A direct method for separating peak multiplet in x-Ray and gamma-ray spectra

1995 ◽  
Vol 46 (3) ◽  
pp. 181-184 ◽  
Author(s):  
S.A. Gerasimov
Keyword(s):  
Gamma Ray ◽  
Direct Method ◽  
X Ray ◽  
A Direct Method

A direct method of beam-height correction in small-angle X-ray scattering

1993 ◽  
Vol 26 (6) ◽  
pp. 787-794 ◽  
Author(s):  
M. A. Singh ◽  
S. S. Ghosh ◽  
R. F. Shannon
Keyword(s):  
Small Angle ◽  
Direct Method ◽  
Triangular Matrix ◽  
Random Errors ◽  
X Ray ◽  
X Ray Scattering ◽  
Beam Height ◽  
The Given ◽  
A Direct Method ◽  
Ray Scattering

A direct (i.e. noniterative) method for desmearing the beam-height effect in small-angle X-ray scattering is discussed. The method is applicable to rectangular collimation systems with arbitrary beam-height intensity profiles. The process involves the construction of an upper-triangular matrix of terms containing the resolution information. A straightforward back-substitution process can then be used to determine the ideal pinhole-collimated curve for any experimental curve obtained with the given resolution. The principal advantage of the method lies in its simplicity, which facilitates an examination of the propagation of random errors through the desmearing process. A comparison between the direct method and the iterative approach of Glatter [J. Appl. Cryst. (1974), 7, 147–153] is made to illustrate the efficiency of the technique.

Determination of the photoelectron emission probability with inclined X-ray Laue diffraction

1986 ◽  
Vol 42 (1) ◽  
pp. 24-29 ◽  
Author(s):  
A. M. Afanas'ev ◽  
R. M. Imamov ◽  
E. Kh. Mukhamedzhanov ◽  
A. N. Chuzo
Keyword(s):  
Angular Dependence ◽  
Direct Method ◽  
Simple Relation ◽  
Photoelectron Emission ◽  
Laue Diffraction ◽  
X Ray ◽  
Different Depths ◽  
First Time ◽  
A Direct Method

A simple relation has been established between the Fourier component of the probability density P(z) of photoelectron emission from different depths of a crystal and the angular dependence of the emission of photoelectrons formed in inclined X-ray Laue diffraction, which for the first time permitted the use of a direct method for the reconstruction of the P(z) function. Accurate measurements of the angular dependence of photoelectron emission were carried out on a silicon single crystal with diffraction of Cu Kα radiation for different energy ranges. Photoelectrons were recorded by a proportional gas counter specially designed for the energy analysis of photoelectrons under inclined Laue diffraction conditions. The laws predicted by the theory have been fully confirmed, and the corresponding P(z) functions have been obtained.

Double-Scanning Diffractometry in the Back-Reflection Region

1964 ◽  
Vol 8 ◽  
pp. 1-10 ◽  
Author(s):  
Hubert W. King ◽  
Carolyn M. Russell
Keyword(s):  
High Power ◽  
Entire Range ◽  
Direct Method ◽  
Lattice Parameter ◽  
Primary Beam ◽  
Double Scanning ◽  
X Ray ◽  
Standard Specimens ◽  
Scanning Range ◽  
A Direct Method

AbstractA scanning range over Bragg angles from −163 to +163° 2θ is obtained by combining a diffractometer capable of scanning both sides of the primary X-ray beam with a very short (3-in.) high-power focused X-ray tube. The ability to scan the included angle 4θ between respective diffraction profiles on either side of the primary beam over the entire range of Bragg angles, provides a direct method of eliminating errors caused by a displacement of the specimen surface from the axis of the goniometer. The method is demonstrated by determining the lattice parameters of standard specimens used in the I.U.Cr. Precision Lattice Parameter Project.

scholarly journals Crystal structure of a new HfO(OH)2 oxyhydroxide

2013 ◽  
Vol 28 (S2) ◽  
pp. S510-S518
Author(s):  
N.V. Tarakina ◽  
A.P. Tyutyunnik ◽  
Ya.V. Baklanova ◽  
L.G. Maksimova ◽  
T.A. Denisova ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Pair Distribution Function ◽  
Direct Method ◽  
X Ray ◽  
Ion Exchange Reaction ◽  
Atomic Pair Distribution Function ◽  
Profile Fitting ◽  
Atomic Pair ◽  
Full Profile ◽  
A Direct Method

The crystal structure of a new hafnium oxyhydroxide obtained by an ion-exchange reaction from a Li2HfO3 precursor has been solved by a direct method and refined using Rietveld full profile fitting based on X-ray powder diffraction data. HfO(ОН)2 crystallizes in a P21/c monoclinic unit cell (a = 5.5578(5) Å, b = 9.0701(10) Å, c = 5.7174(5) Å, β = 119.746(5)°); its structure can be described as a framework formed by edge-sharing HfO6 octahedra connected to each other via vertices. In addition, an analysis of the atomic pair distribution function obtained using synchrotron radiation was used to confirm the model and to describe fine-structure features.

Crystal Structure of an Ammonium Dithiocyanatocuprate(I) Complex with 18-Crown-6, [NH4(18-Crown-6){Cu(NCS)2}] Obtained from Zero Valent Metal

1997 ◽  
Vol 52 (11) ◽  
pp. 1311-1314 ◽  
Author(s):  
Julia A. Manskaya ◽  
Volodimir N. Kokozay ◽  
Konstantin V. Domasevitch
Keyword(s):  
Crystal Structure ◽  
Direct Method ◽  
Orthorhombic Space Group ◽  
Space Group ◽  
One Dimensional ◽  
X Ray ◽  
X Ray Crystallography ◽  
A Direct Method

The new macrocyclic dithiocyanatocuprate(I) complex [NH4(18-crown-6){Cu(NCS)2}] has been prepared using a direct method of interaction and characterized by X-ray crystallography (orthorhombic, space group Cmc21, with a = 12.453(2), b = 21.650(4), c = 8.151(2) Å, V = 2197.6(8) Å3, Z = 4 , R1 (F) = 0.054; wR2(F2) = 0.141 for 972 unique reflections with I > 2σ(I) and R1(F) = 0.082; w/?2(F2) = 0.210 for all 1098 unique reflections). The lattice comprises complex cations [NH4(18-crown-6)]+ and infinite polymeric anions [Cu(NCS)2]- of a one-dimensional zig-zag structure. The copper atoms adopt three-fold coordination [CuN2S] (Cu-N 1,89( 1), 1,90( 1) Å; Cu-S 2.278(4) Å).

Determination of depth profiles from X-ray diffraction data

1993 ◽  
Vol 8 (2) ◽  
pp. 122-126 ◽  
Author(s):  
Paul Predecki
Keyword(s):  
Diffraction Data ◽  
Direct Method ◽  
Sample Surface ◽  
Data Sets ◽  
X Ray Diffraction ◽  
Data Set ◽  
X Ray ◽  
Depth Profiles ◽  
A Direct Method

A direct method is described for determining depth profiles (z-profiles) of diffraction data from experimentally determined τ-profiles, where z is the depth beneath the sample surface and τ is the 1/e penetration depth of the X-ray beam. With certain assumptions, the relation between these two profile functions can be expressed in the form of a Laplace transform. The criteria for fitting experimental τ-data to functions which can be utilized by the method are described. The method was applied to two τ-data sets taken from the literature: (1) of residual strain in an A1 thin film and (2) of residual stress in a surface ground A12O3/5vol% TiC composite. For each data set, it was found that the z-profiles obtained were of two types: oscillatory and nonoscillatory. The nonoscillatory profiles appeared to be qualitatively consistent for a given data set. The oscillatory profiles were considered to be not physically realistic. For the data sets considered, the nonoscillatory z-profiles were found to lie consistently above the corresponding τ-profiles, and to approach the τ-profiles at large z, as expected from the relation between the two.

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