A uniaxial stress apparatus for single-crystal X-ray diffraction on a four-circle diffractometer: application to silicon and diamond

1982 ◽  
Vol 15 (2) ◽  
pp. 148-153 ◽  
Author(s):  
H. d'Armour ◽  
W. Denner ◽  
H. Schulz ◽  
M. Cardona
Keyword(s):  
Single Crystal ◽  
Internal Stress ◽  
Elastic Constants ◽  
Strain Gauge ◽  
Uniaxial Stress ◽  
Unexpected Result ◽  
X Ray Diffraction ◽  
X Ray ◽  
Lattice Constants ◽  
Stress Parameter

An apparatus for applying uniaxial stress to a single-crystal has been constructed. The stress is produced by turning a differential screw and is measured by a strain gauge. The device fits on a goniometer of a four-circle diffractometer and can rotate around all three axes of the goniometer without restrictions. The lattice constants of Si stressed along [111] were measured and compared with ultrasonically measured elastic constants. The internal stress parameter ξ was calculated from changes of the intensity of the 600 reflection: ξ = 0.74 ± 0.04, larger than the value generally accepted (ξ = 0.64 ± 0.04). The implications of this unexpected result are discussed.

Die Kristallstruktur von Tricarbonyl(2.6-di-tert-butyl-pyridin)chrom(0) bei 200 K / Crystal Structure of Tricarbonyl(2,6-di/tert-butyl-pyridine)chromium(0) at 200 K

1984 ◽  
Vol 39 (2) ◽  
pp. 213-216 ◽  
Author(s):  
Roland E. Schmidt ◽  
Werner Massa
Keyword(s):  
Crystal Structure ◽  
Single Crystal ◽  
Diffraction Data ◽  
Pyridine Ring ◽  
Chromium Atom ◽  
Methyl Groups ◽  
X Ray Diffraction ◽  
X Ray ◽  
Lattice Constants ◽  
Tert Butyl

Based on single crystal X-ray diffraction data the crystal structure of tricarbonyl(2,6-dwmbutyl- pyridine)chromium(0) has been determined at 200 K: space group P 21/n, Z = 4, lattice constants a = 680.6(5), b - 1383.3(10), c = 1763.0(16) pm, β = 96.53(8)°, refinement to Rw - 0.048 for 1672 independent reflections with FO > 2 σ. The chromium atom is η6π6- bonded to the essentially planar pyridine ring (Cr-C: 219-222 pm, Cr-N: 221 pm). The CO ligands show “eclipsed” orientation with respect to the 2, 4 and 6 position of the pyridine ring. Two CO groups fit into the gaps formed by two methyl groups of the tert-butyl substituents in 2 and 6 position, respectively. The results are discussed in context with related arene and λ3-phosphorine complexes

Residual Stress Measurement of Silicon Nitride and Silicon Carbide by X-Ray Diffraction Using Gaussian Curve Method

1988 ◽  
Vol 32 ◽  
pp. 459-469 ◽  
Author(s):  
Masanori Kurita ◽  
Ikuo Ihara ◽  
Nobuyuki Ono
Keyword(s):  
Residual Stress ◽  
Single Crystal ◽  
Elastic Constants ◽  
Stress Measurement ◽  
Polycrystalline Materials ◽  
X Ray Diffraction ◽  
X Ray ◽  
Small Areas ◽  
Curve Method ◽  
The Continuum

The residual stress induced by grinding or some thermal treatment has a large effect on the strength of ceramics. The X-ray technique can be used to nondestructively measure the residual stress in small areas on the surface of polycrystalline materials. The X-ray stress measurement is based on. the continuum mechanics for macroscopically isotropic polycrystalline materials. In this method, the stress value is calculated selectively from strains of a particular diffraction plane in the grains which are favorably oriented for the diffraction. In general, however, the elastic constants of a single crystal depend on the plane of the lattice, since a single crystal is anisotropic, The behavior of the deformation of individual crystals in the aggregate of polycrystalline materials under applied stress has not yet been solved successfully. Therefore, the stress constant and elastic constants for a particular diffracting plane should be determined experimentally in order to determine the residual stress accurately by X-ray diffraction.

Crystal Structure of ζ2' Martensite in Au-49.5at%Cd Alloy

1991 ◽  
Vol 246 ◽  
Author(s):  
Yutaka Emura ◽  
Takuya Ohba ◽  
Kazuhiro Otsuka
Keyword(s):  
Crystal Structure ◽  
Single Crystal ◽  
Crystal Lattice ◽  
Least Squares ◽  
Least Squares Method ◽  
Diffraction Method ◽  
X Ray Diffraction ◽  
Full Matrix ◽  
X Ray ◽  
Lattice Constants

AbstractCrystal structure of the ζ2' martensite in a Au-49.5at%Cd ally has been analyzed by the single crystal x-ray diffraction method. The crystal lattice was trigonal and the lattice constants were a:0.8095(3) and c=o.57940(6) nm. There were 18 atoms in a unit cell. The space group was P3, which was different from that previously determined by Vatanayon and Hehemann. The structure was refined by the full matrix least squares method to a final R factor of 7.8% and a weighted R factor of 4.1%.

Synthesis and Crystal Structure of K6Mo10O33

2007 ◽  
Vol 62 (1) ◽  
pp. 1-4 ◽  
Author(s):  
Nachiappan Arumugam ◽  
Eva-Maria Peters ◽  
Martin Jansen
Keyword(s):  
Crystal Structure ◽  
Solid State ◽  
Single Crystal ◽  
Molybdenum Oxide ◽  
Solid State Reaction ◽  
X Ray Diffraction ◽  
Synthesis And Crystal Structure ◽  
Space Group ◽  
X Ray ◽  
Lattice Constants

A new potassium molybdenum oxide, K6Mo10O33, was synthesized by solid state reaction from the appropriate quantities of pre-dried MoO3 and K2MoO4, fired at around 650 °C for 2 d. The structure has been solved by using single crystal X-ray diffraction. The compound adopts the space group P1, with the lattice constants a = 7.7100(5), b = 11.9659(8), c = 17.1321(12) A° , α = 86.42 (10), β = 77.18(10), γ = 74.14(10)°. The structure is built up of infinite chains of edge-sharing MoO6 octahedra and groups of four MoO6 octahedra forming Mo4O17 units. These sub-units are connected together by common vertices.

Crystal Structure of 3Ni(N03)2.16C6 H5NH2

1990 ◽  
Vol 45 (9-10) ◽  
pp. 1185-1189
Author(s):  
Michael Mahr ◽  
Inge Pabst ◽  
Konrad G. Weil
Keyword(s):  
Crystal Structure ◽  
Single Crystal ◽  
Ion Pairs ◽  
X Ray Diffraction ◽  
Nickel Ion ◽  
Ionic Solutions ◽  
Triclinic Space Group ◽  
X Ray ◽  
Lattice Constants ◽  
Contact Ion Pairs

Abstract The Compound 3Ni(NO3)2 -16C6H5NH2 was obtained by crystallization from solutions of Ni(NO3)2 • 6C6H5NH2 -2H2O in aniline. Its crystal structure was determined by single crystal X-ray diffraction. The crystals are triclinic, space group P1 with lattice constants a = 985.2 pm, ft = 1004.5 pm and c = 2514.3 pm, a = 96.34°, ß = 92.63° and y = 89.82°. The structure shows units of four aniline molecules and two slightly distorted nitrate ions in the coordination sphere of each nickel ion. These units are similar to contact ion pairs in concentrated ionic solutions.

Neutron and X-Ray Diffraction Study of Internal Stress in Thermomechanically Fatigued Single-Crystal Superalloy

2008 ◽  
Vol 39 (13) ◽  
pp. 3141-3148 ◽  
Author(s):  
Erdong Wu ◽  
Jinchao Li ◽  
Jun Zhang ◽  
Sucheng Wang ◽  
Guang Xie ◽  
...  
Keyword(s):  
Single Crystal ◽  
Diffraction Study ◽  
Internal Stress ◽  
Single Crystal Superalloy ◽  
X Ray Diffraction ◽  
X Ray

Electron Microscopy of Shock Loaded Polycrystalline Beryllium

1974 ◽  
Vol 32 ◽  
pp. 506-507 ◽  
Author(s):  
J. M. Galbraith ◽  
L. E. Murr ◽  
A. L. Stevens
Keyword(s):  
Electron Microscopy ◽  
Wave Propagation ◽  
Structural Change ◽  
Single Crystal ◽  
Diffraction Pattern ◽  
Shock Loading ◽  
Slip Systems ◽  
Compression Tests ◽  
X Ray Diffraction ◽  
X Ray

Uniaxial compression tests and hydrostatic tests at pressures up to 27 kbars have been performed to determine operating slip systems in single crystal and polycrystal1ine beryllium. A recent study has been made of wave propagation in single crystal beryllium by shock loading to selectively activate various slip systems, and this has been followed by a study of wave propagation and spallation in textured, polycrystal1ine beryllium. An alteration in the X-ray diffraction pattern has been noted after shock loading, but this alteration has not yet been correlated with any structural change occurring during shock loading of polycrystal1ine beryllium.This study is being conducted in an effort to characterize the effects of shock loading on textured, polycrystal1ine beryllium. Samples were fabricated from a billet of Kawecki-Berylco hot pressed HP-10 beryllium.

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