A Study of Grain Boundaries in High TC Superconducting Yba2Cu3O7-x Thin Films Using High Resolution Analytical Stem

1989 ◽  
Vol 169 ◽  
Author(s):  
D. H. Shin ◽  
J. Silcox ◽  
S. E. Russek ◽  
D. K. Lathrop ◽  
R. A. Buhrman
Keyword(s):  
Thin Films ◽  
High Resolution ◽  
Grain Boundaries ◽  
Scanning Transmission Electron Microscope ◽  
Atomic Resolution ◽  
High Tc ◽  
X Ray ◽  
Transmission Electron ◽  
Scanning Transmission ◽  
Edx Microanalysis

AbstractGrain boundaries in thin films of high Tc YBa2Cu3O7-x superconductors have been investigated with high resolution scanning transmission electron microscope (STEM) imaging and nanoprobe energy dispersive x-ray (EDX) analysis. Atomic resolution images indicate that the grain boundaries are mostly clean, i.e., free of a boundary layer of different phase or of segregation, and are often coherent. EDX microanalysis with a 10 Å spatial resolution also indicates no composition deviation at the grain boundaries.

Quantitative Analysis of Atomic-Resolution X-ray Maps in an Aberration- Corrected Scanning Transmission Electron Microscope with a Large Solid- Angle Detector

2012 ◽  
Vol 18 (S2) ◽  
pp. 974-975 ◽  
Author(s):  
M. Watanabe ◽  
A. Yasuhara ◽  
E. Okunishi
Keyword(s):  
Electron Microscope ◽  
Quantitative Analysis ◽  
Transmission Electron Microscope ◽  
Solid Angle ◽  
Scanning Transmission Electron Microscope ◽  
Atomic Resolution ◽  
X Ray ◽  
Transmission Electron ◽  
Scanning Transmission ◽  
Aberration Corrected

Extended abstract of a paper presented at Microscopy and Microanalysis 2012 in Phoenix, Arizona, USA, July 29 – August 2, 2012.

High-resolution backscattered electron images in the scanning electron microscope

1992 ◽  
Vol 50 (2) ◽  
pp. 1608-1609
Author(s):  
Oliver C. Wells ◽  
P.C. Cheng
Keyword(s):  
Electron Microscope ◽  
High Resolution ◽  
Scanning Electron Microscope ◽  
Transmission Electron Microscope ◽  
Scanning Transmission Electron Microscope ◽  
Atomic Resolution ◽  
Transmission Electron ◽  
Scanning Transmission ◽  
Backscattered Electron ◽  
Scanning Electron

In this discussion the words “high resolution imaging” of a solid sample in the scanning electron microscope (SEM) mean that details can be resolved that are considerably smaller than the penetration depth of the incident electron beam (EB) into the specimen. “Atomic resolution” in either the transmission electron microscope (TEM) or scanning transmission electron microscope (STEM) means that columns of atoms are resolved.Image contrasts in the backscattered electron (BSE) image are strongly affected by the specimen tilt and by the position and energy sensitivity of the BSE detector. The expression “BSE image” generally implies that the specimen is normal to the beam and the detector is above it. This shows compositional variations in the specimen with a spatial resolution limited by the spreading of the EB during the initial stages of penetration. This is similar in basic principle to the Z-Contrast method in the STEM that shows atomic resolution from a thinned single crystal mounted in the magnetic field of the focusing lens.

scholarly journals The Scanning Confocal Electron Microscope

2003 ◽  
Vol 11 (6) ◽  
pp. 8-13 ◽  
Author(s):  
Nestor J. Zaluzec
Keyword(s):  
Electron Microscope ◽  
High Resolution ◽  
Cross Section ◽  
Transmission Electron Microscope ◽  
Scanning Transmission Electron Microscope ◽  
X Ray ◽  
Careful Preparation ◽  
Transmission Electron ◽  
Scanning Transmission ◽  
Materials Research

Imaging of sub-micron , sub-surface features of thick optically dense materials at high resolution has always been a difficult and/or time consuming task in materials research. For the most part this role has been relegated to technologically complex and expensive instrumentation having highly penetrating radiation, such as the synchrotron- based Scanning Transmission X-ray Microscope (STXM) or involves the careful preparation of thin cross-section slices for study using the Transmission/Scanning Transmission Electron Microscope (TEM/STEM).

Challenges to Quantitative Multivariate Statistical Analysis of Atomic-Resolution X-Ray Spectral

2012 ◽  
Vol 18 (4) ◽  
pp. 691-698 ◽  
Author(s):  
Paul G. Kotula ◽  
Dmitri O. Klenov ◽  
H. Sebastian von Harrach
Keyword(s):  
Statistical Analysis ◽  
Multivariate Statistical Analysis ◽  
Image Data ◽  
Scanning Transmission Electron Microscope ◽  
Atomic Resolution ◽  
Multivariate Statistical ◽  
X Ray ◽  
Specific Signal ◽  
Transmission Electron ◽  
Scanning Transmission

AbstractA new aberration-corrected scanning transmission electron microscope equipped with an array of Si-drift energy-dispersive X-ray spectrometers has been utilized to acquire spectral image data at atomic resolution. The resulting noisy data were subjected to multivariate statistical analysis to noise filter, remove an unwanted and partially overlapping non-sample-specific X-ray signal, and extract the relevant correlated X-ray signals (e.g., channels with L and K lines). As an example, the Y2Ti2O7pyrochlore-structured oxide (assumed here to be ideal) was interrogated at the [011] projection. In addition to pure columns of Y and Ti, at this projection, there are also mixed 50-50 at. % Y-Ti columns. An attempt at atomic-resolution quantification is presented. The method proposed here is to subtract the non-column-specific signal from the elemental components and then quantify the data based upon an internally derivedk-factor. However, a theoretical basis to predict this non-column-specific signal is needed to make this generally applicable.

A Stem Study of P and Ge Segregation to Grain Boundaries in Si1-xGex Thin Films

1999 ◽  
Vol 557 ◽  
Author(s):  
W. Qin ◽  
D. G. Ast ◽  
T. I. Kamins
Keyword(s):  
Grain Boundaries ◽  
Secondary Ion Mass Spectrometry ◽  
Chemical Vapor ◽  
X Ray ◽  
Transmission Electron ◽  
Scanning Transmission ◽  
Equilibrium Process ◽  
Sims Analysis ◽  
Secondary Ion ◽  
Edx Microanalysis

AbstractThe segregation of phosphorus to grain boundaries in phosphorus implanted Si0.87Ge0.13 films, deposited by chemical vapor deposition (CVD), was directly observed by scanning transmission electron microscopy (STEM) with energy dispersive x-ray (EDX) microanalysis. The segregation was determined to be a thermal equilibrium process by measuring and comparing the average phosphorus concentrations at the grain boundaries in Si0.87Ge0.13 films subjected to 700, 750 or 800°C annealing, following the implantation and 1000°C annealing processes. The measured segregation energy was 0.28 eV/atom. No Ge segregation was found at grain boundaries in phosphorus implanted Si0.87Ge0.13 films by STEM x-ray microanalysis. Neither was evidence shown by STEM microanalysis that Ge segregated to grain boundaries in intrinsic Si1-xGex films with x = 0.02, 0.13 and 0.31. Secondary ion mass spectrometry (SIMS) analysis showed that these intrinsic Si1-xGex films contained 1019 to 4 × 1019/cm-3H, depending on the deposition temperature.

The High Resolution Scanning Transmission Electron Microscope

1974 ◽  
Vol 32 ◽  
pp. 316-317
Author(s):  
A. V. Crewe
Keyword(s):  
Electron Microscope ◽  
High Resolution ◽  
High Vacuum ◽  
Scanning Transmission Electron Microscope ◽  
Ultra High Vacuum ◽  
Resolving Power ◽  
Imaging Characteristics ◽  
Transmission Electron ◽  
Scanning Transmission ◽  
The Moment

The high resolution STEM is now a fact of life. I think that we have, in the last few years, demonstrated that this instrument is capable of the same resolving power as a CEM but is sufficiently different in its imaging characteristics to offer some real advantages.It seems possible to prove in a quite general way that only a field emission source can give adequate intensity for the highest resolution^ and at the moment this means operating at ultra high vacuum levels. Our experience, however, is that neither the source nor the vacuum are difficult to manage and indeed are simpler than many other systems and substantially trouble-free.

To What Extent are Inelastically Scattered Electrons Useful in the Stem?

1973 ◽  
Vol 31 ◽  
pp. 286-287 ◽  
Author(s):  
H. Rose
Keyword(s):  
Electron Microscope ◽  
High Resolution ◽  
Electron Correlation ◽  
Quantum Noise ◽  
Collection Efficiency ◽  
Scanning Transmission Electron Microscope ◽  
Electron Cloud ◽  
Scanning Time ◽  
Transmission Electron ◽  
Scanning Transmission

The scanning transmission electron microscope offers the possibility of utilizing inelastically scattered electrons. Use of these electrons in addition to the elastically scattered electrons should reduce the scanning time (dose) Which is necessary to keep the quantum noise below a certain level. Hence it should lower the radiation damage. For high resolution, Where the collection efficiency of elastically scattered electrons is small, the use of Inelastically scattered electrons should become more and more favorable because they can all be detected by means of a spectrometer. Unfortunately, the Inelastic scattering Is a non-localized interaction due to the electron-electron correlation, occurring predominantly at the circumference of the atomic electron cloud.

Description of a New High Resolution Scanning Transmission EM

1972 ◽  
Vol 30 ◽  
pp. 418-419
Author(s):  
Michael Beer ◽  
J. W. Wiggins ◽  
David Woodruff ◽  
Jon Zubin
Keyword(s):  
High Resolution ◽  
Field Emission ◽  
Energy Dispersive Spectrometer ◽  
Scanning Transmission Electron Microscope ◽  
Objective Lens ◽  
Condenser Lens ◽  
Transmission Electron ◽  
Pattern Size ◽  
Scanning Transmission ◽  
Under Construction

A high resolution scanning transmission electron microscope of the type developed by A. V. Crewe is under construction in this laboratory. The basic design is completed and construction is under way with completion expected by the end of this year.The optical column of the microscope will consist of a field emission electron source, an accelerating lens, condenser lens, objective lens, diffraction lens, an energy dispersive spectrometer, and three electron detectors. For any accelerating voltage the condenser lens function to provide a parallel beam at the entrance of the objective lens. The diffraction lens is weak and its current will be controlled by the objective lens current to give an electron diffraction pattern size which is independent of small changes in the objective lens current made to achieve focus at the specimen. The objective lens demagnifies the image of the field emission source so that its Gaussian size is small compared to the aberration limit.

Design of a new objective lens for an HB-501A STEM

1991 ◽  
Vol 49 ◽  
pp. 416-417
Author(s):  
Earl J. Kirkland ◽  
Robert J. Keyse
Keyword(s):  
High Resolution ◽  
Spherical Aberration ◽  
Scanning Transmission Electron Microscope ◽  
Dark Field ◽  
Objective Lens ◽  
Specimen Holder ◽  
Transmission Electron ◽  
Scanning Transmission ◽  
Annular Dark Field ◽  
High Resolution Microscopy

An ultra-high resolution pole piece with a coefficient of spherical aberration Cs=0.7mm. was previously designed for a Vacuum Generators HB-501A Scanning Transmission Electron Microscope (STEM). This lens was used to produce bright field (BF) and annular dark field (ADF) images of (111) silicon with a lattice spacing of 1.92 Å. In this microscope the specimen must be loaded into the lens through the top bore (or exit bore, electrons traveling from the bottom to the top). Thus the top bore must be rather large to accommodate the specimen holder. Unfortunately, a large bore is not ideal for producing low aberrations. The old lens was thus highly asymmetrical, with an upper bore of 8.0mm. Even with this large upper bore it has not been possible to produce a tilting stage, which hampers high resolution microscopy.

High-resolution x-ray imaging of small copper-rich precipitates in steels

1988 ◽  
Vol 46 ◽  
pp. 528-529
Author(s):  
J. R. Michael ◽  
K. A. Taylor
Keyword(s):  
Electron Microscopy ◽  
Thermomechanical Processing ◽  
Atom Probe ◽  
Ferrite Matrix ◽  
Scanning Transmission Electron Microscope ◽  
Probe Field ◽  
X Ray ◽  
Subsequent Transformation ◽  
Transmission Electron ◽  
Scanning Transmission

Although copper is considered an incidental or trace element in many commercial steels, some grades contain up to 1-2 wt.% Cu for precipitation strengthening. Previous electron microscopy and atom-probe/field-ion microscopy (AP/FIM) studies indicate that the precipitation of copper from ferrite proceeds with the formation of Cu-rich bcc zones and the subsequent transformation of these zones to fcc copper particles. However, the similarity between the atomic scattering amplitudes for iron and copper and the small misfit between between Cu-rich particles and the ferrite matrix preclude the detection of small (<5 nm) Cu-rich particles by conventional transmission electron microscopy; such particles have been imaged directly only by FIM. Here results are presented whereby the Cu Kα x-ray signal was used in a dedicated scanning transmission electron microscope (STEM) to image small Cu-rich particles in a steel. The capability to detect these small particles is expected to be helpful in understanding the behavior of copper in steels during thermomechanical processing and heat treatment.

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