Angle calculations for a (2+3)-type diffractometer: focus on area detectors

2010 ◽  
Vol 44 (1) ◽  
pp. 73-83 ◽  
Author(s):  
Christian M. Schlepütz ◽  
Simon O. Mariager ◽  
Stephan A. Pauli ◽  
Robert Feidenhans'l ◽  
Philip R. Willmott
Keyword(s):  
Direct Conversion ◽  
Reciprocal Space ◽  
Two Dimensional ◽  
X Ray Diffraction ◽  
X Ray ◽  
Sample Configuration ◽  
Diffraction Signal

Angle calculations for a (2+3)-type diffractometer are presented with comprehensive derivations for both cases of either a vertical or horizontal sample configuration. This work focuses on some particular aspects of using area detectors in surface X-ray diffraction, namely the role of the detector rotation and the direct conversion of the angle-resolved diffraction signal recorded by the detector into a two-dimensional slice through reciprocal space.

scholarly journals Integration techniques for surface X-ray diffraction data obtained with a two-dimensional detector

2014 ◽  
Vol 47 (1) ◽  
pp. 365-377 ◽  
Author(s):  
Jakub Drnec ◽  
Tao Zhou ◽  
Stelian Pintea ◽  
Willem Onderwaater ◽  
Elias Vlieg ◽  
...  
Keyword(s):  
Reciprocal Space ◽  
Two Dimensional ◽  
X Ray Diffraction ◽  
Integration Methods ◽  
X Ray ◽  
Structure Factors ◽  
Integration Techniques ◽  
Intensity Map ◽  
Integrated Intensities ◽  
Surface Diffraction

This article proposes two integration methods to determine the structure factors along a surface diffraction rod measured with a two-dimensional detector. The first method applies the classic way of calculating integrated intensities in angular space. This is adapted to work efficiently with two-dimensional data. The second method is based on integration in reciprocal space. An intensity map is created by converting the detected intensity pixel by pixel to the reciprocal space. The integration is then performed directly on this map. A theoretical framework, as well as a comparison between the two integration methods, is provided.

Analysis the Actual Nanostructure of α Phase Polyoctylfluorene Thin Film via Synchrotron Grazing-Incidence X-Ray Diffraction

2013 ◽  
Vol 333-335 ◽  
pp. 1832-1835
Author(s):  
Liu Ran Chen ◽  
Xi Chen ◽  
Ji Cai Liang ◽  
Ji Dong Zhang
Keyword(s):  
Thin Film ◽  
Grazing Incidence ◽  
Two Dimensional ◽  
X Ray Diffraction ◽  
One Dimensional ◽  
X Ray ◽  
Α Phase ◽  
Out Of Plane ◽  
Diffraction Signal

The nanostructure of α phase polyoctylfluorene thin film was characterized using normal X-ray diffraction, one-dimensional out-of-plane grazing incidence X-ray diffraction and two-dimensional grazing incidence X-ray diffraction with lab diffractometer and synchrotron diffractometer. The results show that using grazing incidence X-ray diffraction the weak diffraction signal of thin film can be observed after the elimination of background signals. Incorrect (h10) diffraction signals can be collected by lab diffractometer due to its low collimation and resolution, which can be overcome by using synchrotron diffractometer with high collimation and resolution that reveal the actual microstructure of polyoctylfluorene thin film.

Anisotropic strain in YBa2Cu3O7−δfilms analysed by deconvolution of two-dimensional intensity data

2001 ◽  
Vol 34 (1) ◽  
pp. 13-15
Author(s):  
J. Brötz ◽  
H. Fuess
Keyword(s):  
Superconducting Films ◽  
Reciprocal Space ◽  
Intensity Data ◽  
Two Dimensional ◽  
X Ray Diffraction ◽  
Diffraction Intensity ◽  
X Ray ◽  
Anisotropic Strain ◽  
Crystalline Substrate ◽  
Instrumental Resolution

The influence of the instrumental resolution on two-dimensional reflection profiles of epitaxic YBa2Cu3O7−δfilms on SrTiO3(001) has been studied in order to investigate the strain in the superconducting films. The X-ray diffraction intensity data were obtained by two-dimensional scans in reciprocal space (q-scan). Since the reflection broadening caused by the apparatus differs for each position in reciprocal space, a highly crystalline substrate was used as a standard. Thus it was possible to measure a standard very close to the YBa2Cu3O7−δreflections in reciprocal space. The two-dimensional deconvolution of reflections by a new computer program revealed an anisotropic strain of the two twinning systems of the film.

Structural role of tellurium in the minerals of the pearceite-polybasite group

2013 ◽  
Vol 77 (4) ◽  
pp. 419-428 ◽  
Author(s):  
L. Bindi ◽  
P. Voudouris ◽  
P. G. Spry
Keyword(s):  
Crystal Structure ◽  
Room Temperature ◽  
Atomic Displacement ◽  
Two Dimensional ◽  
X Ray Diffraction ◽  
X Ray ◽  
Dimensional Diffusion ◽  
Diffusion Paths ◽  
Linear Coordination

AbstractThe crystal structure of a Te-rich polybasite has been refined by means of X-ray diffraction data collected at room temperature (space group Pm1; R = 0.0505 for 964 observed reflections and 94 parameters; refined formula Ag14.46Cu1.54Sb1.58As0.42S9.67Te1.33). The structure comprises stacking of [(Ag, Cu)6(Sb, As)2(S, Te)7]2–A and [Ag9Cu(S, Te)2(S, Te)2]2+B layer modules in which Sb forms isolated SbS3 pyramids, as occurs typically in sulfosalts, Cu links two S atoms in a linear coordination and Ag occupies sites with coordination ranging from quasi linear to almost tetrahedral. The silver d10 ions are found in the B layer module along two-dimensional diffusion paths and their electron densities evidenced by means of a combination of a Gram-Charlier development of the atomic displacement factors and a split model. The Te-for-S substitution occurs at the same structural sites that Se substitutes for S in selenopolybasite and the Te occupancy at one of these sites is 0.49, thus suggesting the possibility that 'telluropolybasite' could be found in nature.

Two New Three-Dimensional Networks Constructed on Polyoxovanadates

2007 ◽  
Vol 60 (11) ◽  
pp. 871 ◽  
Author(s):  
Yan-fei Qi ◽  
Dongrong Xiao ◽  
Enbo Wang ◽  
Zhiming Zhang ◽  
Xinlong Wang
Keyword(s):  
Thermogravimetric Analysis ◽  
Rare Case ◽  
Three Dimensional ◽  
Network Connectivity ◽  
Two Dimensional ◽  
Crystal Data ◽  
X Ray Diffraction ◽  
Inorganic Hybrid ◽  
X Ray

To investigate the role of polyoxovanadates in network connectivity, two new organic–inorganic hybrid vanadates with three-dimensional entangled coordination frameworks, namely [Cu2(biim)3V4O12] 1 and [Co2(biim)3V4O12]·4H2O 2 have been synthesized and characterized by infrared (IR), thermogravimetric analysis (TGA), and single-crystal X-ray diffraction. Crystal data for compound 1: triclinic, P-1, a 9.504(2), b 10.650(2), c 11.993(2) Å; α 72.13(3), β 76.02(3), γ 65.40(3)°; V 1041.4(4) Å3, Z 2, R(final) 0.0492. Crystal data for compound 2: triclinic, P-1, a 9.037(3), b 10.577(2), c 11.9470(2) Å; α 87.80(3), β 81.71(3), γ 85.29(3)°; V 1125.8(4) Å3, Z 1, R(final) 0.0774. Compound 1 is a three-dimensional inclined hetero-catenated framework designed from two two-dimensional sub-layers, [Cu(biim)V4O12] and [Cu(biim)2]. Compound 2 is a rare case of a self-catenated ‘ilc’ network that displays an unusual 424·5·63 topology with the binuclear {Co2O4N6} units as eight-connected nodes.

Tubulin structure at intermediate resolution

1995 ◽  
Vol 53 ◽  
pp. 852-853
Author(s):  
K. H. Downing ◽  
S. G. Wolf ◽  
E. Nogales
Keyword(s):  
High Resolution ◽  
Structural Data ◽  
Therapeutic Drug ◽  
Zinc Ions ◽  
Two Dimensional ◽  
X Ray Diffraction ◽  
X Ray ◽  
Negative Stain ◽  
Functional Mechanisms ◽  
Tubulin Structure

Microtubules are involved in a host of critical cell activities, many of which involve transport of organelles through the cell. Different sets of microtubules appear to form during the cell cycle for different functions. Knowledge of the structure of tubulin will be necessary in order to understand the various functional mechanisms of microtubule assemble, disassembly, and interaction with other molecules, but tubulin has so far resisted crystallization for x-ray diffraction studies. Fortuitously, in the presence of zinc ions, tubulin also forms two-dimensional, crystalline sheets that are ideally suited for study by electron microscopy. We have refined procedures for forming the sheets and preparing them for EM, and have been able to obtain high-resolution structural data that sheds light on the formation and stabilization of microtubules, and even the interaction with a therapeutic drug.Tubulin sheets had been extensively studied in negative stain, demonstrating that the same protofilament structure was formed in the sheets and microtubules. For high resolution studies, we have found that the sheets embedded in either glucose or tannin diffract to around 3 Å.

Role of the Structure and Electronic Properties of Fe2O3-MoO3 Catalyst on the Dehydration of Isopropyl Alcohol

1993 ◽  
Vol 58 (7) ◽  
pp. 1591-1599 ◽  
Author(s):  
Abd El-Aziz A. Said
Keyword(s):  
Active Sites ◽  
Isopropyl Alcohol ◽  
Oxide Catalyst ◽  
Flow System ◽  
Charge Carriers ◽  
X Ray Diffraction ◽  
X Ray ◽  
Catalyst Composition ◽  
Surface Active

Molybdenum oxide catalyst doped or mixed with (1 - 50) mole % Fe3+ ions were prepared. The structure of the original samples and the samples calcined at 400 °C were characterized using DTA, X-ray diffraction and IR spectra. Measurements of the electrical conductivity of calcined samples with and without isopropyl alcohol revealed that the conductance increases on increasing the content of Fe3+ ions up to 50 mole %. The activation energies of charge carriers were determined in presence and absence of the alcohol. The catalytic dehydration of isopropyl alcohol was carried out at 250 °C using a flow system. The results obtained showed that the doped or mixed catalysts are active and selective towards propene formation. However, the catalyst containing 40 mole % Fe3+ ions exhibited the highest activity and selectivity. Correlations were attempted to the catalyst composition with their electronic and catalytic properties. Probable mechanism for the dehydration process is proposed in terms of surface active sites.

Synthesis and Structure of a Clathrated Two-Dimensional Metal-Organic Framework: [Cd(4,4'-bpy)2(H2O)2](ClO4)2·(L)2·H2O (L = Bis(1-pyrazinylethylidene)hydrazine)

2008 ◽  
Vol 73 (1) ◽  
pp. 24-31
Author(s):  
Dayu Wu ◽  
Genhua Wu ◽  
Wei Huang ◽  
Zhuqing Wang
Keyword(s):  
Metal Organic Framework ◽  
Channel Structure ◽  
Two Dimensional ◽  
X Ray Diffraction ◽  
Guest Molecules ◽  
X Ray ◽  
Square Planar ◽  
Metal Organic ◽  
Aqueous Meoh ◽  
Organic Framework

The compound [Cd(4,4'-bpy)2(H2O)2](ClO4)2·(L)2 was obtained by the reaction of Cd(ClO4)2, bis(1-pyrazinylethylidene)hydrazine (L) and 4,4'-bipyridine in aqueous MeOH. Single-crystal X-ray diffraction has revealed its two-dimensional metal-organic framework. The 2-D layers superpose on each other, giving a channel structure. The square planar grids consist of two pairs of shared edges with Cd(II) ion and a 4,4'-bipyridine molecule each vertex and side, respectively. The square cavity has a dimension of 11.817 × 11.781 Å. Two guest molecules of bis(1-pyrazinylethylidene)hydrazine are clathrated in every hydrophobic host cavity, being further stabilized by π-π stacking and hydrogen bonding. The results suggest that the hydrazine molecules present in the network serve as structure-directing templates in the formation of crystal structures.

scholarly journals Modeling of magneto-conductivity of bismuth selenide: a topological insulator

2021 ◽  
Vol 3 (4) ◽  
Author(s):  
Yogesh Kumar ◽  
Rabia Sultana ◽  
Prince Sharma ◽  
V. P. S. Awana
Keyword(s):  
Magnetic Field ◽  
Magnetic Fields ◽  
Single Crystal ◽  
Single Crystals ◽  
X Ray Diffraction ◽  
Field Range ◽  
X Ray ◽  
Bulk Carriers ◽  
Different Temperatures

AbstractWe report the magneto-conductivity analysis of Bi2Se3 single crystal at different temperatures in a magnetic field range of ± 14 T. The single crystals are grown by the self-flux method and characterized through X-ray diffraction, Scanning Electron Microscopy, and Raman Spectroscopy. The single crystals show magnetoresistance (MR%) of around 380% at a magnetic field of 14 T and a temperature of 5 K. The Hikami–Larkin–Nagaoka (HLN) equation has been used to fit the magneto-conductivity (MC) data. However, the HLN fitted curve deviates at higher magnetic fields above 1 T, suggesting that the role of surface-driven conductivity suppresses with an increasing magnetic field. This article proposes a speculative model comprising of surface-driven HLN and added quantum diffusive and bulk carriers-driven classical terms. The model successfully explains the MC of the Bi2Se3 single crystal at various temperatures (5–200 K) and applied magnetic fields (up to 14 T).

Sign in / Sign up

Export Citation Format

Share Document