Interpretation of x-ray and neutron diffraction patterns for liquid and amorphous yttrium and lanthanum aluminum oxides from computer simulation

2004 ◽  
Vol 69 (5) ◽  
Author(s):  
Mark Wilson ◽  
Paul F. McMillan
Keyword(s):  
Computer Simulation ◽  
Neutron Diffraction ◽  
Aluminum Oxides ◽  
X Ray ◽  
Diffraction Patterns

scholarly journals COMPUTER SIMULATION OF X-RAY DIFFRACTION PROFILES AND TEM DIFFRACTION PATTERNS ON ORDERING FOR Cu-4wt%Ti ALLOY

2000 ◽  
Vol 49 (5) ◽  
pp. 926
Author(s):  
WANG LIU-DING ◽  
CHEN CHANG-LE ◽  
LIU LIN ◽  
KANG MO-KUANG ◽  
JI BANG-JIE ◽  
...  
Keyword(s):  
Computer Simulation ◽  
Ti Alloy ◽  
X Ray Diffraction ◽  
X Ray ◽  
Diffraction Patterns

Phase Decomposition in Cu-Ti Metallic Glass

1983 ◽  
Vol 28 ◽  
Author(s):  
R. D. Shull ◽  
S. P. Singhal ◽  
B. Mozer ◽  
A. Maeland
Keyword(s):  
Neutron Diffraction ◽  
Metallic Glass ◽  
Melt Spinning ◽  
Large Angle ◽  
Amorphous State ◽  
Glass Ribbon ◽  
Amorphous Structure ◽  
Phase Decomposition ◽  
X Ray ◽  
Diffraction Patterns

ABSTRACTA metallic glass ribbon of Cu55Ti45 prepared by melt spinning was examined by x-ray, neutron, and electron diffraction, by small angle neutron diffraction (SANS), transmission electron microscopy (TEM), and by differential thermal analysis (DTA). In the liquid quenched condition large angle diffraction data (both x-ray and neutron) show the broad banded structure typical of the amorphous state. The SANS data, however, exhibit highly anisotropic patterns arising from the phase decomposition during solidification. Ribbons annealed below the glass transition temperature (Tg ) produced neutron diffraction patterns of materials with the same amorphous structure combined with a new short range order; and the SANS patterns retained the asymmetry of the as-quenched material. Ribbons annealed above the crystallization temperature (Tc) show both isotropic and anisotropic contributions to the SANS patterns. Formation of the equilibrium TiCu phase occurs directly from the metallic glass at Tc. The equilibrium Ti3Cu4 phase, however, forms from the TiCu phase at slightly higher temperatures.

Computer Simulation of Powder Patterns

1983 ◽  
Vol 27 ◽  
pp. 75-80
Author(s):  
W. Parrish ◽  
T. C. Huang ◽  
G. L. Ayers
Keyword(s):  
Computer Simulation ◽  
Powder Diffraction ◽  
Line Broadening ◽  
Instrument Function ◽  
X Ray ◽  
Profile Fitting ◽  
Fitting Algorithm ◽  
Diffraction Patterns

AbstractA method for computer simulation of X-ray powder diffraction patterns which are identical to those obtained experimentally is described. The calculated pattern is generated directly from the d's (or 2θs) and intensities of the phase(s) and is based on a profile fitting algorithm which uses the instrument function to form the profile shapes at all reflection angles. Examples of simulated patterns of mixtures, line broadening, linear and amorphous backgrounds, and counting noise are given.

Crystal structure of 0.96(Na0.5Bi0.5TiO3)–0.04(BaTiO3) from combined refinement of x-ray and neutron diffraction patterns

2012 ◽  
Vol 101 (15) ◽  
pp. 152906 ◽  
Author(s):  
T.-M. Usher ◽  
J. S. Forrester ◽  
C. R. dela Cruz ◽  
J. L. Jones
Keyword(s):  
Crystal Structure ◽  
Neutron Diffraction ◽  
X Ray ◽  
Diffraction Patterns

FINAX: a computer program for correcting diffraction angles, refining cell parameters and calculating powder patterns

1983 ◽  
Vol 16 (6) ◽  
pp. 651-653 ◽  
Author(s):  
E. R. Hovestreydt
Keyword(s):  
Neutron Diffraction ◽  
Computer Program ◽  
Powder Diffraction ◽  
Diffraction Data ◽  
Neutron Diffraction Data ◽  
X Ray ◽  
Cell Parameters ◽  
Theoretical Line ◽  
Diffraction Patterns ◽  
Line Positions

A computer program is described, whose purpose is the refinement of cell parameters from X-ray or neutron diffraction data. It is of particular use when working with powder diffraction patterns, as it has the possibility of (a) correcting the measured diffraction angles from reference reflections and of (b) calculating a theoretical powder diffractogram, including intensities. A minimum of crystallographic information has to be given and input is partially in free format. E.s.d.'s in cell parameters, as well as in the volume, are calculated. It handles α 1−α 2 splitting and calculates, apart from the theoretical line positions, also a more realistic position of where to expect a given reflection on the film.

Crystal structure of magnesium dichloride decahydrate determined by X-ray and neutron diffraction under high pressure

2015 ◽  
Vol 71 (1) ◽  
pp. 74-80 ◽  
Author(s):  
Kazuki Komatsu ◽  
Ayako Shinozaki ◽  
Shinichi Machida ◽  
Takuto Matsubayashi ◽  
Mao Watanabe ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Neutron Diffraction ◽  
Amorphous State ◽  
Water Molecules ◽  
X Ray ◽  
The Difference ◽  
Diffraction Patterns ◽  
Difference Fourier ◽  
First Time

Magnesium dichloride decahydrate (MgCl2·10H2O) and its deuterated counterpart (MgCl2·10D2O) are identified for the first time byin-situpowder synchrotron X-ray and spallation neutron diffraction. These substances are crystallized from a previously unidentified nanocrystalline compound, which originates from an amorphous state at low temperature. A combination of a recently developed autoindexing procedure and the charge-flipping method reveals that the crystal structure of MgCl2·10H2O consists of an ABCABC... sequence of Mg(H2O)6octahedra. The Cl−anions and remaining water molecules unconnected to the Mg2+cations bind the octahedra, similar to other water-rich magnesium dichloride hydrates. The D positions in MgCl2·10D2O, determined by the difference Fourier methods using the neutron powder diffraction patterns at 2.5 GPa, show the features such as bifurcated hydrogen bonds and tetrahedrally coordinated O atoms, which were not found in other forms of magnesium chloride hydrates.

Structural study of chlorine pentafluoride in the condensed phases

1978 ◽  
Vol 56 (10) ◽  
pp. 1353-1357 ◽  
Author(s):  
M. Drifford ◽  
R. Rousson ◽  
J. M. Weulersse
Keyword(s):  
Raman Spectrum ◽  
Neutron Diffraction ◽  
Raman Spectra ◽  
Vibrational Spectra ◽  
Room Temperature ◽  
Condensed Phases ◽  
Body Centered Cubic ◽  
X Ray ◽  
Solid Phases ◽  
Diffraction Patterns

Raman spectra of chlorine pentafluoride have been investigated in the condensed phases between room temperature and 4 K. X-Ray and neutron diffraction patterns were also recorded. The three solid phases previously described by nmr measurements have been characterised. Solid 1(161 K < T < 181 K) is body-centered cubic with a = 5.7 Å; its Raman spectrum is quite comparable with that of the liquid. Solid II (117 K < T < 161 K) is orthorhombic with a = 6.17 Å, b = 7.22 Å; c = 7.66 Å; according to the Raman spectra its structure seems to be similar to that of solid BrF5. The structure of solid III (T < 117 K) has not been determined; however, the vibrational spectra show that it is not very different from solid II.The analogy between the structures of the tri- and pentafluorides of chlorine and bromine is discussed.

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