Information and Dose in the Scanning Transmission Ion Microscope

1980 ◽  
Vol 38 ◽  
pp. 232-233
Author(s):  
Fox T. R. ◽  
R. Levi-Setti
Keyword(s):  
Information Retrieval ◽  
Electron Microscope ◽  
Elastic Scattering ◽  
Energy Loss ◽  
Cross Sections ◽  
Previous Analysis ◽  
Single Scattering ◽  
Screening Length ◽  
Relative Damage ◽  
Scanning Transmission

At an earlier meeting [1], we discussed information retrieval in the scanning transmission ion microscope (STIM) compared with the electron microscope at the same energy. We treated elastic scattering contrast, using total elastic cross sections; relative damage was estimated from energy loss data. This treatment is valid for “thin” specimens, where the incident particles suffer only single scattering. Since proton cross sections exceed electron cross sections, a given specimen (e.g., 1 μg/cm2 of carbon at 25 keV) may be thin for electrons but “thick” for protons. Therefore, we now extend our previous analysis to include multiple scattering. Our proton results are based on the calculations of Sigmund and Winterbon [2], for 25 keV protons on carbon, using a Thomas-Fermi screened potential with a screening length of 0.0226 nm. The electron results are from Crewe and Groves [3] at 30 keV.

Development of Line Analysis and Real-Time Elemental Mapping System in Stem Equipped with a Two-Window Energy Filter

2001 ◽  
Vol 7 (S2) ◽  
pp. 1134-1135
Author(s):  
K. Kaji ◽  
T. Aoyama ◽  
S. Taya ◽  
S. Isakozawa
Keyword(s):  
Electron Microscope ◽  
Energy Loss ◽  
Transmission Electron Microscope ◽  
Scanning Transmission Electron Microscope ◽  
Elemental Mapping ◽  
Additional Function ◽  
Edge Structure ◽  
Transmission Electron ◽  
Mapping System ◽  
Scanning Transmission

The ability to obtain elemental maps processed by using inelastically scattered electrons in a transmission electron microscope (TEM) or a scanning transmission electron microscope (STEM) is extremely useful in the analysis of materials, and semiconductor devices such as ULSI’s and GMR heads. Electron energy loss spectra (EELS) also give useful information not only to identify unknown materials but also to study chemical bonding states of the objective atoms. Hitachi developed an elemental mapping system, consisting of a STEM (Hitachi, HD- 2000) equipped with a two-window energy filter (Hitachi, ELV-2000), and performed realtime conventional jump-ratio images with nanometer resolution by in-situ calculation of energy-filtered signals [1]. Additional function of acquiring EELS along any lines on specimen has been developed in this system to investigate the energy loss near edge structure (ELNES).Figure 1 shows a schematic figure of the two-window energy filter, consisting of two quadrupole lenses for focusing and zooming spectra, respectively, a magnetic prism spectrometer, a deflection coil and two kinds of electron beam detectors.

Optimization of Acquisition Parameters for Atomic-Column Electron Energy-Loss Spectrum Imaging in a JEM-2200FS Aberration-Corrected Scanning Transmission Electron Microscope

2008 ◽  
Vol 14 (S2) ◽  
pp. 1400-1401 ◽  
Author(s):  
M Watanabe ◽  
M Kanno ◽  
D Ackland ◽  
CJ Kiely ◽  
DB Williams
Keyword(s):  
Electron Microscope ◽  
New Mexico ◽  
Energy Loss ◽  
Scanning Transmission Electron Microscope ◽  
Atomic Column ◽  
Transmission Electron ◽  
Scanning Transmission ◽  
Spectrum Imaging ◽  
Electron Energy Loss ◽  
Aberration Corrected

Extended abstract of a paper presented at Microscopy and Microanalysis 2008 in Albuquerque, New Mexico, USA, August 3 – August 7, 2008

Energy Loss Imaging in Biology

1982 ◽  
Vol 40 ◽  
pp. 416-419
Author(s):  
H. Shuman ◽  
A.V. Somlyo ◽  
A.P. Somlyo ◽  
T. Frey ◽  
D. Safer
Keyword(s):  
Electron Microscope ◽  
Energy Loss ◽  
Cross Section ◽  
Cross Sections ◽  
Count Rate ◽  
Electron Flux ◽  
Characteristic Energy ◽  
Spectrometer Slit ◽  
Electron Energy Loss ◽  
Sensitive Method

It has been recognized for sometime that electron energy loss spectroscopy (EELS) is potentially the most sensitive method of measuring elemental composition in the electron microscope. Magnetic sector spectrometers currently in use collect most of the inelastically scattered electrons, while the cross sections for ionization of the L2 3 levels of the biologically important elements are large. The energies of the theoretically predicted L2 3 absorption edge maxima and their corresponding differential cross section for lOmrad collection and 80keV incident electrons are shown in Table I. The characteristic energy loss electron count rate expected from one atom with lOeV spectrometer slit width and lOOA/cm2 (the maximum available from a tungsten hairpin) electron flux at the specimen, indicates that the minimum detectable mass sensitivity of EELS will be high. An experimentally determined count rate and cross section for the Fe M2, 3 edge was determined from the ferritin images shown in Fig. 1.

ELECTRON ENERGY LOSS SPECTROSCOPY AND ANNULAR DARK FIELD IMAGING AT A NANOMETER RESOLUTION IN A SCANNING TRANSMISSION ELECTRON MICROSCOPE

2000 ◽  
Vol 07 (04) ◽  
pp. 475-494 ◽  
Author(s):  
O. STÉPHAN ◽  
A. GLOTER ◽  
D. IMHOFF ◽  
M. KOCIAK ◽  
C. MORY ◽  
...  
Keyword(s):  
Electron Microscope ◽  
Energy Loss ◽  
Electron Energy ◽  
Transmission Electron Microscope ◽  
Electron Energy Loss Spectroscopy ◽  
Scanning Transmission Electron Microscope ◽  
Scanning Transmission Electron ◽  
Transmission Electron ◽  
Scanning Transmission ◽  
Electron Energy Loss

The basics of electron energy loss spectroscopy (EELS) performed in the context of a scanning transmission electron microscope are described. This includes instrumentation, information contained in an EELS spectrum, data acquisition and processing, and some illustrations by a few examples.

Sign in / Sign up

Export Citation Format

Share Document