Electron radiation damage of natural zeolites at room and low temperature

Zeolites are easily changed to amorphous under electron beam irradiation. Bando reported that this phenomena take place at low temperature with 1/20 dose of room temperature. In the present work this phenomena was investigated using two kinds of specimens, by changing temperature, electron energy (100 kV-350 kV) and also by applying an electron energy loss spectrometer.Mesolite is from Yaizu, Sizuoka Prefecture and Thomsonite is from Nishijima, Yamanasi Pref. , Japan. The specimen were ground to fine powder and dispersed on a microgrid. A Faraday gage which was installed in the observing chamber of the microscope was used for measure the dose rate. Decomposition was determined by measuring the current of a diffracted spot by the Faraday gage. Observation at low temperature was carried out using low temperature specimen holders fabricated to 200 kV and 400 kV electron microscopes.Fig. 1 (a), (b) are high resolution lattice images of Mesolite by 200 kV TEM operated in room temperature, (b) was taken 20 second after the same part of (a). The thickness of amorphous region in (a) is 8 nm, in (b) the amorphous region increased to 30 nm.

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Low temperature electron energy loss spectra of acetylene chemisorbed on metal single-crystal surfaces; Cu(111), Ni(110) and Pd(110)

Surface Science ◽

10.1016/0039-6028(84)90010-4 ◽

1984 ◽

Vol 139 (1) ◽

pp. 87-97 ◽

Cited By ~ 71

Author(s):

B.J Bandy ◽

M.A Chesters ◽

M.E Pemble ◽

G.S McDougall ◽

N Sheppard

Keyword(s):

Low Temperature ◽

Energy Loss ◽

Single Crystal ◽

Electron Energy ◽

Crystal Surfaces ◽

Single Crystal Surfaces ◽

Metal Single Crystal ◽

Temperature Electron ◽

Electron Energy Loss ◽

Electron Energy Loss Spectra

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Low temperature electron energy loss spectra of acetylene chemisorbed on metal single-crystal surfaces; Cu(111), Ni(110) and Pd(110)

Surface Science Letters ◽

10.1016/0167-2584(84)90434-1 ◽

1984 ◽

Vol 139 (1) ◽

pp. A121-A122

Author(s):

B.J. Bandy ◽

M.A. Chesters ◽

M.E. Pemble ◽

G.S. McDougall ◽

N. Sheppard

Keyword(s):

Low Temperature ◽

Energy Loss ◽

Single Crystal ◽

Electron Energy ◽

Crystal Surfaces ◽

Single Crystal Surfaces ◽

Metal Single Crystal ◽

Temperature Electron ◽

Electron Energy Loss ◽

Electron Energy Loss Spectra

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Trends in Electron Energy Loss Spectroscopy

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100078675 ◽

1977 ◽

Vol 35 ◽

pp. 228-229

Author(s):

C. Colliex ◽

P. Trebbia

Keyword(s):

Energy Loss ◽

Electron Energy ◽

Electron Energy Loss Spectroscopy ◽

Materials Science ◽

Analytical Technique ◽

Recent Developments ◽

Quantitative Results ◽

Electron Microscopes ◽

Electron Energy Loss ◽

Primary Electrons

The physical foundations for the use of electron energy loss spectroscopy towards analytical purposes, seem now rather well established and have been extensively discussed through recent publications. In this brief review we intend only to mention most recent developments in this field, which became available to our knowledge. We derive also some lines of discussion to define more clearly the limits of this analytical technique in materials science problems.The spectral information carried in both low ( 0<ΔE<100eV ) and high ( >100eV ) energy regions of the loss spectrum, is capable to provide quantitative results. Spectrometers have therefore been designed to work with all kinds of electron microscopes and to cover large energy ranges for the detection of inelastically scattered electrons (for instance the L-edge of molybdenum at 2500eV has been measured by van Zuylen with primary electrons of 80 kV). It is rather easy to fix a post-specimen magnetic optics on a STEM, but Crewe has recently underlined that great care should be devoted to optimize the collecting power and the energy resolution of the whole system.

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In Situ Analysis of Surface Contaminant Desorption during Low-Temperature Silicon Substrate Cleaning using Reflection Electron Energy Loss Spectrometry

MRS Proceedings ◽

10.1557/proc-259-449 ◽

1992 ◽

Vol 259 ◽

Cited By ~ 1

Author(s):

Selmer S. Wong ◽

Shouleh Nikzad ◽

Channing C. Ahn ◽

Aimee L. Smith ◽

Harry A. Atwater

Keyword(s):

Low Temperature ◽

Energy Loss ◽

Electron Energy ◽

Core Loss ◽

Temperature Dependent ◽

Electron Energy Loss Spectrometry ◽

Analysis Technique ◽

Chemical Analysis Technique ◽

Electron Energy Loss

ABSTRACTWe have employed reflection electron energy loss spectrometry (REELS), a surface chemical analysis technique, in order to analyze contaminant coverages at the submonolayer level during low-temperature in situ cleaning of hydrogen-terminated Si(100). The chemical composition of the surface was analyzed by measurements of the C K, O K and Si L2,3 core loss intensities at various stages of the cleaning. These results were quantified using SiC(100) and SiO2 as reference standards for C and O coverage. Room temperature REELS core loss intensity analysis after sample insertion reveals carbon at fractional monolayer coverage. We have established the REELS detection limit for carbon coverage to be 5±2% of a monolayer. A study of temperature-dependent hydrocarbon desorption from hydrogen-terminated Si(100) reveals the absence of carbon on the surface at temperatures greater than 200°C. This indicates the feasibility of epitaxial growth following an in situ low-temperature cleaning and also indicates the power of REELS as an in situ technique for assessment of surface cleanliness.

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Data Processing for Atomic Resolution Electron Energy Loss Spectroscopy

Microscopy and Microanalysis ◽

10.1017/s1431927612000244 ◽

2012 ◽

Vol 18 (4) ◽

pp. 667-675 ◽

Cited By ~ 69

Author(s):

Paul Cueva ◽

Robert Hovden ◽

Julia A. Mundy ◽

Huolin L. Xin ◽

David A. Muller

Keyword(s):

Energy Loss ◽

Electron Energy ◽

Electron Energy Loss Spectroscopy ◽

Principal Component ◽

Power Laws ◽

Atomic Resolution ◽

Background Error ◽

Background Estimation ◽

Electron Microscopes ◽

Electron Energy Loss

AbstractThe high beam current and subangstrom resolution of aberration-corrected scanning transmission electron microscopes has enabled electron energy loss spectroscopy (EELS) mapping with atomic resolution. These spectral maps are often dose limited and spatially oversampled, leading to low counts/channel and are thus highly sensitive to errors in background estimation. However, by taking advantage of redundancy in the dataset map, one can improve background estimation and increase chemical sensitivity. We consider two such approaches—linear combination of power laws and local background averaging—that reduce background error and improve signal extraction. Principal component analysis (PCA) can also be used to analyze spectrum images, but the poor peak-to-background ratio in EELS can lead to serious artifacts if raw EELS data are PCA filtered. We identify common artifacts and discuss alternative approaches. These algorithms are implemented within the Cornell Spectrum Imager, an open source software package for spectroscopic analysis.

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A New High Performance Electron Energy Loss Spectrometer for use with Monochromated Microscopes

Microscopy and Microanalysis ◽

10.1017/s1431927600030610 ◽

2001 ◽

Vol 7 (S2) ◽

pp. 908-909

Author(s):

H.A. Brink ◽

M. Barfels ◽

B. Edwards ◽

P. Burgner

Keyword(s):

Energy Loss ◽

Electron Energy ◽

Energy Resolution ◽

Optical Design ◽

Electron Source ◽

High Voltage Power Supply ◽

Electron Energy Loss Spectrometer ◽

Electron Microscopes ◽

Electron Energy Loss ◽

Better Than

A new type of electron energy loss spectrometer for use with monochromated microscopes is presented. The energy resolution of the spectrometer is better than 0.100 eV. A completely new electron optical design with a number of extra optical elements and advanced tuning software makes it possible to correct spectrum aberrations to 4th order, which increases sensitivity and collection angles. New high-stability electronics make it possible to maintain energy resolution over a period of several minutes in a practical laboratory environment.The energy resolution of Transmission Electron Microscopes (TEMs) equipped with electron energy loss spectrometers is determined by a combination of the energy spread of the electron source, the stability of the microscope’s high voltage power supply, and the energy resolution of the spectrometer. Commercial microscopes usually employ electron sources with an energy distributions of around 0.5 eV or more (FWHM), limiting the energy ultimate energy resolution that can be achieved. Recently FEI constructed a special 200 kV TEM with a built-in monochromator which makes it possible to monochromize the electron source to better than 0.100 eV. A prototype of the presented spectrometer has been installed on this microscope.

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