X-ray Diffraction Investigations on Individual Grains in the Polycrystalline Ni-base Superalloy IN939 During Cyclice Loading I: X-ray Rocking Curve Broadening

1995 ◽  
Vol 86 (5) ◽  
pp. 371-377
Author(s):  
Rüdiger Dupke ◽  
Walter Reimers
Keyword(s):  
X Ray Diffraction ◽  
Rocking Curve ◽  
X Ray ◽  
Individual Grains ◽  
Base Superalloy

A common theory of line broadening and rocking curves

2015 ◽  
Vol 48 (2) ◽  
pp. 418-430 ◽  
Author(s):  
Gyula Zilahi ◽  
Tamás Ungár ◽  
Géza Tichy
Keyword(s):  
Rigid Body ◽  
Electron Backscatter Diffraction ◽  
Strain Tensor ◽  
Theoretical Description ◽  
Line Broadening ◽  
X Ray Diffraction ◽  
Rocking Curve ◽  
X Ray ◽  
Peak Broadening ◽  
Individual Grains

X-ray diffraction peak broadening is discussed in terms of line broadening and rocking-curve broadening in a novel theoretical description. The nonlocal strain tensor is factorized by using the method of polar decomposition instead of the more conventional separation into symmetrical and antisymmetrical components. A number of X-ray line-broadening and rocking-curve experiments on the same single crystals or individual grains in bulk polycrystals prove that plastic deformation produces strained subgrains mutually rotated by rigid-body rotations. The novel theoretical description appropriately accounts for the rigid-body rotation and strain at the same time and provides straightforward separation of the two effects of line and rocking-curve broadening in the radial and normal directions of the diffraction vector. The mathematical results are discussed in terms of experiments of X-ray diffraction, Laue asterism and electron backscatter diffraction. From the experimental results it is shown that the simultaneous evaluation of line and rocking-curve broadening provides qualitative information about the redundant and geometrically necessary character of dislocations, not available if only one or the other is accessible.

X-ray diffraction properties of curved crystal diffractors

1992 ◽  
Vol 50 (2) ◽  
pp. 1734-1735
Author(s):  
W. Z. Chang ◽  
D. B. Wittry
Keyword(s):  
Diffraction Theory ◽  
X Rays ◽  
Diffraction Image ◽  
X Ray Diffraction ◽  
Rocking Curve ◽  
X Ray ◽  
Bent Crystal ◽  
Diffraction Geometry ◽  
Crystal Parameter ◽  
Quantitative Procedure

Since Du Mond and Kirkpatrick first discussed the principle of a bent crystal spectrograph in 1930, curved single crystals have been widely utilized as spectrometric monochromators as well as diffractors for focusing x rays diverging from a point. Curved crystal diffraction theory predicts that the diffraction parameters - the rocking curve width w, and the peak reflection coefficient r of curved crystals will certainly deviate from those of their flat form. Due to a lack of curved crystal parameter data in current literature and the need for optimizing the choice of diffraction geometry and crystal materials for various applications, we have continued the investigation of our technique presented at the last conference. In the present abstract, we describe a more rigorous and quantitative procedure for measuring the parameters of curved crystals.The diffraction image of a singly bent crystal under study can be obtained by using the Johann geometry with an x-ray point source.

The Performance of Channel Cut Collimators for Precision X-Ray Diffraction Studies of Epitaxial Layers

1990 ◽  
Vol 208 ◽  
Author(s):  
Neil Loxley ◽  
D. Keith Bowen ◽  
Brian K. Tanner
Keyword(s):  
Grazing Incidence ◽  
Curve Analysis ◽  
Epitaxial Layers ◽  
Angular Divergence ◽  
X Ray Diffraction ◽  
Rocking Curve ◽  
Experimental Performance ◽  
Low Background ◽  
X Ray ◽  
Angle Scattering

ABSTRACTReplacement of the pinhole collimator on a double axis X-ray diffractometer with a device incorporating a channel-cut crystal permits the beam to be pre-conditioned in angular divergence. We examine the merits of such devices, known as channel-cut collimators (CCC's), of different materials and reflections. The experimental performance of InP 004 and Si 022 CCC's is presented.With a reference crystal on the first axis, set in the dispersive peometry with respect to the CCC, conditioning in wavelength spread is achieved. Dispersion broadening is effectively eliminated and no resetting of the reference crystal is required when changing specimen materials or reflections. The devices have extremely low background and reduced Bragg tails. Application of the 4-reflection CCC to rocking curve analysis of thin epitaxial layers, ultra-low angle scattering from biological systems, grazing incidence reflectometry and triple axis diffraction of semi-conductors is discussed.

scholarly journals Влияние толщины пленки Pt на изменение текстуры и доли кристаллической фазы при ее отжиге

2020 ◽  
Vol 90 (5) ◽  
pp. 795
Author(s):  
Р.В. Селюков ◽  
В.В. Наумов
Keyword(s):  
Volume Fraction ◽  
Curve Analysis ◽  
X Ray Diffraction ◽  
Rocking Curve ◽  
X Ray ◽  
Texture Parameters ◽  
Sputter Deposited ◽  
Pt Films ◽  
H 20

Textured Pt films with thickness h=20-80 nm were sputter deposited on oxidized c-Si (100) wafers and annealed in vacuum at 500°C/60 min. The thickness dependencies of the crystalline texture parameters and of the fraction of crystalline phase δ are obtained for as-deposited and annealed films using X-ray diffraction. The determination of δ in textured films is carried out by the new method based on rocking curve analysis. It is found that annealing leads to the texture improvement and to the increasing of δ for all h. The less h, the stronger effects of texture improvement and of δ increasing. These results are explained by the annealing-induced formation of large secondary grains whose volume fraction increases as h decreases. The inhomogeneity of the depth distributions of texture parameters and of δ are investigated for the as-deposited Pt films.

Accurate Lattice Constant and Mismatch Measurements of SiC Heterostructures by X-Ray Multiple-Order Reflections

2002 ◽  
Vol 742 ◽  
Author(s):  
XianRong Huang ◽  
Michael Dudley ◽  
Philip G. Neudeck ◽  
J. Anthony Powell
Keyword(s):  
Lattice Mismatch ◽  
Strain Relaxation ◽  
Relaxation Mechanism ◽  
X Ray Diffraction ◽  
Crystalline Perfection ◽  
Coherent Interface ◽  
Rocking Curve ◽  
X Ray ◽  
Lattice Planes ◽  
Atomically Flat

ABSTRACTHigh-resolution X-ray diffraction (HRXRD) combined with other diffraction techniques is applied to characterize 3C SiC epilayers hoteroepitaxially grown on atomically flat mesas on 4H and 6H SiC substrates. Small-beam rocking curve scan and reciprocal mapping show extremely high crystalline perfection and homogeneity of the ideally grown 3C-SiC epilayers. Accurate lattice measurements based on X-ray multiple-order reflections reveal that: 1) no misorientation between the (0001) lattice planes across the 4H/3C or 6H/3C interface is detected, confirming the 2D nucleation mechanism of the 3C epilayer from a flat coherent interface; 2) in-plane substrate/epilayer lattice mismatch always exists, but the 3C epilayers do not correspond to a completely relaxed cubic structure, indicating that the epilayers are partially strained; 3) lattice mismatch varies for different regions, implying a complicated strain relaxation mechanism of 3C epilayers on various mesas.

Crystallinity of YBa2Cu3O7−x single crystals grown by the pulling method

1996 ◽  
Vol 11 (4) ◽  
pp. 804-812 ◽  
Author(s):  
Y. Namikawa ◽  
M. Egami ◽  
S. Koyama ◽  
Y. Shiohara ◽  
H. Kutami
Keyword(s):  
Single Crystal ◽  
Single Crystals ◽  
Growth Direction ◽  
Annealed Sample ◽  
Seed Crystal ◽  
X Ray Diffraction ◽  
Rocking Curve ◽  
X Ray ◽  
Crystal Seed ◽  
Better Than

Large YBa2Cu3O7−x (Y123) single crystals (larger than 13 mm cubed) have been grown along the c-axis reproducibly by the modified pulling method. The crystallinity of Y123 single crystal was investigated by x-ray diffraction and x-ray topography. Crystals grown from an MgO single crystal seed had some low angle subgrain boundaries which tilted 0.1–0.8° from each other. These grain boundaries originated from the seed crystal, and the subgrains were extended along the growth direction from the seed crystal. Y123 single crystals with no marked subgrains in the whole area were obtained by using Y123 single subgrain crystal seeds. FWHM of the x-ray rocking curve for the crystal so produced was about 0.14°, which was much better than the spectrum consisting of several separated peaks obtained from the previous crystals. Tc onset of the annealed sample was about 93.6 K, and the transition width was about 0.9 K. The low angle subgrain boundaries did not seem to be effective pinning centers for the magnetic flux.

Hot-mesh Chemical Vapor Deposition for 3C-SiC Growth on Si and SiO2

2005 ◽  
Vol 862 ◽  
Author(s):  
Kanji Yasui ◽  
Jyunpei Eto ◽  
Yuzuru Narita ◽  
Masasuke Takata ◽  
Tadashi Akahane
Keyword(s):  
Chemical Vapor Deposition ◽  
Vapor Deposition ◽  
Chemical Vapor ◽  
X Ray Diffraction ◽  
Rocking Curve ◽  
Mesh Structure ◽  
X Ray ◽  
Si Substrates ◽  
Substrate Temperatures ◽  
Sic Films

AbstractThe crystal growth of SiC films on (100) Si and thermally oxidized Si (SiO2/Si) substrates by hot-mesh chemical vapor deposition (HMCVD) using monomethylsilane as a source gas was investigated. A mesh structure of hot tungsten (W) wire was used as a catalyzer. At substrate temperatures above 750°C and at a mesh temperature of 1600°C, 3C-SiC crystal was epitaxially grown on (100) Si substrates. From the X-ray rocking curve spectra of the (311) peak, SiC was also epitaxially grown in the substrate plane. On the basis of the X-ray diffraction (XRD) measurements, on the other hand, the growth of (100)-oriented 3C-SiC films on SiO2/Si substrates was determined to be achieved at substrate temperatures of 750-800°C, while polycrystalline SiC films, at substrate temperatures above 850°C. From the dependence of growth rate on substrate temperature and W-mesh temperature, the growth mechanism of SiC crystal by HMCVD was discussed.

Sign in / Sign up

Export Citation Format

Share Document