scholarly journals Experimentally obtained and computer-simulated X-ray non-coplanar 18-beam pinhole topographs for a silicon crystal

2019 ◽  
Vol 75 (3) ◽  
pp. 483-488 ◽  
Author(s):  
Kouhei Okitsu ◽  
Yasuhiko Imai ◽  
Yoshitaka Yoda
Keyword(s):  
Silicon Crystal ◽  
Dynamical Theory ◽  
X Rays ◽  
X Ray Diffraction ◽  
X Ray ◽  
Good Agreement

Non-coplanar 18-beam X-ray pinhole topographs for a silicon crystal were computer simulated by fast Fourier transforming the X-ray rocking amplitudes that were obtained by solving the n-beam (n = 18) Ewald–Laue dynamical theory (E-L&FFT method). They were in good agreement with the experimentally obtained images captured using synchrotron X-rays. From this result and further consideration based on it, it has been clarified that the X-ray diffraction intensities when n X-ray waves are simultaneously strong in the crystal can be computed for any n by using the E-L&FFT method.

Investigation of the phase shift in X-ray forward diffraction using an X-ray interferometer

1998 ◽  
Vol 5 (3) ◽  
pp. 967-968 ◽  
Author(s):  
Keiichi Hirano ◽  
Atsushi Momose
Keyword(s):  
Phase Shift ◽  
Silicon Crystal ◽  
Dynamical Theory ◽  
Perfect Crystal ◽  
X Rays ◽  
X Ray Diffraction ◽  
X Ray ◽  
Bragg Geometry

The phase shift of forward-diffracted X-rays by a perfect crystal is discussed on the basis of the dynamical theory of X-ray diffraction. By means of a triple Laue-case X-ray interferometer, the phase shift of forward-diffracted X-rays by a silicon crystal in the Bragg geometry was investigated.

Generation and Proof of Elliptically Polarized X-Rays

1982 ◽  
Vol 37 (6) ◽  
pp. 524-527
Author(s):  
O. Brümmer ◽  
Ch. Eisenschmidt ◽  
H. R. Höche
Keyword(s):  
Phase Relation ◽  
Silicon Crystal ◽  
Dynamical Theory ◽  
X Rays ◽  
X Ray Diffraction ◽  
Wave Fields ◽  
X Ray ◽  
Polarized Waves ◽  
Angle Of Reflection ◽  
Elliptically Polarized

Abstract Using an arrangement being analogous to optics of visible light the phase relation of the mutually perpendicularly polarized wave fields are examined in the Laue case of X-ray diffraction. Bragg reflections at an angle of reflection of about 45° are used as polarizer and analyzer. The different phase relations result from different thicknesses of a wedge-shaped silicon crystal, which is placed between the polarizer and the analyzer and adjusted for the symmetric 220-CuKαl-Laue case. The determined polarization states produced by coherent excitation of both σ-polarized and π-polarized waves in the silicon crystal coincide very well with calculations of the dynamical theory of X-ray diffraction.

An algorithm for calculating diffraction profiles of 2θ scans for multiple diffraction from crystals and thin films

2014 ◽  
Vol 70 (6) ◽  
pp. 572-582
Author(s):  
Hsin-Yi Chen ◽  
Mau-Sen Chiu ◽  
Chia-Hung Chu ◽  
Shih-Lin Chang
Keyword(s):  
Initial Phase ◽  
Atomic Layer ◽  
Dynamical Theory ◽  
Far Field ◽  
X Rays ◽  
X Ray Diffraction ◽  
Multiple Diffraction ◽  
X Ray ◽  
Beam Surface ◽  
Surface Diffraction

An algorithm is developed based on the dynamical theory of X-ray diffraction for calculating the profiles of the diffracted beam,i.e.the diagrams of the intensity distributionversus2θ when a crystal is fixed at an angle of its maximum diffracted intensity. Similar to Fraunhofer (far-field) diffraction for a single-slit case, in the proposed algorithm the diffracted beam from one atomic layer excited by X-rays is described by the composition of (N+ 1) coherent point oscillators in the crystal. The amplitude and the initial phase of the electric field for each oscillator can be calculated based on the dynamical theory with given boundary conditions. This algorithm not only gives diffraction profiles but also provides the contribution of the excitation of modes when extremely asymmetric diffraction is involved in the diffraction process. Examples such as extremely asymmetric two-beam surface diffraction and three-beam surface diffraction are presented and discussed in detail.

Dynamical effects in the integrated X-ray scattering intensity from imperfect crystals in Bragg diffraction geometry. I. Semi-dynamical model

2020 ◽  
Vol 76 (1) ◽  
pp. 45-54
Author(s):  
V. B. Molodkin ◽  
S. I. Olikhovskii ◽  
S. V. Dmitriev ◽  
A. I. Nizkova ◽  
V. V. Lizunov
Keyword(s):  
Silicon Crystal ◽  
Azimuthal Angle ◽  
Dynamical Theory ◽  
Bragg Diffraction ◽  
X Ray Diffraction ◽  
X Ray ◽  
X Ray Scattering ◽  
Diffraction Geometry ◽  
Coulomb Type ◽  
Analytical Expressions

The analytical expressions for the coherent and diffuse components of the integrated reflection coefficient are considered in the case of asymmetric Bragg diffraction geometry for a single crystal of arbitrary thickness, which contains randomly distributed Coulomb-type defects. The possibility to choose the combinations of diffraction conditions optimal for characterizing defects of several types by accounting for dynamical effects in the integrated coherent and diffuse scattering intensities, i.e. primary extinction and anomalous absorption, has been analysed based on the statistical dynamical theory of X-ray diffraction by imperfect crystals. The measured integrated reflectivity dependencies of the imperfect silicon crystal on azimuthal angle were fitted to determine the diffraction parameters characterizing defects in the sample using the proposed formulas in semi-dynamical and semi-kinematical approaches.

Theoretical and Experimental Study of the Diffraction Contrast on Magnetic Domain Walls

1982 ◽  
Vol 37 (5) ◽  
pp. 419-426 ◽  
Author(s):  
M. Polcarová ◽  
J. Brádler
Keyword(s):  
Experimental Study ◽  
Single Crystals ◽  
Domain Walls ◽  
Magnetic Domain ◽  
Dynamical Theory ◽  
X Ray Diffraction ◽  
X Ray ◽  
Magnetic Domain Walls ◽  
Integrated Intensities ◽  
Good Agreement

Dynamical theory of the X-ray diffraction on a crystal containing misfit boundary was applied to the interpretation of the contrast observed in X-ray topographs on 90° magnetic domain walls in single crystals of an Fe-Si alloy. The integrated intensities were computed for several cases corresponding to the actual conditions of experiments. Good agreement of theoretical and experi­mental results was obtained.

Limits of the X-Ray Collimation by One Asymmetrical Bragg Reflection

1982 ◽  
Vol 37 (6) ◽  
pp. 519-523 ◽  
Author(s):  
◽  
H. R. Höche ◽  
J. Nieber
Keyword(s):  
Bragg Reflection ◽  
Dynamical Theory ◽  
X Rays ◽  
Optimum Conditions ◽  
X Ray Diffraction ◽  
X Ray

Abstract In connection with the production of highly collimated X-rays the study of extremely asymmetrical Bragg reflections became of interest. In this paper the so-called extended dynamical theory of X-ray diffraction will be tested experimentally. As a result of this investigations the optimum conditions for X-ray collimation by means of one asymmetrical Bragg reflection are being discussed.

Laue X-ray diffraction studies of the structural perfection of Al-doped thermomigration channels in silicon

2021 ◽  
Vol 54 (2) ◽  
pp. 588-596
Author(s):  
Andrey A. Lomov ◽  
Vasily I. Punegov ◽  
Boris M. Seredin
Keyword(s):  
Cross Sections ◽  
High Sensitivity ◽  
Dynamical Theory ◽  
X Rays ◽  
X Ray Diffraction ◽  
Structural Perfection ◽  
Laue Diffraction ◽  
X Ray ◽  
Structural Distortions ◽  
Further Development

Si(111) wafers patterned with an array of vertical 100 µm-wide Al-doped (1 × 1019 cm−3) p-channels extending through the whole wafer were studied by X-ray Laue diffraction techniques. The X-ray techniques included projection topography, and measurement of rocking curves and cross sections in the vicinity of the 02\overline 2 reciprocal space node in the double- and triple-crystal geometry, respectively. The channels are uniform along the depth of the wafer, and their structural perfection is comparable to that of the silicon matrix between the channels. Simulation of the rocking curves was performed using the methods of the dynamical theory of X-ray diffraction. The rocking-curve calculations both taking into account and neglecting the effect of the instrumental function were carried out using the Takagi–Taupin equations. The calculated angular dependences of intensities of both diffracted and transmitted X-rays correspond well to the experimentally obtained rocking curves and demonstrate their high sensitivity to the structural distortions in the channel. An unambiguous reconstruction of strain and structural distortions in the Si(Al) channel using the Laue diffraction data requires further development of the theoretical model.

Hydration Phenomena in a Concentrated Aqueous Solution of Ce(NO3)3. X-ray Diffraction and Raman Spectroscopy

1983 ◽  
Vol 38 (5) ◽  
pp. 533-539 ◽  
Author(s):  
R. Caminiti ◽  
P. Cucca ◽  
A. D′Andrea
Keyword(s):  
Experimental Data ◽  
Aqueous Solution ◽  
Raman Spectroscopy ◽  
Correlation Function ◽  
Hydration Shell ◽  
X Rays ◽  
X Ray Diffraction ◽  
X Ray ◽  
Experimental Correlation ◽  
Good Agreement

The scattering of X-rays from a concentrated Ce(NO3)3 aqueous solution has been measured and analyzed. The experimental correlation function appears to be mainly characterized by the hydration of the cation: peaks at about 2.55 and 4.65 Å. Good agreement with experimental data is achieved through a model in which the Ce(III) ions have a first and a second hydration shell and also the nitrate group is considered hydrated. Complex formation between cation and anion is confirmed by using Raman spectroscopy.

Book Reviews: The gentle pioneer

1996 ◽  
Vol 50 (2) ◽  
pp. 263-264
Keyword(s):  
Modern Science ◽  
Mathematical Physics ◽  
Dynamical Theory ◽  
X Rays ◽  
Experimental Demonstration ◽  
X Ray Diffraction ◽  
International Union ◽  
X Ray ◽  
Oxford University

P.P. Ewald and his Dynamical Theory of X-ray Diffraction . Edited by D.W.J. Cruickshank, H.J. Juretschke & N. Kato. International Union of Crystallography, Oxford University Press, 1992. Pp. x+161, £40.00. ISBN 0-19-855379-X Paul Ewald, who died in 1985 at the age of 97, was one of the greats of modern science. Born in Berlin into a comfortable middle-class academic family, he developed a passion for mathematical physics. When Sommerfeld presented him with a list of possible topics for his Doctoral Thesis he chose one related to crystal optics. This work, presented in 1912, could be applied to the behaviour of X-rays in crystals and it is suggested that it was a conversation between von Laue and Ewald early in 1912 that gave von Laue the idea for his famous experimental demonstration of X-ray diffraction.

scholarly journals Experimentally obtained and computer-simulated X-ray asymmetric eight-beam pinhole topographs for a silicon crystal

2019 ◽  
Vol 75 (3) ◽  
pp. 474-482 ◽  
Author(s):  
Kouhei Okitsu ◽  
Yasuhiko Imai ◽  
Yoshitaka Yoda ◽  
Yoshinori Ueji
Keyword(s):  
Eigenvalue Problem ◽  
Fourier Transformation ◽  
Silicon Crystal ◽  
Fast Fourier Transformation ◽  
X Rays ◽  
Acta Cryst ◽  
X Ray ◽  
Simulated Images ◽  
Laue Geometry ◽  
Good Agreement

In this study, experimentally obtained eight-beam pinhole topographs for a silicon crystal using synchrotron X-rays were compared with computer-simulated images, and were found to be in good agreement. The experiment was performed with an asymmetric all-Laue geometry. However, the X-rays exited from both the bottom and side surfaces of the crystal. The simulations were performed using two different approaches: one was the integration of the n-beam Takagi–Taupin equation, and the second was the fast Fourier transformation of the X-ray amplitudes obtained by solving the eigenvalue problem of the n-beam Ewald–Laue theory as reported by Kohn & Khikhlukha [Acta Cryst. (2016), A72, 349–356] and Kohn [Acta Cryst. (2017), A73, 30–38].

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