Development of a 1MV-Field-Emission Electron Microscope I. Instrument

2000 ◽  
Vol 6 (S2) ◽  
pp. 1138-1139
Author(s):  
I. Matsui ◽  
T. Katsuta ◽  
T. Kawasaki ◽  
S. Hayashi ◽  
T. Furutsu ◽  
...  
Keyword(s):  
Electron Microscope ◽  
Field Emission ◽  
Transmission Electron Microscope ◽  
Scanning Transmission Electron Microscope ◽  
Electron Holography ◽  
Lorentz Microscopy ◽  
Transmission Electron ◽  
Scanning Transmission ◽  
Resolution Imaging ◽  
Electron Microscopes

We have developed 100-kV, 200-kV, and 350-kV cold-field-emission transmission electron microscopes (FE-TEMs) successively up to this time. Using these instruments, we have been studying the magnetic structure of materials, high-resolution imaging by electron holography, and dynamic observation of the vortex in superconductors by Lorentz microscopy. To make more progress in our research, we need a better electron beam in terms of coherency, beam brightness, and penetration. Here, we report a new lMV-cold-field-emission transmission electron microscope we have developed. Historically, the pioneering projects on a lMV-field-emission scanning transmission electron microscope (FE-STEM) (Zeitler and Crewe, 1974) and a 1.6MV FE-STEM (Jouffrey et al., 1984) have been reported. In 1988, Maruse and Shimoyama obtained a lMV-field-emission beam using their 1.25MV-STEM connected to a field-emission gun. Since then, continuous improvements in beam brightness has been made.The target specifications of our 1 MV-cold-field-emission TEM (H-1000FT) are as follows: Acceleration voltage: 1MV, high-voltage stability :

A Prototype Field-Emission Scanning Transmission Electron Microscope

1973 ◽  
Vol 31 ◽  
pp. 296-297
Author(s):  
J.R. Banbury ◽  
U. R. Bance
Keyword(s):  
Electron Microscope ◽  
Field Emission ◽  
Transmission Electron Microscope ◽  
Scanning Transmission Electron Microscope ◽  
Scanning Transmission Electron ◽  
Transmission Electron ◽  
Wide Range ◽  
Scanning Transmission ◽  
Further Development ◽  
Diode Voltage

A prototype field emission scanning transmission electron microscope has been constructed and is under further development at AEI Scientific Apparatus Limited.The field emission gun has a triode construction, with geometry such as to produce a divergent beam from a virtual source whose position remains substantially constant over a wide range of total accelerating voltages. The gun has been operated satisfactorily from below 10 kV to over 90 kV (upper limit set by power supplies), with the field emission diode voltage typically between 2 kV and 4 kV and total emission of a few microamps. Single-crystal tungsten tips of either (111) or (310) orientation are used, though (310) tips normally produce a superior probe current stability.

Tuning Fifth-Order Aberrations in a Quadrupole-Octupole Corrector

2012 ◽  
Vol 18 (4) ◽  
pp. 699-704 ◽  
Author(s):  
Andrew R. Lupini ◽  
Stephen J. Pennycook
Keyword(s):  
Electron Microscope ◽  
Transmission Electron Microscope ◽  
Spherical Aberration ◽  
Scanning Transmission Electron Microscope ◽  
Low Energy ◽  
Third Order ◽  
Transmission Electron ◽  
Scanning Transmission ◽  
Electron Microscopes ◽  
Fifth Order

AbstractThe resolution of conventional electron microscopes is usually limited by spherical aberration. Microscopes equipped with aberration correctors are then primarily limited by higher order, chromatic, and misalignment aberrations. In particular the Nion third-order aberration correctors installed on machines with a low energy spread and possessing sophisticated alignment software were limited by the uncorrected fifth-order aberrations. Here we show how the Nion fifth-order aberration corrector can be used to adjust and reduce some of the fourth- and fifth-order aberrations in a probe-corrected scanning transmission electron microscope.

Attainment of 40.5 pm spatial resolution using 300 kV scanning transmission electron microscope equipped with fifth-order aberration corrector

Microscopy ◽  
2017 ◽  
Vol 67 (1) ◽  
pp. 46-50
Author(s):  
Shigeyuki Morishita ◽  
Ryo Ishikawa ◽  
Yuji Kohno ◽  
Hidetaka Sawada ◽  
Naoya Shibata ◽  
...  
Keyword(s):  
Electron Microscope ◽  
Spatial Resolution ◽  
Transmission Electron Microscope ◽  
Scanning Transmission Electron Microscope ◽  
Scanning Transmission Electron ◽  
Transmission Electron ◽  
Scanning Transmission ◽  
Technological Developments ◽  
Resolution Imaging ◽  
Fifth Order

Abstract The achievement of a fine electron probe for high-resolution imaging in scanning transmission electron microscopy requires technological developments, especially in electron optics. For this purpose, we developed a microscope with a fifth-order aberration corrector that operates at 300 kV. The contrast flat region in an experimental Ronchigram, which indicates the aberration-free angle, was expanded to 70 mrad. By using a probe with convergence angle of 40 mrad in the scanning transmission electron microscope at 300 kV, we attained the spatial resolution of 40.5 pm, which is the projected interatomic distance between Ga–Ga atomic columns of GaN observed along [212] direction.

Direct observations of semithin sections by the use of TEM and STEM

1978 ◽  
Vol 36 (2) ◽  
pp. 104-105
Author(s):  
Toshio Sakai
Keyword(s):  
Electron Microscope ◽  
Epoxy Resin ◽  
Transmission Electron Microscope ◽  
Scanning Transmission Electron Microscope ◽  
Direct Observations ◽  
Transmission Electron ◽  
Semithin Sections ◽  
Scanning Transmission ◽  
Electron Microscopes ◽  
Rats And Mice

It has been routin to cut semithin sections to look for desired areas before cutting ultrathin sections for electron microscope studies. A new method made it possible to observe larger semithin sections of epoxy resin-embedded tissue with both light microscope and two kinds of electron microscopes,: Transmission Electron Microscope and Scanning Transmission Electron Microscope.Samples obtained from kidneys of rats and mice were sliced to 0. 5.mm to 1 mm thickness. They were fixed for 4 hours in Sorensen phosphate buffer of pH 7.4, containing 2 % glutaraldehyde and 1.5 % paraformaldehyde, rinsed in plain buffer for 12 hours (overnight) and postfixed in 1 % osmium tetroxide buffered with phosphate for 90 minutes. The tissu blocks were then embedded in epoxy resin in a ratio of 6:4 or 5:5 by weight, based on the method of Luft.

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