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Related papers: X-ray diffraction from smectic multilayers: crosso…

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A dynamic light scattering study of director-layer fluctuations in the antiferroelectric smectic-ZA phase of the ferroelectric nematic liquid crystal DIO is reported. The dynamics are consistent with the distinctive feature of the ZA phase…

Nowadays powerful X-ray sources like synchrotrons and free-electron lasers are considered as ultimate tools for probing microscopic properties in materials. However, the correct interpretation of such experiments requires a good…

Materials Science · Physics 2018-02-28 B. Ruta , F. Zontone , Y. Chushkin , G. Baldi , G. Pintori , G. Monaco , B. Rufflé , W. Kob

The location of the beam focus when monochromatic x-ray radiation is diffracted by a thin bent crystal is predicted by "crystal lens equation". We derive this equation in a general form valid for Bragg and Laue geometries. This equation has…

Optics · Physics 2022-01-07 Jean-Pierre Guigay , Manuel Sanchez del Rio

Using molecular dynamics simulation, we study structural and dynamical heterogeneities at melting in two-dimensional one-component systems with 36000 particles. Between crystal and liquid we find intermediate hexatic states, where the…

Statistical Mechanics · Physics 2010-04-07 Hayato Shiba , Akira Onuki , Takeaki Araki

Coherent diffraction imaging enables the imaging of individual defects, such as dislocations or stacking faults, in materials.These defects and their surrounding elastic strain fields have a critical influence on the macroscopic properties…

Using coherent x-ray scattering, we evidenced atomic step roughness at the [111] vicinal surface of a silicon monocrystal of 0.05 degree miscut. Close to the (1/2 1/2 1/2) anti-Bragg position of the reciprocal space which is particularly…

Materials Science · Physics 2009-08-12 F. Livet , G. Beutier , M. de Boissieu , S. Ravy , F. Picca , D. Le Bolloc'h , V. Jacques

Diffraction gratings with large angular dispersion rates are central to obtaining high spectral resolution in grating spectrometers operating over a broad spectral range from infrared to soft-x-ray domains. The greatest challenge is of…

Optics · Physics 2021-05-18 Yuri Shvyd'ko

Smectic liquid crystals are materials formed by stacking deformable, fluid layers. Though smectics prefer to have flat, uniformly-spaced layers, boundary conditions can impose curvature on the layers. Since the layer spacing and curvature…

Differential Geometry · Mathematics 2007-05-23 Randall D. Kamien , Christian D. Santangelo

We show that stable, freely suspended liquid crystal films can be made from the ferroelectric nematic ($\mathrm{N_F}$) phase and from the recently discovered polar, lamellar $\mathrm{SmZ_A}$ and $\mathrm{SmA_F}$ phases. The $\mathrm{N_F}$…

Using the classical density functional theory of freezing and Monte Carlo computer simulations, we explore the liquid-crystalline phase behavior of hard rectangles on flat and cylindrical manifolds. Moreover, we study the effect of a static…

Soft Condensed Matter · Physics 2018-02-19 Christoph E. Sitta , Frank Smallenburg , Raphael Wittkowski , Hartmut Löwen

The spectral-angular and angular distributions of parametric X-radiation for case of backward diffraction (particular case of Bragg geometry scheme) is discussed. It is shown that in case of Bragg geometry it is necessary to use dynamical…

High Energy Physics - Phenomenology · Physics 2007-05-23 Vladimir G. Baryshevsky , Olga M. Lugovskaya

Elastomers are artificial polymeric materials created for industrial and commercial applications. Depending on their purpose, they are performing in different species and structure modifications. Our studies focus on the systems of…

Soft Condensed Matter · Physics 2011-07-13 L. V. Elnikova

We describe a multispeckle dynamic light scattering technique capable of resolving the motion of scattering sites in cases that this motion changes systematically with time. The method is based on the visibility of the speckle pattern…

Soft Condensed Matter · Physics 2007-05-23 R. Bandyopadhyay , A. S. Gittings , S. S. Suh , P. K. Dixon , D. J. Durian

For the oblique helicoidal structure of the chiral twist-bend nematic-forming mixture of CB7CB/CB6OCB/5CB doped by light-sensitive chiral compound based on azo-fragment, two consequent states of Bragg reflection of the light in the visible…

Soft Condensed Matter · Physics 2024-04-08 H. Bogatyryova , V. Chornous , L. Lisetski , I. Gvozdovskyy

In a retroreflective scheme atomic Raman diffraction adopts some of the properties of Bragg diffraction due to additional couplings to off-resonant momenta. As a consequence, double Raman diffraction has to be performed in a Bragg-type…

Quantum Physics · Physics 2022-09-08 Sabrina Hartmann , Jens Jenewein , Sven Abend , Albert Roura , Enno Giese

Crystal truncation rods calculated in the kinematical approximation are shown to quantitatively agree with the sum of the diffracted waves obtained in the two-beam dynamical calculations for different reflections along the rod. The choice…

Other Condensed Matter · Physics 2018-01-11 Vladimir M. Kaganer

We show that smectic liquid crystals confined in_anisotropic_ porous structures such as e.g.,_strained_ aerogel or aerosil exhibit two new glassy phases. The strain both ensures the stability of these phases and determines their nature. One…

Soft Condensed Matter · Physics 2009-10-31 Brad Jacobsen , Karl Saunders , Leo Radzihovsky , John Toner

We use coherent X-rays to probe the aging dynamics of a metallic glass directly on the atomic level. Contrary to the common assumption of a steady slowing down of the dynamics usually observed in macroscopic studies, we show that the…

Materials Science · Physics 2015-10-23 Zach Evenson , Beatrice Ruta , Simon Hechler , Moritz Stolpe , Eloi Pineda , Isabella Gallino , Ralf Busch

Two systems are homometric if they are indistinguishable by diffraction. We first make a distinction between Bragg and diffuse scattering homometry, and show that in the last case, coherent diffraction can allow the diffraction diagrams to…

Materials Science · Physics 2013-09-30 Sylvain Ravy

Smectic liquid crystal films a few molecular layers thick that are freely suspended in air are used as a model system to study the coalescence of fluids in two dimensions. High-speed video microscopy is used to observe the coalescence of…

Soft Condensed Matter · Physics 2021-08-18 Z. H. Nguyen , K. Harth , A. M. Goldfain , C. S. Park , J. E. Maclennan , M. A. Glaser , N. A. Clark