Quasicrystalline<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:mi mathvariant="italic">d</mml:mi></mml:math>-AlCuCo Identified as Random Tiling by Ion Channeling Combined with Particle-Induced X-Ray Emission

Zeger, Gabriele; Plachke, D.; Carstanjen, H. D.; Trebin, Hans‐Rainer

doi:10.1103/physrevlett.82.5273

Cited by 9 publications

(4 citation statements)

References 26 publications

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“…The model density is 20% too high, creating many impossibly short distances (2.2 A Ê ). The TM ordering rule ± the central point ± has been disproven (Zeger et al, 1999;Cockayne & Widom, 1998b). No meaningful experimental comparison is given in the original works.…”

Section: Early Modelsmentioning

confidence: 99%

Structure solution of the basic decagonal Al–Co–Ni phase by the atomic surfaces modelling method

Cervellino

Haibach

Steurer

2001

Acta Crystallogr Sect B

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The atomic surfaces modelling technique has been used to solve the structure of the basic Ni-rich Al±Co±Ni decagonal phase. Formula Al 70.6 Co 6.7 Ni 22.7 , space group P10, ®vedimensional unit-cell parameters: d 1 = d 4 = 4.752 (3) A Ê , d 2 = d 3 = 3.360 (2) A Ê , d 5 = 8.1710 (2) A Ê ; 12 = 34 = 69.295 , 13 = 24 = 45 , 14 = 41.410 , 23 = i5 = 90 (i = 1±4), V = 291.2 (7) A Ê 5 ; D x = 3.887 Mg m À3 . Re®nement based on |F|; 2767 unique re¯ections (|F| > 0), 749 parameters, R = 0.17, wR = 0.06. Describing the structure of quasicrystals embedded in n-dimensional superspace in principle takes advantage of ndimensional periodicity to select the minimal set of degrees of freedom for the structure. The method of modelling of the atomic surfaces yielded the ®rst fully detailed structure solution of this phase. Comparison with numerous former, less accurate models con®rms several features already derived, but adds a new essential insight of the structure and its complexity. The atoms ®ll the space forming recurrent structure motifs, which we will (generically) refer to as clusters. However, no unique cluster exists, although differences are small. Each cluster shows a high degree of structural disorder. This gives rise to a large con®gurational entropy, as much as expected in a phase which is stable at high temperature. On the other side, the cluster spatial arrangement is perfectly quasiperiodic. These considerations, corroborated by analysis of the structural relationship with neighbouring periodic phases, strongly suggest the existence of a non-local, long-range interaction term in the total energy which may be essential to the stability.

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Section: Early Modelsmentioning

confidence: 99%

Structure solution of the basic decagonal Al–Co–Ni phase by the atomic surfaces modelling method

Cervellino

Haibach

Steurer

2001

Acta Crystallogr Sect B

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“…A method that is not strictly X-ray spectroscopy is particle-induced X-ray Emission (PIXE) [41]. In this method, neutrons or other particles such as electrons are used to induce X-ray fluorescence [42]. Most applications of this method are in the field of trace elemental analysis.…”

Section: Other X-ray Methodsmentioning

confidence: 99%

More power to X‐rays: New developments in X‐ray spectroscopy

Guo¹

2009

Laser & Photonics Reviews

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Recent developments in X-ray spectroscopy in the last decade are reviewed. A specific emphasis is placed on displaying the strong natural connection between X-ray spectroscopy and materials science. Brief explanations of several X-ray spectroscopic methods are given. X-ray spectroscopic instruments such as table-top X-ray sources are discussed in detail, whereas those employing synchrotron and other sources are briefly addressed. The spectroscopic methods and results from materials investigations are reviewed according to their positions in a 3D parameter space of time, length, and energy. New experimental measurements on atoms, molecules, nanomaterials, and bulk materials that include insulators, semiconductors, metals and magnetic materials using both static and time-resolved methods are reviewed.A typical table-top experimental setup to probe a sample using an optical pump (green color beam) -X-ray probe (purple color beam) technique. The X-ray pulses are produced by femtosecond optical pulses. Two exemplary data are displayed: One is direct imaging of plasmas generated from laser evaporation of a solid target (Imaging data) and the other is an X-ray absorption spectrum of a nickel sample (USEXAS data).

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“…In either case, phason fluctuations are expected to be significant above some critical temperature. So far, numerous experimental measurements on phason-related disorders/dynamics have been attempted by various experimental techniques (Bancel 1989, Colella et al 2000, Edagawa et al 2000, Francoual et al 2003, Zeger et al 1999; however, there has been no direct evidence on where such localized atomic fluctuations take place in the real-space quasicrystal structure. This is because the local disorder/fluctuation effects are all averaged in the X-ray and other diffraction patterns, and therefore it is difficult to specify the local source for diffuse scattering.…”

Section: Phason--extra Degree Of Freedommentioning

confidence: 99%

Structure of Quasicrystals

Abe

2010

Scanning Transmission Electron Microscopy

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Quasicrystals are aperiodic solids that exhibit rotational symmetries incompatible with conventional periodic lattice order, e.g., icosahedral symmetry in three dimensions and tenfold symmetry in the plane. A revolutionary announcement of the first quasicrystal was made for a thermodynamically metastable phase in a rapidly solidified Al-Mn alloy (Shechtman et al. 1984). At present, not only metastable phases but also stable quasicrystalline phases (Dubost et al. 1986, Ohashi and Spaepen 1987, Tsai et al. 1987 are available in a variety of metallic alloys (Tsai 1999), and certain stable phases can be grown into a single grain several millimeters (Figure 14-1a (Fisher et al. 1998)) or even centimeters in size. It would appear obvious, therefore, that quasicrystals can represent a free energy minimum state at a given temperature. Some of the highly perfect quasicrystalline materials exhibit a striking diffraction pattern, see Figure 14-1b, c. There are a large number of diffraction peaks, which are aperiodically arranged and located at the ideal positions being consistent with a fivefold symmetry. Besides, a remarkable fact is that the peak sharpness appears to be comparable to that from nearly perfect crystals such as silicon, as evidenced by high-resolution synchrotron diffraction experiments.These diffraction features, in particular the sharp diffraction peaks represented by delta-functions, which had been believed to be possible only for periodic crystals, can no longer be explained according to a classical framework of incommensurate crystals. Shortly after their discovery, quasicrystal structure was discussed in relation to a rather disordered/imperfect state of solids. Representative early models are an icosahedral glass model (Stephens and Goldman 1986) that assumes only a short-range icosahedral order distributed randomly to form the solid, and the so-called Pauling's model (1986) that employs multiply twinned configurations of giant cubic crystals to generate a pseudofivefold symmetry pattern. One intuitively notices that neither of these configurations can be responsible for generating the sharp Bragg peaks. Nowadays we interpret this unique long-range aperiodic order as true quasiperiodicity (Levine and Steinhardt 1984), which is not a simple 583 S

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Quasicrystallined-AlCuCo Identified as Random Tiling by Ion Channeling Combined with Particle-Induced X-Ray Emission

Cited by 9 publications

References 26 publications

Structure solution of the basic decagonal Al–Co–Ni phase by the atomic surfaces modelling method

Structure solution of the basic decagonal Al–Co–Ni phase by the atomic surfaces modelling method

More power to X‐rays: New developments in X‐ray spectroscopy

Structure of Quasicrystals

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