment (SHaRE) Program provides access to the wide range of advanced equipment and techniques available in the Metals and Ceramics Division of ORNL to researchers from universities, industry, and other national laboratories. All SHaRE projects are collaborative in nature and address materials science problems in areas of mutual interest to the internal and external collaborators. While all facilities in the Metals and Ceramics Division are available under SHaRE, there is a strong emphasis on analytical electron microscopy (AEM), based on state-of-the-art facilities, techniques, and recognized expertise in the Division. The microscopy facilities include four analytical electron microscopes (one 300 kV, one 200 kV, and two 120 kV instruments), a conventional transmission electron microscope with a low field polepiece for examination of ferromagnetic materials, a high voltage (1 MV) electron microscope with a number of in situ capabilities, and a variety of EM support facilities. An atom probe field-ion microscope provides microstructural and elemental characterization at atomic resolution.

Instrumentation and Computation

1990 ◽  
Vol 48 (1) ◽  
pp. 2-3
Author(s):  
P.B. Hirsch
Keyword(s):  
Electron Microscopy ◽  
Electron Microscope ◽  
Materials Science ◽  
Image Interpretation ◽  
Specimen Preparation ◽  
Scanning Tunnelling Microscope ◽  
Transmission Electron ◽  
Wide Range ◽  
Electron Microscopes ◽  
Types Of Information

The benefit to society arising from developments in instrumentation and computation can be judged primarily by the advances in knowledge and understanding generated by their application in different branches of science, covered in the other papers in this symposium. Without advances in instrumentation none of these advances is possible; developments in instrumentation and in image interpretation are therefore fundamental to and precede scientific advances in fields in which knowledge of structure is important. There is little doubt that the revolutionary first step was the development of the transmission electron microscope (TEM) in 1931 by Ernst Ruska; a second was the development of the scanning electron microscope (SEM); and the third the introduction of the scanning tunnelling microscope (STM) for high resolution surface imaging, by Binnig and Rohrer.The TEM and SEM have undergone continuous developments over the last 50 years or so, and have had a far-reaching impact in a wide range of disciplines; the STM is a relative newcomer but no doubt it too will have an increasing impact in furthering our understanding of solids and surfaces in particular. Once the basic instruments became available subsequent developments have been driven by the demands of the scientific disciplines in which these instruments have been applied. Many of the new developments in instrumentation and interpretation have been pioneered by the users themselves, and these in turn have led to modifications in commercial instruments to make such advances in technique available to the user community as a whole. Other developments have been initiated directly by the manufacturers as a result of a perceived need. There has been and continues to be a close interaction between the developers of hardware (not only of electron microscopes but also of ancillary equipment, e.g. microanalysis attachments, image processing equipment, specialist specimen stages, and specimen preparation facilities) and the users, leading to extensions in the range of applications and the types of information which can be obtained by electron microscopy. The following examples from the developments of electron microscopy in Materials Science illustrate these interactions and the particular advances arising from specific developments:

Up Close: Center for Electron Microscopy of Materials Science at the University of Antwerp

MRS Bulletin ◽  
1994 ◽  
Vol 19 (9) ◽  
pp. 57-60
Author(s):  
G. Van Tendeloo ◽  
D. Schryvers ◽  
D. Van Dyck ◽  
J. Van Landuyt ◽  
S. Amelinckx
Keyword(s):  
Electron Microscopy ◽  
Electron Microscope ◽  
Materials Science ◽  
Imaging System ◽  
Academic Staff ◽  
Video Camera ◽  
Local Composition ◽  
Electron Microscopes ◽  
The University ◽  
Single Technique

The Center for Electron Microscopy of Materials Science (EMAT) at the University of Antwerp, Belgium, started in 1967 under the initiative of S. Amelinckx. While most materials science laboratories choose a particular research theme (e.g., superconducting materials) and study it through several available techniques, the EMAT group at Antwerp has taken a different approach. From the beginning, EMAT has concentrated on a single technique: transmission electron microscopy. Since the laboratory, as well as the university, is very small, we felt it would be better to be excellent in a single technique than to have limited proficiency in several techniques. Until recently, EMAT has been able to maintain this strategy, although the group has grown considerably; at present it consists of four academic staff members, four postdocs, and 12 PhD students, supported by a technical and administrative staff of eight people.Instrumentation at EMATThe range of electron microscopes and related instruments in the EMAT laboratory is quite extensive and includes several instruments dedicated to specific techniques. The instruments include:∎ A 1,250 kV high-voltage electron microscope, used mainly for studying processed semiconductor devices and for in situ radiation experiments.∎ A 400 kV and a 200 kV high-resolution electron microscope with resolving powers of 1.7 Å and 2.5 Å, respectively. Both instruments are equipped with a TV imaging system and a video camera.∎ A 200 kV and a 100 kV analytical electron microscope with large tilting possibilities, cooling and heating facilities, and capability for energy dispersive x-ray analysis for measuring the local composition.

scholarly journals Sub-Ångstrom Low-Voltage Performance of a Monochromated, Aberration-Corrected Transmission Electron Microscope

2010 ◽  
Vol 16 (4) ◽  
pp. 386-392 ◽  
Author(s):  
David C. Bell ◽  
Christopher J. Russo ◽  
Gerd Benner
Keyword(s):  
Electron Microscope ◽  
Electron Energy ◽  
Transmission Electron Microscope ◽  
Cross Sections ◽  
Materials Science ◽  
Low Voltage ◽  
Transmission Electron ◽  
Electron Microscopes ◽  
Voltage Performance ◽  
Aberration Corrected

AbstractLowering the electron energy in the transmission electron microscope allows for a significant improvement in contrast of light elements and reduces knock-on damage for most materials. If low-voltage electron microscopes are defined as those with accelerating voltages below 100 kV, the introduction of aberration correctors and monochromators to the electron microscope column enables Ångstrom-level resolution, which was previously reserved for higher voltage instruments. Decreasing electron energy has three important advantages: (1) knock-on damage is lower, which is critically important for sensitive materials such as graphene and carbon nanotubes; (2) cross sections for electron-energy-loss spectroscopy increase, improving signal-to-noise for chemical analysis; (3) elastic scattering cross sections increase, improving contrast in high-resolution, zero-loss images. The results presented indicate that decreasing the acceleration voltage from 200 kV to 80 kV in a monochromated, aberration-corrected microscope enhances the contrast while retaining sub-Ångstrom resolution. These improvements in low-voltage performance are expected to produce many new results and enable a wealth of new experiments in materials science.

Materials Science in the Electron Microscope

MRS Bulletin ◽  
1994 ◽  
Vol 19 (6) ◽  
pp. 17-21 ◽  
Author(s):  
Frances M. Ross
Keyword(s):  
Electron Microscopy ◽  
Electron Microscope ◽  
Real Time ◽  
Materials Science ◽  
Foil Thickness ◽  
Specimen Holder ◽  
Transmission Electron ◽  
Dynamic Experiments ◽  
Electron Microscopes

This issue of the MRS Bulletin aims to highlight the innovative and exciting materials science research now being done using in situ electron microscopy. Techniques which combine real-time image acquisition with high spatial resolution have contributed to our understanding of a remarkably diverse range of physical phenomena. The articles in this issue present recent advances in materials science which have been made using the techniques of transmission electron microscopy (TEM), including holography, scanning electron microscopy (SEM), low-energy electron microscopy (LEEM), and high-voltage electron microscopy (HVEM).The idea of carrying out dynamic experiments involving real-time observation of microscopic phenomena has always had an attraction for materials scientists. Ever since the first static images were obtained in the electron microscope, materials scientists have been interested in observing processes in real time: we feel that we obtain a true understanding of a microscopic phenomenon if we can actually watch it taking place. The idea behind “materials science in the electron microscope” is therefore to use the electron microscope—with its unique ability to image subtle changes in a material at or near the atomic level—as a laboratory in which a remarkable variety of experiments can be carried out. In this issue you will read about dynamic experiments in areas such as phase transformations, thin-film growth, and electromigration, which make use of innovative designs for the specimen, the specimen holder, or the microscope itself. These articles speak for themselves in demonstrating the power of real-time analysis in the quantitative exploration of reaction mechanisms.The first transmission electron microscopes operated at low accelerating voltages, up to about 100 kV. This placed a severe limitation on the thickness of foils that could be examined: Heavy elements, for example, had to be made into foils thinner than 0.1 μm. It was felt that any phenomenon whose “mean free path” was comparable to the foil thickness would be significantly affected by the foil surfaces, and therefore would be unsuitable for study in situ. However, technology quickly generated ever higher accelerating voltages, culminating in the giant 3 MeV electron microscopes. At these voltages, electrons can penetrate materials as thick as 6–9 μm for light elements such as Si and Al, and 1 μm for very heavy ones such as Au and U.

scholarly journals Materials science applications of a 120kV FEG TEM/STEM: Triskaidekaphilia

1991 ◽  
Vol 49 ◽  
pp. 698-699
Author(s):  
J. Bentley ◽  
A. T. Fisher ◽  
E. A. Kenik ◽  
Z. L. Wang
Keyword(s):  
Electron Microscope ◽  
Materials Science ◽  
X Ray ◽  
Transmission Electron ◽  
Analytical Electron ◽  
Analytical Electron Microscope ◽  
Scanning Transmission ◽  
Potential Impact ◽  
Electron Microscopes ◽  
Electron Energy Loss

The introduction by several manufacturers of 200kV transmission electron microscopes (TEM) equipped with field emission guns affords the opportunity to assess their potential impact on materials science by examining applications of similar 100-120kV instruments that have been in use for more than a decade. This summary is based on results from a Philips EM400T/FEG configured as an analytical electron microscope (AEM) with a 6585 scanning transmission (STEM) unit, ED AX 9100/70 or 9900 energy dispersive X-ray spectroscopy (EDS) systems, and Gatan 607 serial- or 666 parallel-detection electron energy-loss spectrometers (EELS). Examples in four areas that illustrate applications that are impossible or so difficult as to be impracticable with conventional thermionic electron guns are described below.

Semiconductor X-Ray Detection in the Electron Microscope

1969 ◽  
Vol 27 ◽  
pp. 130-131
Author(s):  
R. H. Duff ◽  
S. L. Bender
Keyword(s):  
Electron Microscope ◽  
Solid State ◽  
High Resolution ◽  
Gas Flow ◽  
X Ray ◽  
Solid State Detectors ◽  
Transmission Electron ◽  
Electron Microscopes ◽  
Scanning Electron Microscopes ◽  
Conventional Transmission Electron Microscope

With the introduction of solid state detectors having resolutions of 300 eV or better, the feasibility of an efficient, nongeometry dependent X-ray detector of high resolution became a reality. The use of X-ray detecting systems in conjunction with electron microscopes has been limited to the dispersive type which is highly dependent on geometry or to the gas flow proportional counter which has poor resolution. Recently, high resolution solid state detectors have been used with scanning electron microscopes; however, no use has been made of them in the conventional transmission electron microscope. The usefulness of an elemental analysis together with morphological and crystallographic information is obvious.

Sign in / Sign up

Export Citation Format

Share Document