LXVIII. Direct observations of the arrangement and motion of dislocations in aluminium

Hirsch, P. B.; Horne, R.W.; Whelan, M. J.

doi:10.1080/14786435608244003

Cited by 430 publications

(80 citation statements)

References 9 publications

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“…Transmission Electron Microscopy (TEM) and dislocations are linked in this manner ever since the first images of dislocations were recorded in electron microscopes 50 years ago [1][2][3]. The inner material's structure became accessible revealing dislocations that could be studied and very successfully related to materials properties.…”

Section: Introductionmentioning

confidence: 99%

Sub-angstrom imaging of dislocation core structures: how well are experiments comparable with theory?

Kisielowski

Freitag²,

et al. 2006

Philosophical Magazine

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During the past 50 years Transmission Electron Microscopy (TEM) has evolved from an imaging tool to a quantitative method that approaches the ultimate goal of understanding the atomic structure of materials atom by atom in three dimensions both experimentally and theoretically. Today's TEM abilities are tested in the special case of a Ga terminated 30 degree partial dislocation in GaAs:Be where it is shown that a combination of highresolution phase contrast imaging, Scanning TEM, and local Electron Energy Loss Spectroscopy allows for a complete analysis of dislocation cores and associated stacking faults. We find that it is already possible to locate atom column positions with picometer precision in directly interpretable images of the projected crystal structure and that chemically different elements can already be identified together with their local electronic structure. In terms of theory, the experimental results can be quantitatively compared with ab initio electronic structure total energy calculations. By combining elasticity theory methods with atomic theory an equivalent crystal volume can be addressed. Therefore, it is already feasible to merge experiments and theory on a picometer length scale. While current experiments require the utilization of different, specialized instruments it is foreseeable that the rapid improvement of electron optical elements will soon generate a next generation of microscopes with the ability to image and analyze single atoms in one instrument with deep sub Ångstrom spatial resolution and an energy resolution better than 100 meV.

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Section: Introductionmentioning

confidence: 99%

Sub-angstrom imaging of dislocation core structures: how well are experiments comparable with theory?

Kisielowski

Freitag²,

et al. 2006

Philosophical Magazine

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“…Therefore, dynamic observation of dislocations was achieved as soon as dislocations were observed by electron microscopy in 1956. 11) Since then, electron microscopy has been the only technique for in-situ observation of plastic deformation or phase transformation. However, the extreme thinness of the specimens required in electron microscopy may lead to conclusions that are invalid for bulk materials.…”

Section: Methods Of Live X-ray Topographymentioning

confidence: 99%

“…This question was solved by the development of the dislocation theory 10) in the 1950's; the fact that crystals were deformed easily was understood by introducing the concept of linear imperfections, called "dislocations", in crystal lattices. Dislocations were observed for the first time by electron microscopy in 1956 11) and by X-ray topography in 1958. [12][13][14][15] X-ray diffraction topography 16,17) is concerned with pointto-point variations in the directions and/or the intensities of X-rays diffracted by crystals.…”

Section: Introductionmentioning

confidence: 99%

Live X-Ray Topography and Crystal Growth of Silicon

Chikawa¹

1999

Jpn. J. Appl. Phys.

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Dynamic observation of crystal imperfections has been made by live topography to image diffraction topographs instantaneously, using an intense X-ray source and a video camera. With the aid of synchrotron radiation, a resolution of 6 µm was achieved using an X-ray "Saticon" camera tube having an amorphous Se-As photoconductive layer. The property of the layer made avalanche amplification possible, enabling live topography using a conventional X-ray tube. Usefulness of live topography is demonstrated by in-situ observation of crystal-melt interfaces: Dislocations exist stably at equilibrium but become unstable with deviation from equilibrium leading to a dislocation-free state. This result is explained as the reverse of spiral growth. A formation mechanism of swirl microdefects is proposed on the basis of experimental results which indicate that only vacancies are intrinsic defects in silicon.

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“…In 1939, Burgers [45] described the screw and mixed dislocations. And finally in 1956, Hirsch, Horne et Whelan [46] and Bollmann [47] observed independently dislocations in metals by using electronic microscopes. Concerning the disclinations, it is in 1904 that Lehmann [48] observed them in molecular crystals, and in 1922 that Friedel [49] gave them a physical explanation.…”

Section: Dislocation and Disclination Charges In Eulerian Latticesmentioning

confidence: 99%

Universe and Matter Conjectured as a 3-Dimensional Lattice with Topological Singularities

Gremaud¹

2016

JMP

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One fundamental problem of modern physics is the search for a theory of everything able to explain the nature of space-time, what matter is and how matter interacts. There are various propositions, as Grand Unified Theory, Quantum Gravity, Supersymmetry, String and Superstring Theories, and M-Theory. However, none of them is able to consistently explain at the present and same time electromagnetism, relativity, gravitation, quantum physics and observed elementary particles. In this paper, one summarizes the content of a new book, published in English [2] and in French [3], in which it is suggested that Universe could be a massive elastic 3D-lattice, and that fundamental building blocks of Ordinary Matter could consist of topological singularities of this lattice, namely diverse dislocation loops and disclination loops. For an isotropic elastic lattice obeying Newton's law, with specific assumptions on its elastic properties, one obtains the result that the behaviours of this lattice and of its topological defects display "all" known physics, unifying electromagnetism, relativity, gravitation and quantum physics, and resolving some longstanding questions of modern cosmology. Moreover, studying lattices with axial symmetries, represented by "colored" cubic 3D-lattices, one has identified a lattice structure whose topological defect loops coincide with the complex zoology of elementary particles, which could open a very promising field of research. Here, only main steps and principal results of the new theory are presented and discussed, without showing the mathematical concepts and developments contained in the book.

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LXVIII. Direct observations of the arrangement and motion of dislocations in aluminium

Cited by 430 publications

References 9 publications

Sub-angstrom imaging of dislocation core structures: how well are experiments comparable with theory?

Sub-angstrom imaging of dislocation core structures: how well are experiments comparable with theory?

Live X-Ray Topography and Crystal Growth of Silicon

Universe and Matter Conjectured as a 3-Dimensional Lattice with Topological Singularities

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