Non-Parametric Comparison of Crystallographic Orientation Distributions

2021 ◽  
Vol 1016 ◽  
pp. 1258-1263
Author(s):  
Helmut Schaeben
Keyword(s):  
Density Function ◽  
Crystallographic Orientation ◽  
Orientation Distribution ◽  
Sequential Design ◽  
One Dimensional ◽  
X Ray ◽  
Design For X ◽  
Orientation Density ◽  
Orientation Distributions ◽  
Definition Of

Revisiting a spiral design for X-ray pole figure measurementsand a symbolic definition of a cumulative crystallographic orientation distributiona one-dimensional deterministic approximately uniform sequential design is appliedto evaluate and cumulate a given orientation density function resulting in a properly definedcumulative crystallographic orientation distribution.It provides a complementary means to compare distributionsin terms of graphs and the Kolomogorov-Smirnov distance.

Formation of Cr-rich Nano-clusters and Columns in (Zn,Cr)Te Grown by MBE

2009 ◽  
Vol 1183 ◽  
Author(s):  
Yôtarõ Nishio ◽  
Kôichirô Ishikawa ◽  
Shinji Kuroda ◽  
Masanori Mitome ◽  
Yoshio Bando
Keyword(s):  
Magnetic Properties ◽  
Substrate Temperature ◽  
Crystallographic Orientation ◽  
Vertical Direction ◽  
Growth Conditions ◽  
Chemical Analyses ◽  
Mbe Growth ◽  
One Dimensional ◽  
X Ray ◽  
Cr Content

AbstractThe correlation between the Cr aggregation and magnetic properties are investigated for the series of Zn1-xCrxTe films grown by MBE with a systematic variation of growth conditions. Structural and chemical analyses using TEM and energy-dispersive X-ray spectroscopy (EDS) reveal that the crystallinity and the Cr distribution change significantly with the substrate temperature during the MBE growth. For a relatively low average Cr content x ≅ 0.05, it is found that the crystal quality is improved with the increase of the substrate temperature. For a higher average Cr content x ≅ 0.2, the shape of Cr-rich regions is transformed from isolated clusters into one-dimensional nanocolumns with the increase of the substrate temperature. The direction of the nanocolumn formation changes depending on the crystallographic orientation of the grown films. In the magnetization measurements, anisotropic magnetic properties are observed in the films in which Cr-rich nanocolumns are formed in the vertical direction, depending on the relation between the direction of the nanocolumns and the applied magnetic fields.

Orientation density function-controlled pole probability density function measurements: automated adaptive control of texture goniometers

2007 ◽  
Vol 40 (3) ◽  
pp. 570-579 ◽  
Author(s):  
Helmut Schaeben ◽  
Ralf Hielscher ◽  
Jean-Jacques Fundenberger ◽  
Daniel Potts ◽  
Jürgen Prestin
Keyword(s):  
Mathematical Method ◽  
Adaptive Control ◽  
Probability Density Function ◽  
Density Function ◽  
Crystallographic Orientation ◽  
Uniform Grid ◽  
Successive Refinement ◽  
Orientation Density ◽  
Refined Grid ◽  
Fast Inversion

A novel control of a texture goniometer, which depends on the texture being measured itself, is suggested. In particular, it is suggested that the obsolete control with constant step sizes in both angles is replaced by an adaptive successive refinement of an initial coarse uniform grid to a locally refined grid, where the progressive refinement corresponds to the pattern of preferred crystallographic orientation. The prerequisites of this automated adaptive control is the fast inversion of pole intensities to orientation probabilities in the course of the measurements, and a mathematical method of inversion that does not require a raster of constant step sizes and applies to sharp textures.

Effect of Creep Deformation on the Crystallographic Orientation Distribution in Ni Base Superalloy

2007 ◽  
Vol 26-28 ◽  
pp. 213-216 ◽  
Author(s):  
Toru Inoue ◽  
Katsushi Tanaka ◽  
Hiroki Adachi ◽  
Kyosuke Kishida ◽  
Haruyuki Inui
Keyword(s):  
Creep Deformation ◽  
Crystallographic Orientation ◽  
Orientation Distribution ◽  
Diffraction Peak ◽  
High Temperature Creep ◽  
Rocking Curve ◽  
Burgers Vector ◽  
X Ray ◽  
Creep Deformations ◽  
Base Superalloy

The crystallographic orientation distribution, and its change as a function of creep deformation in Ni-based single crystal superalloys have been investigated by X-ray diffractometry. The distribution of the crystallographic orientation has significantly broadened by creep deformations. Directional broadening of the distribution agrees with creep dislocations having the burgers vector of 1/2<101>. High temperature creep strain of superalloys can be estimated by a non-destractive test where the width of rocking curve of a diffraction peak is measured.

Effective aperture of X-ray compound refractive lenses

2017 ◽  
Vol 24 (3) ◽  
pp. 609-614 ◽  
Author(s):  
V. G. Kohn
Keyword(s):  
Integral Intensity ◽  
Two Dimensional ◽  
One Dimensional ◽  
X Ray ◽  
The Real ◽  
A Value ◽  
Effective Aperture ◽  
The One ◽  
Definition Of ◽  
Focusing Properties

A new definition of the effective aperture of the X-ray compound refractive lens (CRL) is proposed. Both linear (one-dimensional) and circular (two-dimensional) CRLs are considered. It is shown that for a strongly absorbing CRL the real aperture does not influence the focusing properties and the effective aperture is determined by absorption. However, there are three ways to determine the effective aperture in terms of transparent CRLs. In the papers by Kohn [(2002). JETP Lett. 76, 600–603; (2003). J. Exp. Theor. Phys. 97, 204–215; (2009). J. Surface Investig. 3, 358–364; (2012). J. Synchrotron Rad. 19, 84–92; Kohn et al. (2003). Opt. Commun. 216, 247–260; (2003). J. Phys. IV Fr, 104, 217–220], the FWHM of the X-ray beam intensity just behind the CRL was used. In the papers by Lengeler et al. [(1999). J. Synchrotron Rad. 6, 1153–1167; (1998). J. Appl. Phys. 84, 5855–5861], the maximum intensity value at the focus was used. Numerically, these two definitions differ by 50%. The new definition is based on the integral intensity of the beam behind the CRL over the real aperture. The integral intensity is the most physical value and is independent of distance. The new definition gives a value that is greater than that of the Kohn definition by 6% and less than that of the Lengeler definition by 41%. A new approximation for the aperture function of a two-dimensional CRL is proposed which allows one to calculate the two-dimensional CRL through the one-dimensional CRL and to obtain an analytical solution for a complex system of many CRLs.

scholarly journals Anisotropic resistivity tensor of melt-cast Bi2212 superconductors from QTA

2014 ◽  
Vol 70 (a1) ◽  
pp. C726-C726
Author(s):  
Aline Dellicour ◽  
Alain Pautrat ◽  
Bénédicte Vertruyen ◽  
Mark Rikel ◽  
Luca Lutterotti ◽  
...  
Keyword(s):  
Geometric Mean ◽  
Orientation Distribution ◽  
Secondary Phases ◽  
X Ray Diffraction ◽  
Orthorhombic Space Group ◽  
Combined Analysis ◽  
X Ray ◽  
Resistivity Tensor ◽  
Resistivity Anisotropy ◽  
Orientation Distributions

Bi2Sr2CaCu2O8+δ HTSC superconductor is characterized by a very strong normal-state resistivity anisotropy, with ρc/ρab typically above 10E4. The aim of this study is to use Quantitative Texture Analysis from x-ray diffraction measurements to estimate the orientation effect on the anisotropic macroscopic resistivity in melt-cast bulk Bi2Sr2CaCu2O8+δ superconductors. Our approach uses the geometric mean [1] of the single crystal resistivity tensor weighted by the Orientation Distribution Function (ODF) to quantitatively estimate the macroscopic resistivity tensor of the samples. The ODF is obtained from x-ray Combined Analysis [2], using the E-WIMV algorithm of the MAUD software. The GMA applies to the rank-two resistivity tensor of the orthorhombic space group considered tetragonal due to the small difference of a- and b-axes of the phase, with only two independent tensor components. We relate a relatively good agreement between measured and calculated macroscopic anisotropic resistivity ratios. Even with ρc/ρab between 10E4 and 10E5 for Bi2212 at room temperature in single crystals [3], we experiment macroscopic ratio in our bulk samples of around only 2. This small ratio is explained by the weak planar- or fiber-like (Figure) texture achieved in the melt-cast samples, characterized by maxima of orientation distributions not larger than 10 mrd. Calculated resistivities, based on homogeneous crystallites, perfect grain boundaries and no secondary phases, are 10 times larger than the observed ones. This suggests that the observed minor phases positively affect conductive pathways between grains. Calculated and measured anisotropic resistive ratios are coherent with one another, and Combined Analysis gives good predictions of these former.

The Broadening of Crystallographic Orientation Distribution in Crept Ni-base Superalloys

2006 ◽  
Vol 980 ◽  
Author(s):  
Toru Inoue ◽  
Katsushi Tanaka ◽  
Hiroki Adachi ◽  
Kyosuke Kishida ◽  
Haruyuki Inui
Keyword(s):  
Slip System ◽  
Single Crystal ◽  
Creep Strain ◽  
Crystallographic Orientation ◽  
Orientation Distribution ◽  
Diffraction Peak ◽  
Rocking Curve ◽  
X Ray ◽  
Elastic Plastic ◽  
Creep Deformations

AbstractThe crystallographic orientation distribution, and its change accompanied with tilting γ/γ boundaries in Ni-based single crystal superalloys have been investigated by a theoretical elastic-plastic calculation, X-ray diffractometry and SEM-EBSD analysis. The distribution of the crystallographic orientation has significantly broadened by creep deformations. The broadening can be explained by an unbalance of the amount of creep dislocations of each slip system, which agrees with the result of elastic-plastic calculations. Creep strain of superalloys crept at a condition forming the raft structure can be estimated by the measurement of the width of rocking curve of a diffraction peak.

The measurement of orientation distribution and its application to quantitative X-ray diffraction analysis

Clay Minerals ◽  
1966 ◽  
Vol 6 (3) ◽  
pp. 127-142 ◽  
Author(s):  
R.M. Taylor ◽  
K. Norrish
Keyword(s):  
Particle Morphology ◽  
Orientation Distribution ◽  
Particle Orientation ◽  
Small Specimen ◽  
X Ray Diffraction ◽  
X Ray ◽  
Naturally Occurring ◽  
Mathematical Relation ◽  
Degree Of Orientation ◽  
Orientation Distributions

AbstractUsing X-ray techniques, the orientation distributions of crystal planes in laboratory prepared and naturally occurring aggregates were measured. A small specimen was mounted on the axis of a goniometer and the diffracted intensity measured as the specimen was rotated. Mo radiation was used to reduce the absorption effects. A mathematical relation between the distribution of particles and the distribution of crystal planes was derived for platy and fibrous particles in flake-like and rod-shaped specimens.When diffracted intensities of the 001 reflection of several different kaolinites were corrected for the degree of orientation in the respective specimens, a constant value was obtained. This would enable quantitative diffraction analyses to be made without the large errors that can be introduced by orientation effects. The degree of particle orientation achieved appeared to be more dependent on particle morphology than on the method of sample preparation or formation.

The structure of amorphous and polycrystalline materials using energy-filtered RDF analysis

1992 ◽  
Vol 50 (2) ◽  
pp. 1190-1191
Author(s):  
David Cockayne ◽  
David McKenzie
Keyword(s):  
Electron Diffraction ◽  
Diffraction Pattern ◽  
Density Function ◽  
Electron Diffraction Pattern ◽  
Polycrystalline Materials ◽  
Nearest Neighbour ◽  
X Ray ◽  
Selected Area Electron Diffraction ◽  
Reduced Density ◽  
System F

The technique of Electron Reduced Density Function (RDF) analysis has ben developed into a rapid analytical tool for the analysis of small volumes of amorphous or polycrystalline materials. The energy filtered electron diffraction pattern is collected to high scattering angles (currendy to s = 2 sinθ/λ = 6.5 Å-1) by scanning the selected area electron diffraction pattern across the entrance aperture to a GATAN parallel energy loss spectrometer. The diffraction pattern is then converted to a reduced density function, G(r), using mathematical procedures equivalent to those used in X-ray and neutron diffraction studies.Nearest neighbour distances accurate to 0.01 Å are obtained routinely, and bond distortions of molecules can be determined from the ratio of first to second nearest neighbour distances. The accuracy of coordination number determinations from polycrystalline monatomic materials (eg Pt) is high (5%). In amorphous systems (eg carbon, silicon) it is reasonable (10%), but in multi-element systems there are a number of problems to be overcome; to reduce the diffraction pattern to G(r), the approximation must be made that for all elements i,j in the system, fj(s) = Kji fi,(s) where Kji is independent of s.

X-ray microprobe for materials science

1994 ◽  
Vol 52 ◽  
pp. 56-57
Author(s):  
G.E. Ice
Keyword(s):  
Crystallographic Orientation ◽  
Local Structure ◽  
Materials Science ◽  
Chemical Information ◽  
X Ray Diffraction ◽  
Ray Optics ◽  
X Ray ◽  
Novel Materials ◽  
New Information ◽  
Elemental Sensitivity

The increasing availability of synchrotron x-ray sources has stimulated the development of advanced hard x-ray (E≥5 keV) microprobes. With new x-ray optics these microprobes can achieve micron and submicron spatial resolutions. The inherent elemental and crystallographic sensitivity of an x-ray microprobe and its inherently nondestructive and penetrating nature will have important applications to materials science. For example, x-ray fluorescent microanalysis of materials can reveal elemental distributions with greater sensitivity than alternative nondestructive probes. In materials, segregation and nonuniform distributions are the rule rather than the exception. Common interfaces to whichsegregation occurs are surfaces, grain and precipitate boundaries, dislocations, and surfaces formed by defects such as vacancy and interstitial configurations. In addition to chemical information, an x-ray diffraction microprobe can reveal the local structure of a material by detecting its phase, crystallographic orientation and strain.Demonstration experiments have already exploited the penetrating nature of an x-ray microprobe and its inherent elemental sensitivity to provide new information about elemental distributions in novel materials.

Texture measurements in Al2O3 using BEKP

1994 ◽  
Vol 52 ◽  
pp. 608-609
Author(s):  
M. D. Vaudin ◽  
J. P. Cline
Keyword(s):  
Neutron Diffraction ◽  
Rapid Method ◽  
Crystallographic Orientation ◽  
Specimen Surface ◽  
X Ray Diffraction ◽  
Anisotropic Crystal ◽  
X Ray ◽  
Verification Method ◽  
Crystal Properties ◽  
Backscattered Electron

The study of preferred crystallographic orientation (texture) in ceramics is assuming greater importance as their anisotropic crystal properties are being used to advantage in an increasing number of applications. The quantification of texture by a reliable and rapid method is required. Analysis of backscattered electron Kikuchi patterns (BEKPs) can be used to provide the crystallographic orientation of as many grains as time and resources allow. The technique is relatively slow, particularly for noncubic materials, but the data are more accurate than any comparable technique when a sufficient number of grains are analyzed. Thus, BEKP is well-suited as a verification method for data obtained in faster ways, such as x-ray or neutron diffraction. We have compared texture data obtained using BEKP, x-ray diffraction and neutron diffraction. Alumina specimens displaying differing levels of axisymmetric (0001) texture normal to the specimen surface were investigated.BEKP patterns were obtained from about a hundred grains selected at random in each specimen.

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