scholarly journals Holography: application to high-resolution imaging

Microscopy ◽  
2020 ◽  
Author(s):  
Takeshi Kawasaki ◽  
Yoshio Takahashi ◽  
Toshiaki Tanigaki
Keyword(s):  
High Resolution ◽  
High Precision ◽  
Functional Materials ◽  
Electron Holography ◽  
High Resolution Imaging ◽  
Nanometer Resolution ◽  
Powerful Technique ◽  
Resolution Electron ◽  
Resolution Imaging ◽  
Electron Microscopes

Abstract Electron holography was invented for correcting aberrations of the lenses of electron microscopes. It was used to observe the atomic arrangements in crystals after decades of research. Then it was combined with a hardware aberration corrector to enable high-resolution and high-precision analysis. Its applications were further extended to magnetic observations with sub-nanometer resolution. High-resolution electron holography has become a powerful technique for observing electromagnetic distributions in functional materials.

Imaging of ferroelectric domain walls by electron holography

1992 ◽  
Vol 50 (1) ◽  
pp. 246-247
Author(s):  
Xiao Zhang
Keyword(s):  
Magnetic Field ◽  
High Resolution ◽  
Domain Walls ◽  
Ferroelectric Domain ◽  
Object Wave ◽  
Electron Holography ◽  
High Resolution Imaging ◽  
Quantitative Measurements ◽  
Resolution Imaging ◽  
Electron Microscopes

Electron holography has recently been available to modern electron microscopy labs with the development of field emission electron microscopes. The unique advantage of recording both amplitude and phase of the object wave makes electron holography a effective tool to study electron optical phase objects. The visibility of the phase shifts of the object wave makes it possible to directly image the distributions of an electric or a magnetic field at high resolution. This work presents preliminary results of first high resolution imaging of ferroelectric domain walls by electron holography in BaTiO3 and quantitative measurements of electrostatic field distribution across domain walls.

Alternative approaches to ultra-high resolution imaging

1991 ◽  
Vol 49 ◽  
pp. 650-651
Author(s):  
J.M. Cowley
Keyword(s):  
High Resolution ◽  
High Voltage ◽  
High Resolution Electron Microscopy ◽  
Crystal Defects ◽  
High Resolution Imaging ◽  
General Applicability ◽  
Resolution Electron ◽  
Radiation Resistant ◽  
Resolution Imaging ◽  
Alternative Approaches

By extrapolation of past experience, it would seem that the future of ultra-high resolution electron microscopy rests with the advances of electron optical engineering that are improving the instrumental stability of high voltage microscopes to achieve the theoretical resolutions of 1Å or better at 1MeV or higher energies. While these high voltage instruments will undoubtedly produce valuable results on chosen specimens, their general applicability has been questioned on the basis of the excessive radiation damage effects which may significantly modify the detailed structures of crystal defects within even the most radiation resistant materials in a period of a few seconds. Other considerations such as those of cost and convenience of use add to the inducement to consider seriously the possibilities for alternative approaches to the achievement of comparable resolutions.

Novel lanthanide–polymer complexes for dye-free dual modal probes for MRI and fluorescence imaging

2015 ◽  
Vol 6 (46) ◽  
pp. 7949-7957 ◽  
Author(s):  
Fangyi Cao ◽  
Tongcun Huang ◽  
Yifei Wang ◽  
Fei Liu ◽  
Lumin Chen ◽  
...  
Keyword(s):  
High Resolution ◽  
Fluorescence Imaging ◽  
High Resolution Imaging ◽  
Polymer Complexes ◽  
Powerful Technique ◽  
Resolution Imaging

High-resolution imaging is a powerful technique in theranostics and staging of tumors.

Imaging of the crotoxin crystal in vitreous ice at 3.9 Å resolution

1987 ◽  
Vol 45 ◽  
pp. 646-647
Author(s):  
L. L. Degn
Keyword(s):  
High Resolution ◽  
Crystallographic Analysis ◽  
Specimen Preparation ◽  
High Resolution Imaging ◽  
Technical Problems ◽  
Resolution Electron ◽  
Resolution Imaging ◽  
Diffraction Patterns ◽  
Crotalus Durissus ◽  
Complex Crystal

The crotoxin complex is a 24,500 dalton neurotoxic protein isolated from the venom of the Brazilian rattlesnake Crotalus durissus terrificus. The crotoxin complex crystallizes as thin crystals suitable for high resolution 3-D reconstruction by electron crystallographic analysis. High resolution imaging of an untilted crotoxin complex crystal embedded in glucose has been reported. Presented here is high resolution (3.9 Å) imaging of an untilted crotoxin complex crystal embedded in vitreous ice.Several technical problems are involved in the collection of high resolution electron crystallographic data for 3-D reconstruction. First, the specimen should be as flat as possible on the grid since bending due to specimen preparation or due to beam-induced movement may cause smeared reflections in electron diffraction patterns or optical diffractograms, a phenomenon that is particularly noticeable in highly tilted specimens.

High-resolution imaging of symmetric tilt and mixed character boundaries in Al

1990 ◽  
Vol 48 (4) ◽  
pp. 336-337
Author(s):  
M. Shamzuzzoha ◽  
P.A. Deymier ◽  
David J. Smith
Keyword(s):  
High Resolution ◽  
Grain Boundary ◽  
Grain Boundaries ◽  
Thin Foil ◽  
Polycrystalline Materials ◽  
Voltage Electron ◽  
Symmetric Tilt ◽  
Resolution Electron ◽  
Resolution Imaging ◽  
Electron Microscopes

The determination of the core structure of grain boundaries is central to a better understanding of the properties of polycrystalline materials. With the recent advent of intermediate-voltage electron microscopes (300-400kV), it is possible to obtain atomic-resolution images of grain boundaries in many metals - for example, the atomic structure of periodic grain boundaries in selected metals has been studied. Our knowledge of materials properties can be further enhanced by investigating more complex, arbitrarily misoriented grain boundaries. In this paper, we will report HREM imaging of a symmetric tilt low-angle grain boundary and a twist-and-tilt (mixed character) grain boundary in Al.The Al bicrystals used in this study were produced by cross-rolling and annealing methods described in detail elsewhere. Thin foil specimens of 3mm diameter containing specific boundaries were obtained by spark-cutting and subsequent electropolishing in 73% methanol, 25% nitric acid and 2% hydrochloric acid. HREM was performed with a JEM-4000EX operated at 400kV, using axial illumination and without an objective aperture. High-resolution electron micrographs were recorded near the optimum defocus, typically at a magnification of 500,000 times.

Digital processing of high-resolution electron holograms

1993 ◽  
Vol 51 ◽  
pp. 1066-1067
Author(s):  
E. Völkl ◽  
L. F. Allard
Keyword(s):  
High Resolution ◽  
Ccd Camera ◽  
Digital Processing ◽  
Ferroelectric Material ◽  
Electron Holography ◽  
Photographic Material ◽  
Resolution Electron ◽  
Electron Image ◽  
Resolution Imaging ◽  
Conventional Microscopy

Electron Holography has been shown to be an useful tool in high resolution imaging for obtaining more information from the electron image than is possible in conventional microscopy. In our laboratory we presently record our images on photographic material, and then digitize them by using a 4096 pixel line scan by EKTRON. Digitizing photographic material and correcting for its nonlinearities is a time consuming process which will soon be alleviated by the installation of the GATAN retractable slow-scan CCD-camera. Both camera and microscope will be operated from a Macintosh computer using the software “Digital Micrograph®” and “Advanced Acquisition®”, the first of which is used already for image processing of our negatives.From an electron hologram, e.g. an hologram of a PMN ferroelectric material (FIG. 1a), the diffraction pattern of the object (FIG. 1b) can be obtained and evaluated from areas as small as one unit cell.

Electron-beam-induced 3-D epitaxy Of TiO on TiO2

1988 ◽  
Vol 46 ◽  
pp. 684-685
Author(s):  
M. R. McCartney
Keyword(s):  
High Resolution ◽  
Transition Metal Oxides ◽  
Three Dimensional ◽  
High Resolution Electron Microscopy ◽  
High Resolution Imaging ◽  
Metallic Oxide ◽  
Resolution Electron ◽  
Resolution Imaging ◽  
Modified Surface ◽  
Electron Stimulated Desorption

It is well-known that the surfaces of maximally-valent transition-metal oxides should be particularly susceptible to electron-stimulated desorption of oxygen under the conditions prevailing in high-resolution electron microscopy (HREM). Indeed, it has been observed that lattice fringes corresponding to TiO have developed on the surfaces of crystals of rutile, TiO2. Fig. 1a shows the modified surface of a rutile crystal tilted to (001)-projection with extensive regions of disorder and small crystallites of reduced (metallic) oxide at the edge; fig. 1b shows TiO2 in a [010]-projection with crystals of TiO in -projection. By combining the techniques of high-resolution imaging, optical diffractogram (ODM) analysis, and computer modeling of crystal structure, a three-dimensional epitaxy for the growth of TiO on TiO2 can be proposed.

scholarly journals High-resolution imaging of catalytic activity of a single graphene sheet using electrochemiluminescence microscopy

2021 ◽  
Vol 12 (13) ◽  
pp. 4794-4799
Author(s):  
Hui Zhu ◽  
Dechen Jiang ◽  
Jun-Jie Zhu
Keyword(s):  
Catalytic Activity ◽  
High Resolution ◽  
Graphene Sheet ◽  
Electrocatalytic Activity ◽  
High Resolution Imaging ◽  
Nanometer Resolution ◽  
Resolution Imaging

High spatial electrochemiluminescence microscopy is established to map the electrocatalytic activity of a single graphene sheet with a nanometer resolution.

Development of a 1MV-Field-Emission Electron Microscope II. Performance

2000 ◽  
Vol 6 (S2) ◽  
pp. 1140-1141
Author(s):  
T. Kawasaki ◽  
T. Yoshida ◽  
M. Gorai ◽  
T. Akashi ◽  
I. Matsui ◽  
...  
Keyword(s):  
High Resolution ◽  
Chromatic Aberration ◽  
Material Structure ◽  
Electron Holography ◽  
High Resolution Imaging ◽  
Electron Wave ◽  
Lattice Image ◽  
Overall Stability ◽  
Spacing Lattice ◽  
Resolution Imaging

The development of increasingly coherent and penetrating electron beams in electron microscopy will hasten progress in such fields as high resolution imaging, electron holography, and material structure investigation. Now that we have completed the development of the 1MV-FE- TEM (H-1000FT), we report its performance from the viewpoint of coherent illumination.We observed thin films of gold in testing the high-resolution performance of H-1000FT.Crystal lattice fringes are formed from the interference between Bragg diffracted electron waves. In TEM observation of the films, the visibility of the fringes depends on the coherence of the electron wave and the overall stability of the microscope. Here, we calculated chromatic aberration-limited resolution d, given by ∼-(Δ ƛ)1/2, to be ∼ 0.6 Å (Δ:focus spread). We then slightly tilted the illumination to partially escape from the chromatic effect and to enable us to a shorter spacing lattice image. Figure 1 shows a lattice fringe image we obtained for a Au thin film, in which lattice fringes of 0.498 Å are clearly visible.

Surface Structures and Rearrangements in Oxides

1990 ◽  
Vol 183 ◽  
Author(s):  
M. R. Mccartney ◽  
David J. Smith
Keyword(s):  
High Resolution ◽  
Electron Irradiation ◽  
High Vacuum ◽  
Ultra High Vacuum ◽  
Electron Dose ◽  
Dose Rates ◽  
Resolution Electron ◽  
Resolution Imaging ◽  
Current Densities ◽  
Electron Microscopes

AbstractElectron-beam-induced surface reactions and rearrangements have been observed for a number of oxides including MgO, TiO2, SrTiO3 and SnO2 using conventional and ultra-high-vacuum high-resolution electron microscopes. Electron irradiation of TiO2 resulted in a variety of effects including reduction, re-oxidation and amorphization. SnO2 was observed to form facets readily during high-resolution imaging but it was stable against reduction except when exposed to extreme current densities which caused the formation of metallic tin crystals. Electron irradiation of MgO under UHV conditions resulted in the formation of facetted pits. The surfaces of SrTiO3 were stable for moderate electron dose rates but rapidly amorphized when irradiated at extreme current densities.

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