Anisotropic atomic structure in a homogeneously deformed metallic glass

2007 ◽  
Vol 22 (2) ◽  
pp. 382-388 ◽  
Author(s):  
M.J. Kramer ◽  
R.T. Ott ◽  
D.J. Sordelet
Keyword(s):  
Distribution Function ◽  
Metallic Glass ◽  
Atomic Structure ◽  
Pair Distribution Function ◽  
High Energy ◽  
Tensile Creep ◽  
Uniaxial Tensile ◽  
X Ray Diffraction ◽  
Orientation Anisotropy ◽  
Length Changes

The anisotropic atomic structure in a Zr41.2Ti13.8Cu12.5Ni10Be22.5 metallic glass strained during uniaxial tensile creep at 598 K was studied at room temperature using high-energy x-ray diffraction. Changes in the atomic structure were examined by comparing the total scattering function [S(Q)] and the reduced pair distribution function [G(r)] of the creep to that of a companion specimen subjected to the same heat treatment only. Two-dimensional maps of the ΔS(Q) and its Fourier transformation demonstrate the distribution in the bond orientation anisotropy increases with increasing total strain. A fit of the reduced pair distribution function using a simplified two-component model suggests that the bond length changes in the deformed creep samples are not uniform.

In-situ Pair Distribution Function Study of the Growth of Supported Platinum Particles in Zeolite X

2014 ◽  
Vol 1712 ◽  
Author(s):  
Liliana M. Gámez ◽  
Oscar Resto ◽  
Maria M. Martinez-Inesta
Keyword(s):  
Distribution Function ◽  
Pair Distribution Function ◽  
High Energy ◽  
X Ray Diffraction ◽  
Zeolite X ◽  
Time Resolved ◽  
Supported Platinum ◽  
Platinum Particles ◽  
Dehydrogenation Reactions

ABSTRACTPlatinum particles supported in zeolites are used as catalysts for hydrogenation/ dehydrogenation reactions. In this study in situ high energy synchrotron X-ray diffraction was used to study the Pt particle formation under calcination and reduction conditions using time resolved pair distribution function (PDF). Because these particles grow inside the pores of zeolite X, PDF is able to give insight to unique information at the short and medium interatomic distance range that cannot be readily obtained with other techniques. Among the information obtained are the Pt atom interactions during calcination and the evolvement of the Pt particle sizes and average Pt-Pt distances during reduction.

Liquid Atomic Structure and Viscosity of Al-Si Alloys with and without Sr

2011 ◽  
Vol 690 ◽  
pp. 222-225 ◽  
Author(s):  
Manickaraj Jeyakumar ◽  
Srirangam VS Prakash ◽  
Sumanth Shankar
Keyword(s):  
Distribution Function ◽  
Atomic Structure ◽  
Pair Distribution Function ◽  
Liquid Structure ◽  
High Energy ◽  
Beam Source ◽  
X Ray ◽  
Structure Information ◽  
Synchrotron Beam ◽  
Semi Empirical

The liquid structure of Al-Si hypoeutectic binary alloys with and without the addition of 0.04 wt.% Sr was characterized by diffraction experiments using a high energy X-Ray (Synchrotron) beam source. The diffraction data for all the alloys were obtained at various melt temperatures. Reverse Monte Carlo (RMC) analysis was carried out using the diffraction experimental data to quantify the partial pair distribution function (PPDF). Further, the partial pair distribution function and the liquid atomic structure information were used in a semi empirical model to evaluate the viscosity of these liquid alloys at various temperatures.

scholarly journals Crystal Structure of Moganite and Its Anisotropic Atomic Displacement Parameters Determined by Synchrotron X-ray Diffraction and X-ray/Neutron Pair Distribution Function Analyses

Minerals ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 272
Author(s):  
Seungyeol Lee ◽  
Huifang Xu ◽  
Hongwu Xu ◽  
Joerg Neuefeind
Keyword(s):  
Crystal Structure ◽  
Distribution Function ◽  
Single Crystal ◽  
Pair Distribution Function ◽  
Atomic Displacement ◽  
Single Crystal Xrd ◽  
X Ray Diffraction ◽  
X Ray ◽  
Neutron Pair ◽  
Atomic Displacement Parameters

The crystal structure of moganite from the Mogán formation on Gran Canaria has been re-investigated using high-resolution synchrotron X-ray diffraction (XRD) and X-ray/neutron pair distribution function (PDF) analyses. Our study for the first time reports the anisotropic atomic displacement parameters (ADPs) of a natural moganite. Rietveld analysis of synchrotron XRD data determined the crystal structure of moganite with the space group I2/a. The refined unit-cell parameters are a = 8.7363(8), b = 4.8688(5), c = 10.7203(9) Å, and β = 90.212(4)°. The ADPs of Si and O in moganite were obtained from X-ray and neutron PDF analyses. The shapes and orientations of the anisotropic ellipsoids determined from X-ray and neutron measurements are similar. The anisotropic ellipsoids for O extend along planes perpendicular to the Si-Si axis of corner-sharing SiO4 tetrahedra, suggesting precession-like movement. Neutron PDF result confirms the occurrence of OH over some of the tetrahedral sites. We postulate that moganite nanomineral is stable with respect to quartz in hypersaline water. The ADPs of moganite show a similar trend as those of quartz determined by single-crystal XRD. In short, the combined methods can provide high-quality structural parameters of moganite nanomineral, including its ADPs and extra OH position at the surface. This approach can be used as an alternative means for solving the structures of crystals that are not large enough for single-crystal XRD measurements, such as fine-grained and nanocrystalline minerals formed in various geological environments.

scholarly journals There's no place like real-space: elucidating size-dependent atomic structure of nanomaterials using pair distribution function analysis

2020 ◽  
Vol 2 (6) ◽  
pp. 2234-2254 ◽  
Author(s):  
Troels Lindahl Christiansen ◽  
Susan R. Cooper ◽  
Kirsten M. Ø. Jensen
Keyword(s):  
Distribution Function ◽  
Atomic Structure ◽  
Pair Distribution Function ◽  
Function Analysis ◽  
Real Space ◽  
Size Dependent ◽  
Structure Of Nanomaterials

We review the use of pair distribution function analysis for characterization of atomic structure in nanomaterials.

Temperature-dependent synchrotron X-ray diffraction, pair distribution function and susceptibility study on the layered compound CrTe3

2018 ◽  
Vol 233 (6) ◽  
pp. 361-370 ◽  
Author(s):  
Anna-Lena Hansen ◽  
Bastian Dietl ◽  
Martin Etter ◽  
Reinhard K. Kremer ◽  
David C. Johnson ◽  
...  
Keyword(s):  
Distribution Function ◽  
Pair Distribution Function ◽  
Exchange Interactions ◽  
Structural Distortion ◽  
Layered Compound ◽  
Minor Amount ◽  
Zero Field ◽  
X Ray Diffraction ◽  
X Ray ◽  
Anisotropic Expansion

Abstract Results of combined synchrotron X-ray diffraction and pair distribution function experiments performed on the layered compound CrTe3 provide evidence for a short range structural distortion of one of the two crystallographically independent CrTe6 octahedra. The distortion is caused by higher mobility of one crystallographically distinct Te ion, leading to an unusual large Debye Waller factor. In situ high temperature X-ray diffraction investigations show an initial crystallization of a minor amount of elemental Te followed by decomposition of CrTe3 into Cr5Te8 and Te. Additional experiments provide evidence that the Te impurity (<1%) cannot be avoided. Analyses of structural changes in the temperature range 100–754 K show a pronounced anisotropic expansion of the lattice parameters. The differing behavior of the crystal axes is explained on the basis of structural distortions of the Cr4Te16 structural building units. An abrupt distortion of the structure occurs at T≈250 K, which then remains nearly constant down to 100 K. The structural distortion affects the spin exchange interactions between Cr3+ cations. A significant splitting between field-cooled (fc) and zero-field-cooled (zfc) magnetic susceptibility is observed below about 200 K. Applying a small external magnetic field results in a substantial spontaneous magnetization, reminiscent of ferro- or ferrimagnet exchange interactions below ~240 K. A Debye temperature of ~150 K was extracted from heat capacity measurements.

Thermal stability of Mg3Sb1.475Bi0.475Te0.05 high performance n-type thermoelectric investigated through powder X-ray diffraction and pair distribution function analysis

2018 ◽  
Vol 6 (35) ◽  
pp. 17171-17176 ◽  
Author(s):  
Lasse Rabøl Jørgensen ◽  
Jiawei Zhang ◽  
Christian Bonar Zeuthen ◽  
Bo Brummerstedt Iversen
Keyword(s):  
Thermal Stability ◽  
Distribution Function ◽  
Pair Distribution Function ◽  
High Performance ◽  
Function Analysis ◽  
X Ray Diffraction ◽  
X Ray ◽  
Thermal Stability Of

The thermal stability of the high performance n-type Te-doped Mg3Sb1.5Bi0.5 system is investigated.

scholarly journals High-Energy X-ray Diffraction Study of Liquid Structure of Metallic Glass-Forming Zr70Cu30 Alloy

2005 ◽  
Vol 46 (12) ◽  
pp. 2799-2802 ◽  
Author(s):  
Akitoshi Mizuno ◽  
Seiichi Matsumura ◽  
Masahito Watanabe ◽  
Shinji Kohara ◽  
Masaki Takata
Keyword(s):  
Metallic Glass ◽  
Diffraction Study ◽  
Liquid Structure ◽  
High Energy ◽  
X Ray Diffraction ◽  
X Ray ◽  
Glass Forming
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