Quantitative High Resolution Transmission Electron Microscopy - The Role of Space Charge in Blurring Images

1996 ◽  
Vol 466 ◽  
Author(s):  
A. M. Schwartz ◽  
J. M. Gibson ◽  
T. Zheng
Keyword(s):  
High Resolution ◽  
Space Charge ◽  
Image Matching ◽  
Charge Effect ◽  
Hrtem Image ◽  
Quantum Space ◽  
Transmission Electron ◽  
High Resolution Tem ◽  
Image Simulations

ABSTRACTWe investigate space-charge by analytic methods and Monte Carlo simulations as a possible source of blur in high-resolution TEM images. In doing so we believe to have identified a novel type of space charge effect, namely quantum space charge(QSC) effect. We predict the blur for typical HRTEM images and for electron holograms. Inclusion of this hitherto unrecognized effect in image simulations (and experimental design for HRTEM and related techniques, such as holography) should permit further progress in the critical field of quantitative HRTEM image matching as a means for atomic structure determination.

Advances in image simulation for high-resolution TEM

1995 ◽  
Vol 53 ◽  
pp. 38-39
Author(s):  
Michael A. O'Keefe
Keyword(s):  
High Resolution ◽  
Structure Determination ◽  
Incident Beam ◽  
Hrtem Image ◽  
Image Simulation ◽  
Lattice Image ◽  
Transmission Electron ◽  
High Resolution Tem ◽  
Projection Approximation

The original high-resolution transmission electron microscope (HRTEM) image simulation program was written as a tool to confirm interpretation of HRTEM images of niobium oxides. Thorough testing on known structures showed that image simulation could reliably duplicate the imaging process occurring in the HRTEM, and could thus be confidently used to interpret images of unknown structures. Mainstream application of image simulation to routine structure determination by HRTEM was ushered in by the establishment of the wide applicability of the SHRLI (simulated high-resolution lattice image) programs. Structure determination of the mineral takéuchiite by HRTEM and image simulation was the first such determination accepted by the KJCr without x-ray data. Of course, once the reliability of image simulation had been established, it was realized that the technique could be put to work for applications other than structure determination. Early on, simulations were used to explore various HRTEM imaging parameters, including specimen ionicity, validity of the projection approximation, and the resolutionlimiting effects of incident-beam convergence. Since the inception of HRTEM image simulation, its range of uses has continued to expand, and so has the number of programs available; distribution of the SHRLI code spawned improved versions as well as some new programs.

Characterization of the (0110) α-Ti/γ-TiH Interface Using High-Resolution Transmission Electron Microscopy (TEM) and Electron Energy Loss Spectroscopy (EELS)

1996 ◽  
Vol 54 ◽  
pp. 108-109
Author(s):  
M. M. Tsai ◽  
J. M. Howe
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
High Resolution ◽  
Hydrogen Atoms ◽  
Transmission Electron ◽  
High Resolution Tem ◽  
High Resolution Images ◽  
Electron Energy Loss ◽  
Image Simulations

Precipitation of γ-TiH in α-Ti-H alloys involves a hcp → fct lattice transformation with hydrogen as an interstitial diffusing element Results obtained from a previous TEM study have shown that the lengthening rate of γ-TiH is diffusionally controlled at 25°C, and possibly interfacially controlled at temperatures of 50°C and higher. Therefore, it is essential to ascertain the presence or absence of hydrogen atoms at the interface. TEM foils from a 800 ppm wt.% Ti-H alloy were analyzed using high-resolution TEM and image simulations in order to determine the effects of hydrogen on high-resolution images of the α-Ti/γ-TiH interface, and EELS was used to determine the whether the hydnde structure was fully formed up to the interface.

High Resolution Transmission Electron Microscopy at Zero Cs

1998 ◽  
Vol 4 (S2) ◽  
pp. 382-383
Author(s):  
Michael A. O'Keefe
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
High Resolution ◽  
Transfer Functions ◽  
Spherical Aberration ◽  
Objective Lens ◽  
Transmission Electron ◽  
High Resolution Tem ◽  
Model Structures ◽  
Image Simulations

Now that correctors for objective lens spherical aberration are becoming feasible, questions have been raised about the usefulness of high-resolution transmission electron microscopy at zero Cs and the possible difficulties of interpretation of such images. In general, high resolution TEM images are interpreted either by comparison with simulations from model structures or by contrast transfer functions (CTFs) to determine the weight (and sense) of spatial contributions to images from corresponding diffracted beams. At zero Cs, HREM image simulations will work, but a projected charge density theory should be used (instead of CTF theory) to interpret images. Both theories use approximations; CTF theory relies on kinematic scattering and PCD theory on zero Cs and limited defocus.

scholarly journals HRTEM image-stitching for measurement of distances

2020 ◽  
Vol 5 (1) ◽  
pp. 13-17
Author(s):  
György Zoltán Radnóczi ◽  
Zoltán Herceg ◽  
Tamás Rafael Kiss
Keyword(s):  
Electron Beam ◽  
High Resolution ◽  
Single Crystal ◽  
Image Stitching ◽  
Hrtem Image ◽  
Lattice Image ◽  
High Resolution Tem ◽  
Better Than

AbstractVery accurate measurement of distances in the order of several µm is demonstrated on a single crystal Si sample by counting the lattice fringes on stitched high resolution TEM/STEM images. Stitching of TEM images commonly relies on correspondence points found in the image, however, the nearly perfect periodic nature of a lattice image renders such a procedure very unreliable. To overcome this difficulty artificial correspondence points are created on the sample using the electron beam. An accuracy better than 1% can be reached while measuring distances in the order of 1 µm. A detailed description of the process is provided, and its usability for accurately measuring large distances is discussed in detail.

The Measurement Of Subtle Structural Changes In Yba2cu3O7-x By Processing High Resolution Tem Images

1999 ◽  
Vol 5 (S2) ◽  
pp. 196-197
Author(s):  
J.C. Barry ◽  
J.A. Alarco
Keyword(s):  
Image Processing ◽  
High Resolution ◽  
Structural Changes ◽  
Processing Method ◽  
Recent Theory ◽  
Major Focus ◽  
Image Processing Method ◽  
Transmission Electron ◽  
High Resolution Tem ◽  
Structural Modulation

Since the discovery of high temperature superconducting (HTS) ceramics there has been a great deal of discussion about theories of superconductivity. In a recent theory it has been proposed that the Tc's in these new materials are related in some way to a subtle phase separation in the structure. HTS ceramics have been studied quite intensively by high resolution transmission electron microscopy (HRTEM) and by electron diffraction (ED). In such studies the major focus invariably has been on the periodic structure of the object. However, early HRTEM work on Yba2cu3O7-x by Barry found that in addition to the crystalline order, the Yba2cu3O7-x HTS has a non-periodic structural modulation. In this work we have used an image processing method to look for subtle structural changes in Yba2cu3O7-x by measuring the bending of lattice fringes at twin planes. The image processing method is similar to the method used by Hetherington to study rigid body displacements at gold grain boundaries.

Multiple Double Cross-Section Transmission Electron Microscope Sample Preparation of Specific Sub-10 nm Diameter Si Nanowire Devices

2011 ◽  
Vol 17 (6) ◽  
pp. 889-895 ◽  
Author(s):  
Lynne M. Gignac ◽  
Surbhi Mittal ◽  
Sarunya Bangsaruntip ◽  
Guy M. Cohen ◽  
Jeffrey W. Sleight
Keyword(s):  
Electron Microscope ◽  
High Resolution ◽  
Cross Section ◽  
Transmission Electron Microscope ◽  
Focused Ion Beam ◽  
Ion Beam ◽  
Si Nanowire ◽  
Dual Beam ◽  
Transmission Electron ◽  
High Resolution Tem

AbstractThe ability to prepare multiple cross-section transmission electron microscope (XTEM) samples from one XTEM sample of specific sub-10 nm features was demonstrated. Sub-10 nm diameter Si nanowire (NW) devices were initially cross-sectioned using a dual-beam focused ion beam system in a direction running parallel to the device channel. From this XTEM sample, both low- and high-resolution transmission electron microscope (TEM) images were obtained from six separate, specific site Si NW devices. The XTEM sample was then re-sectioned in four separate locations in a direction perpendicular to the device channel: 90° from the original XTEM sample direction. Three of the four XTEM samples were successfully sectioned in the gate region of the device. From these three samples, low- and high-resolution TEM images of the Si NW were taken and measurements of the NW diameters were obtained. This technique demonstrated the ability to obtain high-resolution TEM images in directions 90° from one another of multiple, specific sub-10 nm features that were spaced 1.1 μm apart.

In-Situ Transmission Electron Microscopy and Computer Simulation Study of the Kinetics of Oxygen Loss in Yba2Cu3OZ

1989 ◽  
Vol 169 ◽  
Author(s):  
C. P. Burmester ◽  
L. T. Wille ◽  
R. Gronsky ◽  
B. T. Ahn ◽  
V. Y. Lee ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
High Resolution ◽  
Computer Simulation Study ◽  
Oxygen Loss ◽  
Domain Structures ◽  
Transmission Electron ◽  
Kinetics Of ◽  
Image Simulations

AbstractHigh resolution transmission electron microscopy during in‐situ quenching of YBa2Cu3Oz is used to study the kinetics of microdomain formation during oxygen loss in this system. Image simulations based on atomic models of oxygen‐vacancy order in the basal plane of this material generated by Monte Carlo calculations are used to interpret high resolution micrographs of the structures obtained by quenching. The observed domain structures agree well with those obtained from the simualtions.

Development of a Double Tilt Specimen Heating Holder and its Application for the Study of Phase Transformation of Si3N4 During Sintering

1997 ◽  
Vol 3 (S2) ◽  
pp. 1085-1086
Author(s):  
T. Kamino ◽  
T. Yaguchi ◽  
M. Tomita ◽  
Y. Yasutomi ◽  
K. Hidaka
Keyword(s):  
Electron Microscopy ◽  
High Resolution ◽  
Elevated Temperatures ◽  
Heating Element ◽  
High Melting ◽  
High Melting Point ◽  
Transmission Electron ◽  
High Resolution Tem ◽  
Metal Wires ◽  
Very High

The results of our previous studies revealed that the specimen heating holder with the heating elements of spiral shaped fine metal wires of high melting point enable us to observe high resolution transmission electron microscopy(TEM) images at elevated temperatures.In fact, the holder was applied for high resolution TEM study of a formation of SiC crystal at 1500°C and a surface reconstruction of Au deposited Si particle at 1000°C successfully. However, because the heating holder was single tilt type, there was a certain limitation in its application.In this paper, development of a double tilt specimen heating holder with a heating element of spiral shaped fine metal wire and its application for the study of microstructural changes of Si3N4 during sintering at very high temperature.Photograph of the newly developed double tilt specimen heating holder is shown in Fig. 1. The heating element is mounted on the electrically isolated tilting frame of the holder and the heating current is supplied via tilting rod which is also electrically isolated from other parts of the holder.

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