White-beam synchrotron radiation study of dislocations in an Al62Cu25.5Fe12.5icosahedral quasi-crystal

Wang, Renhui; Yang, Xiangxiu; Zou, Wenming; Wang, Zhouguang; Gui, Jianian; Jiang, Jianhua

doi:10.1088/0953-8984/6/43/007

Cited by 34 publications

(9 citation statements)

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“…The Burgers vector results compare well to findings in the icosahedral phase of the system Al-Cu-Fe. Dislocations of type t 3 with twofold a 0 h % 11100 % 1i Burgers vectors [43][44][45] as well as threefold and fivefold Burgers vectors were identified. 46 Since in these studies only individual dislocations were characterized, no conclusions on the relative frequencies of occurrence of different types of Burgers vector can be drawn.…”

Section: Experimental Dislocation Analysis -Icosahedralmentioning

confidence: 99%

Dislocations in icosahedral quasicrystals

Feuerbacher

2012

Chem. Soc. Rev.

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Dislocations in quasicrystals, as a direct result of the lack of translational symmetry in these materials, possess various salient features. The Burgers vector of a dislocation in an icosahedral quasicrystal is a 6-dimensional vector, which reflects the fact that the dislocation, besides the phonon-type strain field analogous to dislocations in ordinary crystals, is associated inseparably with a further type of defect, the phasons. Phasons are critically involved in the formation and motion of dislocations in quasicrystals and govern the macroscopic plastic behaviour of these materials. In this article the properties of dislocations in icosahedral quasicrystals are comprehensively reviewed, starting from a continuum-mechanical description, via core-structure simulation, to their full experimental characterization. The experimental results presented address the icosahedral phases in the well explored systems Al-Pd-Mn and Zn-Mg-Dy.

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Section: Experimental Dislocation Analysis -Icosahedralmentioning

confidence: 99%

Dislocations in icosahedral quasicrystals

Feuerbacher

2012

Chem. Soc. Rev.

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“…For example, the full information about 6D Burgers vector B of dislocations can be acquired by the de-focus CBED technique [15], the diffraction contrast imaging combined with image simulation [16] and the HRTEM technique with Fourier analysis [17]. As an extremely important complementary technique, x-ray topography (XRT) is mostly employed on defect characterization in a nearly perfect sample of large size in a non-destructive way [18][19][20][21][22][23][24][25][26][27][28][29][30][31][32][33]. This technique has also been used to characterize the defects in QCs, such as dislocations [23] and spherical inclusions [22,[24][25][26][27][28][29][30][31][32], using advanced white and monochromatic beam synchrotron radiation sources.…”

Section: Introductionmentioning

confidence: 99%

Investigation of defects in Al–Pd–Mn icosahedral quasicrystals by simulation of x-ray topography images

Jia-Yan

Wang

2008

J. Phys. D: Appl. Phys.

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The simulation of the diffraction contrast in x-ray topography has been extended from conventional crystals to quasicrystals (QCs). Case studies are presented for the investigation of two kinds of typical defects, i.e. spherical inclusions and straight dislocations, in an Al–Pd–Mn icosahedral QC using the extended program. The good agreement between the simulated and experimental images for spherical inclusions validates the extension. The systematic simulation for straight dislocations employing both phonon and phason strain fields illustrates not only the contrast dependences on various parameters, i.e. Burgers vector, diffraction vector, wavelength, deviation from exact Bragg diffraction, etc, but also the important contribution from the phason component, which is peculiar for QCs and normally makes the experimental analysis much more complex. The calculation can be applied to any defect in QCs in general and be of help in the defect characterization by matching with the experimental images, as in conventional crystals.

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Section: } 1 Introductionmentioning

confidence: 99%

“…It permits the determination of the full Burgers vector, that is not only its direction but also its magnitude. Using a white-beam synchrotron radiation technique, Wang et al (1994) determined the direction of the Burgers vector of a long dislocation in an icosahedral Al± Cu± Fe quasicrystal.All these techniques can be applied only under certain conditions. The CBED technique requires an isolated dislocation, having a relatively small angle of intersection with the specimen foil.…”

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Determination of the Burgers vector of dislocations in icosahedral quasicrystals by a high-resolution lattice-fringe technique

Yang¹,

Wang²,

Feuerbacher³

et al. 2000

Philosophical Magazine Letters

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A technique for the determination of the full six-dimensional Burgers vector characterizing a dislocation in an icosahedral quasicrystal is presented. It is based on the lattice-fringe analysis of two high-resolution transmission electron microscopy images taken at two di erent sample orientations. As an example we present the analysis of a dislocation in a bent icosahedral Al± Pd± Mn quasicrystal. We obtained a Burgers vector BˆA 0 ‰¡2; 0; 3; ¡2; 3; 0Š where A 0ˆ0 :645 nm is the six-dimensional hyperlattice constant. This result is consistent with previous results obtained by di raction contrast analysis and convergent-beam electron di raction techniques. } 1. INTRODUCTIONSince the discovery of stable quasicrystals (Sainf ort and Dubost 1986, Tsai et al. 1990) many e orts have been devoted to the study of defects, especially dislocations, in this class of materials. A number of di erent techniques for the determination of Burgers vectors of dislocations in quasicrystals have been presented. Wollgarten et al. (1991) and Feng and Wang (1994) developed a di raction contrast analysis technique, which by observing of dislocation contrast extinction for certain di raction vectors allows the determination of the direction of the Burgers vector in sixdimensional reference space. The defocused convergent-beam electron di raction (CBED) technique was generalized for the analysis of dislocations in quasicrystals by Wang and Dai (1993). It permits the determination of the full Burgers vector, that is not only its direction but also its magnitude. Using a white-beam synchrotron radiation technique, Wang et al. (1994) determined the direction of the Burgers vector of a long dislocation in an icosahedral Al± Cu± Fe quasicrystal.All these techniques can be applied only under certain conditions. The CBED technique requires an isolated dislocation, having a relatively small angle of intersection with the specimen foil. For the white-beam synchrotron radiation technique, owing to the lower spatial resolution, extended specimen areas of uniform orientation containing only a few dislocations are required. All the techniques described fail for dislocations lying at end-on orientation in a specimen.High-resolution transmission electron microscopy (HRTEM) is a powerful technique to study the structure of defects for both crystalline and quasicrystalline phases at a close to atomic resolution level. A lattice-f ringe analysis of high-resolution images can be used for the determination of a Burgers vector of an end-on oriented dislocation as will be described in } 2. Such a technique was applied earlier in a pioneering work by Devaud-R zepski et al. (1990) for the analysis of a dislocation in an icosahedral Al± Cu± Fe quasicrystal. These workers performed a lattice-f ringe analysis of a single high-resolution image. This procedure did not provide enough information for the determination of the full Burgers vector. Two remaining unknowns could only be determined by making the additional assumption that the Burgers vector has a minimum ...

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White-beam synchrotron radiation study of dislocations in an Al₆₂Cu_25.5Fe_12.5icosahedral quasi-crystal

Cited by 34 publications

References 9 publications

Dislocations in icosahedral quasicrystals

Dislocations in icosahedral quasicrystals

Investigation of defects in Al–Pd–Mn icosahedral quasicrystals by simulation of x-ray topography images

Determination of the Burgers vector of dislocations in icosahedral quasicrystals by a high-resolution lattice-fringe technique

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