Crystallite Size Distribution of γ-ray Irradiated Polyethylenes as Revealed by Fourier Transformation of Line Profiles

1964 ◽  
Vol 3 (2) ◽  
pp. 112-116 ◽  
Author(s):  
Masatake Mori ◽  
Kenji Doi
Keyword(s):  
Crystallite Size ◽  
Size Distribution ◽  
Fourier Transformation ◽  
Line Profiles ◽  
Γ Ray

Crystallite size distribution and lattice distortions in polyethylene from analyses of Debye‐Scherrer line profiles

1973 ◽  
Vol 44 (5) ◽  
pp. 2211-2217 ◽  
Author(s):  
Osamu Yoda ◽  
Kenji Doi ◽  
Naoyuki Tamura ◽  
Isamu Kuriyama
Keyword(s):  
Crystallite Size ◽  
Size Distribution ◽  
Line Profiles ◽  
Lattice Distortions

Crystallite Size Broadening of Diffraction Line Profiles

2014 ◽  
pp. 15-48
Keyword(s):  
Crystallite Size ◽  
Size Distribution ◽  
Length Distribution ◽  
Finite Size ◽  
Distribution Functions ◽  
Diffraction Line ◽  
Line Profiles ◽  
Column Length ◽  
Line Shapes ◽  
Peak Broadening

In this chapter, the X-ray peak profile broadening caused by the finite size of scattering crystallites is studied in detail. According to Bertaut’s theorem, the line profile with the indices hkl is determined by the length distribution of columns building up the scattering crystallites normal to the hkl reflecting planes. The column length distribution determined from line profiles can be converted into crystallite size distribution. The effect of median and variance of crystallite size distribution on the shape of line profiles is also discussed. The line shapes for different crystallite size distribution functions (e.g. lognormal and York distributions) are given. It is shown that for spherical crystallites the peak broadening does not depend on the indices of reflections. The dependence of line profiles on the indices hkl is presented for various anisotropic shapes of crystallites.

scholarly journals X-ray diffraction study of crystallite size-distribution and strain in carbon blacks

2000 ◽  
Vol 661 ◽  
Author(s):  
T. Ungár ◽  
J. Gubicza ◽  
G. Ribárik ◽  
T. W. Zerda
Keyword(s):  
Crystallite Size ◽  
Size Distribution ◽  
Fourier Coefficients ◽  
Shape Anisotropy ◽  
X Ray Diffraction ◽  
Strain Anisotropy ◽  
X Ray ◽  
Carbon Blacks ◽  
Size Profile ◽  
Crystallite Shape

ABSTRACTThe crystallite size and size-distribution in carbon blacks in the presence of strain are determined by recently developed procedure of X-ray diffraction peak profile analysis. The Fourier coefficients of the measured physical profiles are fitted by Fourier coefficients of well established ab initio functions of size and strain peak profiles. Strain anisotropy is accounted for by expressing the mean square strain in terms of average dislocation contrast factors. Crystallite shape anisotropy is modelled by ellipsoids incorporated into the size profile function. To make the fitting procedure faster, the Fourier transform of the size profile is given as an analitical function. The method is applied to carbon blacks treated at different preassures and temperatures. The microstructure is characterised in terms of crystallite size distribution, dislocation density, and crystallite shape anisotropy.

Influence of Fuel in the Synthesis of ZnAl2O4 Catalytic Supports by Combustion Reaction

2010 ◽  
Vol 660-661 ◽  
pp. 52-57 ◽  
Author(s):  
Kaline Melo de Souto Viana ◽  
Bruno Brito Dantas ◽  
N.A.S. Nogueira ◽  
J.M. Sasaki ◽  
Normanda Lino de Freitas ◽  
...  
Keyword(s):  
Particle Size ◽  
Particle Size Distribution ◽  
Crystallite Size ◽  
Size Distribution ◽  
Spinel Structure ◽  
Morphological Characteristics ◽  
Combustion Reaction ◽  
Nanosized Particles ◽  
Catalytic Supports ◽  
Stoichiometric Proportion

The aim of this work is to evaluate the influence of fuel in the synthesis of ZnAl2O4 catalytic supports by combustion reaction. For this, it was used the fuels: urea, carbohidrazide, glycine and aniline. The total amount of reagents was calculated according to the theory of propellants and explosive using urea in the stoichiometric proportion (Φe = 1). The structural and morphological characteristics of the powders were evaluated by XRD, FTIR, TEM, SEM and particle size distribution. The results from XRD showed the formation of the normal cubic spinel structure. The powders presented nanosized particles with narrow agglomerates size distribution. The powders prepared with urea showed better value of surface area and smaller crystallite size.

scholarly journals Solving the γ-ray radiative transfer equation for supernovae

2019 ◽  
Vol 487 (1) ◽  
pp. 1218-1226 ◽  
Author(s):  
Kevin D Wilk ◽  
D John Hillier ◽  
Luc Dessart
Keyword(s):  
Radiative Transfer ◽  
Energy Deposition ◽  
Radiative Transfer Equation ◽  
Moving Frame ◽  
Synthetic Spectrum ◽  
Monte Carlo Code ◽  
Line Profiles ◽  
Large Expansion ◽  
Γ Rays ◽  
Γ Ray

ABSTRACT We present a new relativistic radiative transfer code for γ-rays of energy less than 5 MeV in supernova (SN) ejecta. This code computes the opacities, the prompt emissivity (i.e. decay), and the scattering emissivity, and solves for the intensity in the co-moving frame. Because of the large expansion velocities of SN ejecta, we ignore redistribution effects associated with thermal motions. The energy deposition is calculated from the energy removed from the radiation field by scattering or photoelectric absorption. This new code yields comparable results to an independent Monte Carlo code. However, both yield non-trivial differences with the results from a pure absorption treatment of γ-ray transport. A synthetic observer’s frame spectrum is also produced from the co-moving frame intensity. At early times when the optical depth to γ-rays is large, the synthetic spectrum shows asymmetric line profiles with redshifted absorption as seen in SN 2014J. This new code is integrated within cmfgen and allows for an accurate and fast computation of the decay energy deposition in SN ejecta.

New limit on the size distribution of γ-ray bursts

Nature ◽  
1976 ◽  
Vol 262 (5567) ◽  
pp. 370-371 ◽  
Author(s):  
J. CARTER ◽  
A. J. DEAN ◽  
R. K. MANCHADA ◽  
D. RAMSDEN
Keyword(s):  
Size Distribution ◽  
Γ Ray

Linienprofilanalyse von Röntgen-Weitwinkelreflexen mittels Fourier-Transformation zur Bestimmung von Mikrospannungen und parakristallinen Störungen / Analysis of X-Ray Line Profiles for Microstrains and Paracrystalline Distortions by Fourier Transformation

1974 ◽  
Vol 29 (8) ◽  
pp. 1152-1158 ◽  
Keyword(s):  
Gaussian Distribution ◽  
Fourier Transformation ◽  
The Other ◽  
Line Profiles ◽  
Linear Polyethylene ◽  
X Ray ◽  
Other Hand ◽  
Distortion Analysis ◽  
Diffraction Patterns

Many synthetic and biopolymers are paracrystalline. The same holds for some catalysts, graphites and semiconductors. This can be proved directly by diffraction patterns, the integral widths being proportional to (sin ϑ)2 for the higher orders of reflection of the same net plane. To test this, three orders of reflections must be observable. Warren, on the other hand, has shown that microstrains with a Gaussian distribution can directly be calculated from the line profiles of only two reflections by Fourier-Transformation. His method is expanded here to other types of microstrains and to paracrystalline distortions by carefully taking into account a termination effect. Examples are given for turbostratic graphite, linear polyethylene and annealed polybutene I. They demonstrate how useful this method is for distortion analysis.

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