scholarly journals Texture and Lamellae Distribution Functions in Lamellar Eutectics

1986 ◽  
Vol 6 (4) ◽  
pp. 265-287 ◽  
Author(s):  
H. J. Bunge
Keyword(s):  
Three Dimensional ◽  
Orientation Distribution ◽  
Distribution Functions ◽  
X Rays ◽  
Two Dimensional ◽  
Absorption Factor ◽  
X Ray Diffraction ◽  
Diffraction Vector ◽  
X Ray ◽  
Pole Figures

The crystallographic orientation distribution and the geometrical lamellae orientation distribution in lamellar eutectics are, in general, not independent of each other. The combined orientation-lamellae distribution function depends on five angular parameters. X-ray diffraction in such eutectics may exhibit an anisotropic macroscopic absorption factor if the penetration depth of the X-rays is large compared with their planar size. As a consequence, the reflected X-ray intensity may depend on a third angle γ, i.e. a rotation of the sample about the diffraction vector s additionally to the usual pole figure angles α, β which describe the orientation of the diffraction vector s with respect to the sample coordinate system. It is thus necessary to measure three-dimensional generalized pole figures instead of conventional two-dimensional ones.

Textures Applied to Mechanical Processing Technology Assessment in Ancient Bronze

2005 ◽  
Vol 495-497 ◽  
pp. 719-724
Author(s):  
R.E. Bolmaro ◽  
B. Molinas ◽  
E. Sentimenti ◽  
A.L. Fourty
Keyword(s):  
Orientation Distribution ◽  
Distribution Functions ◽  
Archaeological Sites ◽  
Mechanical Processing ◽  
Post Processing ◽  
X Ray Diffraction ◽  
Mechanical Process ◽  
X Ray ◽  
Pole Figures ◽  
Microscopic Inspection

Some ancient metallic art craft, utensils, silverware and weapons are externally undistinguishable from modern ones. Not only the general aspect and shape but also some uses have not changed through the ages. Moreover, when just some small pieces can be recovered from archaeological sites, the samples can not easily be ascribed to any known use and consequently identified. It is clear that mechanical processing has changed along history but frequently only a "microscopic" inspection can distinguish among different techniques. Some bronze samples have been collected from the Quarto d’Altino (Veneto) archaeological area in Italy (paleovenetian culture) and some model samples have been prepared by a modern artisan. The sample textures have been measured by X-ray Diffraction techniques. (111), (200) and (220) pole figures were used to calculate Orientation Distribution Functions and further recalculate pole figures and inverse pole figures. The results were compared with modern forging technology results. Textures are able to discern between hammering ancient techniques for sheet production and modern industrial rolling procedures. However, as it is demonstrated in the present work, forgery becomes difficult to detect if the goldsmith, properly warned, proceeds to erase the texture history with some hammering post-processing. The results of this contribution can offer to the archaeologists the opportunity to take into consideration the texture techniques in order to discuss the origin (culture) of the pieces and the characteristic mechanical process developed by the ancient artisan. Texture can also help the experts when discussing the originality of a certain piece keeping however in mind the cautions indicated in this publication.

scholarly journals Numerical Calculation of Anisotropic Absorption Factors for Lamellar Two-Phase Structures

1990 ◽  
Vol 12 (4) ◽  
pp. 199-217
Author(s):  
Y. S. Liu ◽  
H. J. Bunge
Keyword(s):  
Numerical Calculation ◽  
Sample Surface ◽  
X Rays ◽  
Absorption Factor ◽  
X Ray Diffraction ◽  
Diffraction Vector ◽  
Absorption Coefficients ◽  
Two Phase ◽  
X Ray ◽  
Phase Structures

X-ray diffraction in a lamellar two-phase material is considered. If the lamellae thicknesses are small compared with the penetration depth of the X-rays then the absorption factor depends on the whole path of incident and reflected beam in both phases. Particularly, it depends on a rotation γ about the diffraction vector s additional to the orientation (αβ) of this vector with respect to the sample. Numerical calculations of the absorption factor A(αβγ) have been carried out for different values of lamellae thicknesses D1D2, absorption coefficients μ1μ2 and lamellae orientations ωρ with respect to the sample surface.

X-Ray Diffraction Investigation of Electrochemically Deposited Copper

2004 ◽  
Vol 443-444 ◽  
pp. 201-204 ◽  
Author(s):  
Karen Pantleon ◽  
Jens Dahl Jensen ◽  
Marcel A.J. Somers
Keyword(s):  
Process Parameters ◽  
Orientation Distribution ◽  
Distribution Functions ◽  
Organic Additives ◽  
X Ray Diffraction ◽  
X Ray ◽  
Pole Figures ◽  
Electrochemically Deposited ◽  
Cu Interconnect

Copper layers were deposited from acidic electrolytes containing different amounts of organic additives, designed for the formation of Cu-interconnect structures. Amorphous Ni-P substrates allow to study the unbiased growth of the electrodeposits. The crystallographic texture was investigated by the determination of X-ray diffraction (XRD) pole figures and the calculation of the orientation distribution functions. XRD results are discussed in relation to the morphologies of the electrodeposits as investigated with light optical microscopy and correlated with the process parameters during electrodeposition.

scholarly journals Low-Zpolymer sample supports for fixed-target serial femtosecond X-ray crystallography

2015 ◽  
Vol 48 (4) ◽  
pp. 1072-1079 ◽  
Author(s):  
Geoffrey K. Feld ◽  
Michael Heymann ◽  
W. Henry Benner ◽  
Tommaso Pardini ◽  
Ching-Ju Tsai ◽  
...  
Keyword(s):  
Protective Antigen ◽  
Three Dimensional ◽  
Two Dimensional ◽  
X Ray Diffraction ◽  
Fixed Target ◽  
X Ray ◽  
X Ray Crystallography ◽  
Transmission Electron ◽  
Linac Coherent Light Source ◽  
Efficient Alternative

X-ray free-electron lasers (XFELs) offer a new avenue to the structural probing of complex materials, including biomolecules. Delivery of precious sample to the XFEL beam is a key consideration, as the sample of interest must be serially replaced after each destructive pulse. The fixed-target approach to sample delivery involves depositing samples on a thin-film support and subsequent serial introductionviaa translating stage. Some classes of biological materials, including two-dimensional protein crystals, must be introduced on fixed-target supports, as they require a flat surface to prevent sample wrinkling. A series of wafer and transmission electron microscopy (TEM)-style grid supports constructed of low-Zplastic have been custom-designed and produced. Aluminium TEM grid holders were engineered, capable of delivering up to 20 different conventional or plastic TEM grids using fixed-target stages available at the Linac Coherent Light Source (LCLS). As proof-of-principle, X-ray diffraction has been demonstrated from two-dimensional crystals of bacteriorhodopsin and three-dimensional crystals of anthrax toxin protective antigen mounted on these supports at the LCLS. The benefits and limitations of these low-Zfixed-target supports are discussed; it is the authors' belief that they represent a viable and efficient alternative to previously reported fixed-target supports for conducting diffraction studies with XFELs.

Two new CdII MOFs of 1,4-bis(1H-benzimidazol-1-yl)butane and flexible dicarboxylate ligands: luminescence sensing towards Fe3+

2020 ◽  
Vol 76 (11) ◽  
pp. 1024-1033
Author(s):  
Fang-Hua Zhao ◽  
Shi-Yao Li ◽  
Wen-Yu Guo ◽  
Zi-Hao Zhao ◽  
Xiao-Wen Guo ◽  
...  
Keyword(s):  
Aqueous Solution ◽  
Solid State ◽  
Hydrogen Bonds ◽  
Layer Structure ◽  
Three Dimensional ◽  
Supramolecular Network ◽  
Two Dimensional ◽  
X Ray Diffraction ◽  
X Ray ◽  
Vis Spectroscopy

Two new CdII MOFs, namely, two-dimensional (2D) poly[[[μ2-1,4-bis(1H-benzimidazol-1-yl)butane](μ2-heptanedioato)cadmium(II)] tetrahydrate], {[Cd(C7H10O4)(C18H18N4)]·4H2O} n or {[Cd(Pim)(bbimb)]·4H2O} n (1), and 2D poly[diaqua[μ2-1,4-bis(1H-benzimidazol-1-yl)butane](μ4-decanedioato)(μ2-decanedioato)dicadmium(II)], [Cd2(C10H16O4)2(C18H18N4)(H2O)2] n or [Cd(Seb)(bbimb)0.5(H2O)] n (2), have been synthesized hydrothermally based on the 1,4-bis(1H-benzimidazol-1-yl)butane (bbimb) and pimelate (Pim2−, heptanedioate) or sebacate (Seb2−, decanedioate) ligands. Both MOFs were structurally characterized by single-crystal X-ray diffraction. In 1, the CdII centres are connected by bbimb and Pim2− ligands to generate a 2D sql layer structure with an octameric (H2O)8 water cluster. The 2D layers are further connected by O—H...O hydrogen bonds, resulting in a three-dimensional (3D) supramolecular structure. In 2, the CdII centres are coordinated by Seb2− ligands to form binuclear Cd2 units which are linked by bbimb and Seb2− ligands into a 2D hxl layer. The 2D layers are further connected by O—H...O hydrogen bonds, leading to an 8-connected 3D hex supramolecular network. IR and UV–Vis spectroscopy, thermogravimetric analysis and solid-state photoluminescence analysis were carried out on both MOFs. Luminescence sensing experiments reveal that both MOFs have good selective sensing towards Fe3+ in aqueous solution.

High Resolution Synchrotron X-Ray Diffraction Tomography Of Large-Grained Samples

1996 ◽  
Vol 437 ◽  
Author(s):  
D.P. Piotrowski ◽  
S.R. Stock ◽  
A. Guvenilir ◽  
J.D. Haase ◽  
Z.U. Rek
Keyword(s):  
Spatial Distribution ◽  
High Resolution ◽  
Three Dimensional ◽  
Polycrystalline Materials ◽  
Diffraction Tomography ◽  
Two Dimensional ◽  
X Ray Diffraction ◽  
Image Storage ◽  
X Ray ◽  
Dimensional Distribution

AbstractIn order to understand the macroscopic response of polycrystalline structural materials to loading, it is frequently essential to know the spatial distribution of strain as well as the variation of micro-texture on the scale of 100 μm. The methods must be nondestructive, however, if the three-dimensional evolution of strain is to be studied. This paper describes an approach to high resolution synchrotron x-ray diffraction tomography of polycrystalline materials. Results from model samples of randomly-packed, millimeter-sized pieces of Si wafers and of similarly sized single-crystal Al blocks have been obtained which indicate that polychromatic beams collimated to 30 μm diameter can be used to determine the depth of diffracting volume elements within ± 70 μm. The variation in the two-dimensional distribution of diffracted intensity with changing sample to detector separation is recorded on image storage plates and used to infer the depth of diffracting volume elements.

Poly[[μ-(1-azaniumylethane-1,1-diyl)bis(hydrogen phosphonato)]sodium]: a powder X-ray diffraction study

2013 ◽  
Vol 69 (8) ◽  
pp. 815-818 ◽  
Author(s):  
Mwaffak Rukiah ◽  
Thaer Assaad
Keyword(s):  
Hydrogen Bonding ◽  
Rietveld Method ◽  
Three Dimensional ◽  
Coordination Geometry ◽  
Two Dimensional ◽  
X Ray Diffraction ◽  
X Ray ◽  
Dimensional Network ◽  
Distorted Octahedral Coordination Geometry ◽  
Distorted Octahedral

The title two-dimensional coordination polymer, [Na(C2H8NO6P2)]n, was characterized using powder X-ray diffraction data and its structure refined using the Rietveld method. The asymmetric unit contains one Na+cation and one (1-azaniumylethane-1,1-diyl)bis(hydrogen phosphonate) anion. The central Na+cation exhibits distorted octahedral coordination geometry involving two deprotonated O atoms, two hydroxy O atoms and two double-bonded O atoms of the bisphosphonate anion. Pairs of sodium-centred octahedra share edges and the pairs are in turn connected to each other by the biphosphonate anion to form a two-dimensional network parallel to the (001) plane. The polymeric layers are connected by strong O—H...O hydrogen bonding between the hydroxy group and one of the free O atoms of the bisphosphonate anion to generate a three-dimensional network. Further stabilization of the crystal structure is achived by N—H...O and O—H...O hydrogen bonding.<!?tpb=18.7pt>

A two-dimensional copper(II) coordination polymer based on 2-propyl-1H-imidazole-4,5-dicarboxylic acid

2015 ◽  
Vol 71 (2) ◽  
pp. 152-154 ◽  
Author(s):  
Di-Chang Zhong ◽  
Hua-Bin Guo ◽  
Ji-Hua Deng ◽  
Ping Lian ◽  
Xu-Zhong Luo
Keyword(s):  
Hydrogen Bond ◽  
Carboxylic Acid ◽  
Dicarboxylic Acid ◽  
Three Dimensional ◽  
Acid Group ◽  
Two Dimensional ◽  
X Ray Diffraction ◽  
Carboxylic Acid Group ◽  
X Ray ◽  
Hydrogen Bond Interactions

Single-crystal X-ray diffraction analysis of poly[bis(μ2-5-carboxy-2-propyl-1H-imidazole-4-carboxylato-κ3N3,O4:O5)copper(II)], [Cu(C8H9N2O4)2)]n, indicates that one carboxylic acid group of the 2-propyl-1H-imidazole-4,5-dicarboxylic acid (H3PDI) ligand is deprotonated. The resulting H2PDI−anion, acting as a bridge, connects the CuIIcations to form a two-dimensional (4,4)-connected layer. Adjacent layers are further linked through interlayer hydrogen-bond interactions, resulting in a three-dimensional supramolecular structure.

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