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O. Scherzer

Bio: O. Scherzer is an academic researcher. The author has contributed to research in topics: Contrast transfer function & Aperture. The author has an hindex of 3, co-authored 5 publications receiving 1277 citations.

Papers
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Journal ArticleDOI
TL;DR: The resolving power of the electron microscope and the contrast in the image are calculated for different conditions of focusing, illumination and aperture as mentioned in this paper, which can change the limit of resolution by a factor of about 3.
Abstract: The resolving power of the electron microscope and the contrast in the image are calculated for different conditions of focusing, illumination and aperture. These conditions can change the limit of resolution by a factor of about 3. The contrast in the image of an atom is appreciably increased by defocusing and spherical aberration. Nevertheless, the contrast improves when the numerical value of the aberration constant is diminished. The effect of different methods of spherical correction is discussed briefly.

854 citations

Journal ArticleDOI
TL;DR: Chromatische and spharischen Aberration sind unvermeidbare Fehler der raumladungsfreien Elektronenlinse as mentioned in this paper.
Abstract: Chromatische und spharische Aberration sind unvermeidbare Fehler der raumladungsfreien Elektronenlinse. Verzeichnung (Zerdehnung wie Zerdrehung) und (alle Arten von) Koma lassen sich prinzipiell beseitigen. Durch die Unvermeidbarkeit der spharischen Aberration ist eine praktische, nicht aber eine prinzipielle Schranke fur das Auflosungsvermogen der Elektronenmikroskope gegeben.

437 citations

Journal ArticleDOI
TL;DR: In this paper, the Rechnungen werden im Anschlus an eine Arbeit von A. Sommerfeld durchgefuhrt, e.g., the Intensitat der bei der Bremsung von Protonen am nackten Kern zu erwartenden Rontgenstrahlung berechnet.
Abstract: Ubersicht: Die Rechnungen werden im Anschlus an eine Arbeit von A. Sommerfeld2) durchgefuhrt. § 1 erbringt den Nachweis der Vollstandigkeit des dort verwendeten Orthogonalsystems unter der Voraussetzung, das die polaren Eigenfunktionen ein vollstandiges System bilden. § 2 behandelt den Einflus der Masse und des Vorzeichens der Ladung auf die Ausstrahlung. In § 3 wird die Intensitat der bei der Bremsung von Protonen am nackten Kern zu erwartenden Rontgenstrahlung berechnet. § 4 enthalt die Berechnung der Richtungsverteilung der gebremsten Elektronen unter Vernachlassigung der Relativitatskorrektion. Am Schlusse der Arbeit werden die Ergebnisse einer relativistischen Behandlung des Problems mitgeteilt.

35 citations

Book
01 Jan 1934
TL;DR: Brüche and Scherzer as discussed by the authors described the behavior of electrics in terms of the way they behave in many respects like light: they may travel in straight lines; they may be refracted in electric or magnetic fields, may be focused as by a lens in suitably graded fields, or may be caused to produce interference patterns in properly disposed apparatus.
Abstract: ELECTRONS behave in many respects like light. They may travel in straight lines; may be ‘refracted’ in electric or magnetic fields, may be focused as by a lens in suitably graded fields, or may be caused to produce interference patterns in properly disposed apparatus. These are the matters which the authors of this book have chosen for their topic, and which they have elaborated with most praiseworthy attention to detail and extreme completeness of reference.Geometrische Elektronenoptik: Grundlagen und Anwendungen.Von E. Brüche O. Scherzer. Pp. xii + 332. (Berlin: Julius Springer, 1934.) 28.40 gold marks.

1 citations


Cited by
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Journal ArticleDOI
TL;DR: Water is the most abundant component of biological material, but it is systematically excluded from conventional electron microscopy, because water evaporates rapidly under the vacuum conditions of an electron microscope.
Abstract: Water is the most abundant component of biological material, but it is systematically excluded from conventional electron microscopy. This is because water evaporates rapidly under the vacuum conditions of an electron microscope. Cryoelectron microscopy has long been seen as a possible avenue to overcome this limitation, but until recently the direct observation of frozen-hydrated specimens was relatively unsuccessful because of a number of serious difficulties. These were, in particular, due to the absence of a good cryospecimen holder, the inherently low contrast of hydrated specimens and the structural damage due to ice crystals formed during freezing. As a consequence, the cryomethods which have flourished in electron microscopy during the last 20 years were not aimed at preserving the hydration of the specimen in the electron microscope. Freezing was only used as an aid to preparation. The objects ultimately observed in the electron microscope were dry and at room temperature. Such cryomethods have recently been reviewed in detail (Robards and Sleytr 1985).

2,137 citations

Journal ArticleDOI
TL;DR: In this paper, the authors introduce the fundamentals of TEM and its applications in structural determination of shape-controlled nanocrystals and their assemblies, and demonstrate in situ TEM for characterizing and measuring the thermodynamic, electric, and mechanical properties of individual nanostructures, from which the structure−property relationship can be registered with a specific nanoparticle/structure.
Abstract: The physical and chemical properties of nanophase materials rely on their crystal and surface structures. Transmission electron microscopy (TEM) is a powerful and unique technique for structure characterization. The most important application of TEM is the atomic-resolution real-space imaging of nanoparticles. This article introduces the fundamentals of TEM and its applications in structural determination of shape-controlled nanocrystals and their assemblies. By forming a nanometer size electron probe, TEM is unique in identifying and quantifying the chemical and electronic structure of individual nanocrystals. Electron energy-loss spectroscopy analysis of the solid-state effects and mapping the valence states are even more attractive. In situ TEM is demonstrated for characterizing and measuring the thermodynamic, electric, and mechanical properties of individual nanostructures, from which the structure−property relationship can be registered with a specific nanoparticle/structure.

1,980 citations

Journal ArticleDOI
08 Aug 2002-Nature
TL;DR: The implementation of a computer-controlled aberration correction system in a scanning transmission electron microscope, which is less sensitive to chromatic aberration, is reported here and allows dynamic imaging of single atoms, clusters of a few atoms, and single atomic layer ‘rafts' of atoms coexisting with Au islands on a carbon substrate.
Abstract: Following the invention of electron optics during the 1930s, lens aberrations have limited the achievable spatial resolution to about 50 times the wavelength of the imaging electrons. This situation is similar to that faced by Leeuwenhoek in the seventeenth century, whose work to improve the quality of glass lenses led directly to his discovery of the ubiquitous "animalcules" in canal water, the first hints of the cellular basis of life. The electron optical aberration problem was well understood from the start, but more than 60 years elapsed before a practical correction scheme for electron microscopy was demonstrated, and even then the remaining chromatic aberrations still limited the resolution. We report here the implementation of a computer-controlled aberration correction system in a scanning transmission electron microscope, which is less sensitive to chromatic aberration. Using this approach, we achieve an electron probe smaller than 1 A. This performance, about 20 times the electron wavelength at 120 keV energy, allows dynamic imaging of single atoms, clusters of a few atoms, and single atomic layer 'rafts' of atoms coexisting with Au islands on a carbon substrate. This technique should also allow atomic column imaging of semiconductors, for detection of single dopant atoms, using an electron beam with energy below the damage threshold for silicon.

836 citations

Journal ArticleDOI
TL;DR: In this article, the use of a high-angle annular detector in a scanning transmission electron microscope is shown to provide incoherent images of crystalline materials with strong compositional sensitivity.

791 citations

Journal ArticleDOI
01 Dec 1988-Nature
TL;DR: In this paper, a high-angle detector in a scanning transmission electron microscope was used to obtain high atomic-number contrast for single crystals of the high-transition-temperature superconductors YBa2Cu3O7-x and ErBa2cu3O 7-x.
Abstract: Conventional high-resolution electron microscopy uses the phase-contrast method1, in which the diffracted beams emerging from the sample are recombined on the viewing screen of the microscope. The resultant contrast depends on the relative phases of the diffracted beams, which is sensitive to microscope and sample parameters, so that images must be interpreted by means of simulation, and defect models are somewhat empirical. By using a high-angle detector in a scanning transmission electron microscope, these problems may be avoided and high atomic-number contrast may be obtained. Here we present results of this technique applied to single crystals of the high-transition-temperature superconductors YBa2Cu3O7–x and ErBa2Cu3O7–x. The heavy-atom planes are directly imaged as bright lines, and the probable structure of an observed defect is directly inferred from its image.

621 citations