Field Emission Analytical Electron Microscope

1976 ◽  
Vol 34 ◽  
pp. 528-529
Author(s):  
Y. Harada ◽  
Y. Kokubo ◽  
T. Goto ◽  
N. Tamura ◽  
M. Iwatsuki ◽  
...  
Keyword(s):  
Electron Microscope ◽  
Field Emission ◽  
Objective Lens ◽  
General View ◽  
Energy Analyzer ◽  
X Ray ◽  
Transmission Electron ◽  
Analytical Electron ◽  
Analytical Electron Microscope ◽  
Electron Microscopes

Recently, analytical electron microscopes (AEM), which provide the functions of the transmission electron microscope (TEM), scanning electron microscope (SEM) and energy dispersive X-ray spectrometer (EDS) have been put to practical use with a view to analyzing elements in micro areas, xo improve the performance of this type of AEM, a field emission gun was attached to our AEM instead of a conventional thermionic gun. This has allowed a sellected area smaller than several 100 Å to be easily analyzed. Moreover, an electron energy analyzer (EA) was attached to the AEM for detecting light elements which cannot be detected by the EDS.These modifications have resulted in an advanced type of an AEM, namely, a field emission analytical electron microscope (FEAEM).Fig. 1 shows a general view of our FEAEM. The feature of this FEAEM is that it is designed on the basis of a 100 kV field emission electron microscope provided with a strongly-excited objective lens having a very small aberration coefficient and with an eucentric goniometer tiltable to 60°.

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.

X-ray detection performance of a 300KV field-emission Analytical Electron Microscope

1993 ◽  
Vol 51 ◽  
pp. 250-251
Author(s):  
C. E. Lyman ◽  
J. I. Goldstein ◽  
D.B. Williams ◽  
D.W. Ackland ◽  
S. von Harrach ◽  
...  
Keyword(s):  
Electron Microscope ◽  
Field Emission ◽  
Spatial Resolution ◽  
High Spatial Resolution ◽  
Detection Performance ◽  
Electron Gun ◽  
X Rays ◽  
X Ray ◽  
Analytical Electron ◽  
Analytical Electron Microscope

A major goal of analytical electron micrsocopy (AEM) is to detect small amounts of an element in a given matrix at high spatial resolution. While there is a tradeoff between low detection limit and high spatial resolution, a field emission electron gun allows detection of small amounts of an element at sub-lOnm spatial resolution. The minimum mass fraction of one element measured in another is proportional to [(P/B)·P]-1/2 where the peak-to-background ratio P/B and the peak intensity P both must be high to detect the smallest amount of an element. Thus, the x-ray detection performance of an analytical electron microscope may be characterized in terms of standardized measurements of peak-to-background, x-ray intensity, the level of spurious x-rays (hole count), and x-ray detector performance in terms of energy resolution and peak shape.This paper provides measurements of these parameters from Lehigh’s VG Microscopes HB-603 field emission AEM. This AEM was designed to provide the best x-ray detection possible.

The Analysis of Particles With Energy Dispersive X-Ray Spectroscopy (EDS)

1998 ◽  
Vol 4 (S2) ◽  
pp. 184-185
Author(s):  
J. A. Small ◽  
J. A. Armstrong ◽  
D. S. Bright ◽  
B. B. Thorne
Keyword(s):  
Electron Microscope ◽  
Elemental Analysis ◽  
Electron Probe ◽  
Initial Particle ◽  
X Ray ◽  
Transmission Electron ◽  
Analytical Electron ◽  
Analytical Electron Microscope ◽  
The Individual ◽  
Individual Particles

The addition of the Si-Li detector to the electron probe, the scanning electron microscope, and more recently the transmission electron microscope (resulting in the analytical electron microscope) has made it possible to obtain elemental analysis on individual “particles” with dimensions less than 1 nm using EDS. Although some initial particle studies on micrometer-sized particles were done on the electron probe using wavelength dispersive spectrometers, WDS, the variability and complexity of many particle compositions coupled with the high currents necessary for WDS made elemental analysis of particles by WDS difficult at best. In addition, the use of multiple spectrometers, each with a different view of the particle and therefore different particle geometry as shown in Fig. 1, limited the quantitative capabilities of the technique. With the introduction of the Si-Li detector, there was only one spectrometer with a single geometry resulting in the development of various procedures for obtaining quantitative elemental analysis of the individual particles.

Nano-area analysis by an energy-dispersive x-ray spectrometer mounted on a field-emission transmission electron microscope

1991 ◽  
Vol 49 ◽  
pp. 352-353
Author(s):  
T. Hashimoto ◽  
Y. Sato ◽  
Y. Ueki ◽  
T. Kamino ◽  
S. Isakozawa ◽  
...  
Keyword(s):  
Electron Microscope ◽  
Field Emission ◽  
List Type ◽  
Positional Accuracy ◽  
Image Brightness ◽  
X Ray ◽  
Transmission Electron ◽  
Point Analysis ◽  
Analytical Electron ◽  
High Resolution Tem

Hitachi HF-2000 is an analytical electron microscope equipped with a cold field emission electron source which is operable at 200kV. The cold field emission source has an excellent coherency of the beam and an inherent source brightness of about 1,000 times greater than that of the conventional heated sources such as a tungsten hairpin type filament or a LaBs emitter. The HF-2000 is, therefore, advantageous in the following points:1)In the TEM imaging, the illumination beam angle is about 1/10 of conventional microscopes. The information limit can be extended to a higher spacial frequency.2)In a focused fine probe of about 1 nm in diameter, which is typically used for elemental microanalysis, a high probe current of about 100 times greater than that available with conventional TEMs, is available.In addition, it is also possible with the HF-2000 to check the analysis area in high resolution TEM image with sufficient image brightness and contrast during the x-ray work. This capability assures high positional accuracy for point analysis.

Comparison of Performance of an Analytical Electron Microscope at 300 and 100 kV

1984 ◽  
Vol 41 ◽  
Author(s):  
J. Bentley ◽  
E. A. Kenik ◽  
P. Angelini ◽  
A. T. Fisher ◽  
P. S. Sklad ◽  
...  
Keyword(s):  
Electron Microscope ◽  
Materials Science ◽  
Convergent Beam Electron Diffraction ◽  
Beam Electron ◽  
X Ray ◽  
Transmission Electron ◽  
Analytical Electron ◽  
Analytical Electron Microscope ◽  
Convergent Beam ◽  
Electron Energy Loss

AbstractPreliminary results on the performance of an analytical electron microscope (AEM) operating at 300 kV have been obtained and compared with the performance at 100 kV. Some features of the anticipated improvements for transmission electron microscopy (TEM) imaging, convergent beam electron diffraction (CBED), energy dispersive X-ray spectroscopy (EDS), and electron energy loss spectroscopy (EELS) have been studied from the aspect of materials science applications. The electron microscope used was a Philips EM430T operated with a LaB6 cathode and equipped with EDAX 9100/70 EDS and Gatan 607 EELS systems.

An Application of 200kV Ultrahigh Resolution Analytical Electron Microscope

1990 ◽  
Vol 48 (2) ◽  
pp. 98-99
Author(s):  
M. Suzuki ◽  
T. Kaneyama ◽  
E. Watanabe ◽  
M. Naruse ◽  
Y. Kokubo
Keyword(s):  
Electron Microscope ◽  
Spherical Aberration ◽  
Objective Lens ◽  
Theoretical Point ◽  
Ultrahigh Resolution ◽  
X Ray ◽  
Probe Current ◽  
Probe Size ◽  
Analytical Electron ◽  
Analytical Electron Microscope

A 200 kV ultrahigh resolution analytical electron microscope (UHRAEM), JEM-2010, enables both ultrahigh resolution imaging with a theoretical point resolution of 0.194 nm and nm-area analysis. In this paper, its preliminary data for x-ray analysis (Energy Dispersive X ray Spectroscopy: EDS) and its application data will be shown.An objective lens polepiece has been designed to minimize the spherical aberration coefficient (Cs) of the prefield and thereby increase the probe current in small probe size for nm-area EDS analysis. Measured values of Cs and chromatic aberration coefficient (Cc) are 0.5 mm and 1.0 mm, respectively. Fig. 1 shows a theoretical relation between the illumination angle and probe size of this objective lens on the assumption that the brightness of electrons is 6×106 A/cm2 • str in a LaB6 cathode. This calculation shows that an electron probe smaller than 1 nm in diameter is available even with a probe current of 10 pA.

Design of a 400KV Ultrahigh-Resolution Analytical TEM

1990 ◽  
Vol 48 (1) ◽  
pp. 134-135
Author(s):  
H. Tsuno ◽  
T. Honda ◽  
Y. Kokubo
Keyword(s):  
Electron Beam ◽  
Electron Microscope ◽  
Spherical Aberration ◽  
New Technology ◽  
Objective Lens ◽  
Ultrahigh Resolution ◽  
X Ray ◽  
Analytical Tem ◽  
Analytical Electron ◽  
Analytical Electron Microscope

The condenser-objective (C/O) lens proposed by Riecke, which has a very short gap length and small spherical aberration, was utilized for a commercial 200 kV ultrahigh resolution analytical TEM by Yanaka and Kaneyama. Fig. 1 shows the relation between theoretical resolution and objective lens (OL) spherical aberration coefficient (Cs) at accelerating voltages 200-1250 kV. It was reported that the Cs of a 400kV high resolution TEM is 1.0 mm and its resolution is 0.167 nm. The Cs of 400kV analytical TEM is 1.8 mm and the pre-field spherical aberration coefficient (Csp) is 1.8 mm. Fig. 2 (A), (B) show beam broading in specimens against the thickness when a 200kV and a 400kV electron beam transmit the specimen (C-Au), respectively. The broading of 400kV electron beam is about half of 200kV one. Then it is expected that spacial resolution of x-ray analysis improve. The above-captioned 400kV ultrahigh resolution analytical TEM is designed by applying a new technology which is adopted for a 200kV ultrahigh resolution analytical electron microscope, JEM-2010.Its fundamental construction is the same as the 400kV analytical electron microscope JEM-4000FX, except the 0L. The goniometer is a modified JEM-2010 goniometer, because it is too small for 400kV EM. Although it was expected that the focus ampere turn increases because of its short gap length, the objective lens coil used by JEM-4000EX/FX is adopted, because it has enough capacity. The shapes of the upper yoke and objective polepiece were calculated by the finite element method (55×110 Meshes) under the following condition: (1) maximum tilting-angle 10° (2) x-ray take-off angle 17.5° and solid angle 0.068 strad (3) minimized Cs.

An Investigation of the Pyroantimonate Reaction for Sodium Localisation Using the Analytical Electron Microscope, EMMA-4

1971 ◽  
Vol 29 ◽  
pp. 406-407
Author(s):  
L. Herman ◽  
T. Sato ◽  
B. A. Weavers
Keyword(s):  
Electron Microscope ◽  
X Rays ◽  
X Ray ◽  
Transmission Electron ◽  
Analytical Electron ◽  
Analytical Electron Microscope ◽  
Viewing Screen ◽  
Conventional Transmission Electron Microscope ◽  
The Continuum

The analytical electron microscope, EMMA-4, is designed specifically to perform x-ray microanalysis of conventional transmission electron microscope specimens.The analysis facilities consist of two fully focussing crystal spectrometers each of which can be tuned to collect x-rays emitted from elements of atomic number greater than 11. In addition to the two crystal spectrometers there is a non-dispersive detector which can be used to monitor the total x-ray emission of the specimen and adds the facility for determination of the “continuum” radiation for quantitative analysis. The exact area of analysis is always located by direct observation of the viewing screen.

A Field Emission System For Transmission Electron Microscopy

1973 ◽  
Vol 31 ◽  
pp. 298-299
Author(s):  
Michel Troyonal ◽  
Huei Pei Kuoal ◽  
Benjamin M. Siegelal
Keyword(s):  
Electron Microscope ◽  
Field Emission ◽  
Optical System ◽  
High Vacuum ◽  
Ultra High Vacuum ◽  
Objective Lens ◽  
Electron Optical System ◽  
Cross Sectional ◽  
Transmission Electron ◽  
Emission System

A field emission system for our experimental ultra high vacuum electron microscope has been designed, constructed and tested. The electron optical system is based on the prototype whose performance has already been reported. A cross-sectional schematic illustrating the field emission source, preaccelerator lens and accelerator is given in Fig. 1. This field emission system is designed to be used with an electron microscope operated at 100-150kV in the conventional transmission mode. The electron optical system used to control the imaging of the field emission beam on the specimen consists of a weak condenser lens and the pre-field of a strong objective lens. The pre-accelerator lens is an einzel lens and is operated together with the accelerator in the constant angular magnification mode (CAM).

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