Reducing the background of ultra-low-temperature X-ray diffraction data through new methods and advanced materials

New methods and advanced materials that significantly reduce the background when collecting single-crystal X-ray diffraction data at ultra-low temperatures using a closed-cycle helium refrigerator are presented here. These include a magnetically controlled internal beamstop and a separate internal collimator that together completely remove the scattering contribution to the background from the beryllium vacuum chamber. Additionally, a new radiation shield made from flexible graphite significantly reduces the background and maintains excellent thermal properties. In combination these improvements have led to a sixfold reduction in the average intensity and a 15-fold reduction in peak intensity of the background observed for diffraction experiments conducted with a closed-cycle helium refrigerator. Moreover, access to ultra-low base temperatures, 2.05 K, has been maintained. The design and implementation of these methods are discussed along with a case study of vitamin C to demonstrate the effectiveness of the improvements.

Download Full-text

Pc Software for Rim Quantitative X-Ray Diffraction Analysis

Advances in X-ray Analysis ◽

10.1154/s0376030800023016 ◽

1995 ◽

Vol 39 ◽

pp. 589-597 ◽

Cited By ~ 1

Author(s):

BriantL. Davis

Keyword(s):

Quantitative Analysis ◽

Diffraction Data ◽

Intensity Ratio ◽

Spectroscopic Method ◽

Xrd Analysis ◽

X Ray Diffraction ◽

X Ray ◽

New Methods ◽

Transformation Methods

Quantitative multicomponent analysis of phases by x-ray diffraction still remains one of the most difficult applications of any element or phase spectroscopic method. The level of quality of XRD quantitative analysis is largely in the hands of the operator, but several relatively new methods for processing basic diffraction data are becoming known and more frequently used, including fulltrace (observed and calculated) subtraction methods (Smith et al, 1988), Rietveld procedures (Bish and Howard, 1988; Taylor and Aldridge, 1993), and chemical “apportionment” target-transformation methods (Starks, et al, 1984). In spite of these new advances, the single or multiple peak reference intensity ratio (RIR, or kj) procedure remains a simple and attractive technique for routine quantitative XRD analysis (Schreiner, 1995; Snyder, 1992; Davis, 1992).

Download Full-text

DIALS – a toolbox for diffraction data analysis

Acta Crystallographica Section A Foundations and Advances ◽

10.1107/s2053273314085593 ◽

2014 ◽

Vol 70 (a1) ◽

pp. C1440-C1440 ◽

Cited By ~ 1

Author(s):

Luis Fuentes-Montero ◽

James Parkhurst ◽

Graeme Winter ◽

David Waterman ◽

Richard Gildea ◽

...

Keyword(s):

Data Analysis ◽

Open Source Software ◽

Diffraction Data ◽

Three Dimensional ◽

Macromolecular Crystallography ◽

X Ray Diffraction ◽

X Ray ◽

New Methods ◽

Software Toolbox ◽

Initial Focus

DIALS is a collaborative initiative to produce an open source software toolbox encompassing all aspects of diffraction data analysis, with an initial focus on X-ray diffraction data from synchrotrons and free-electron lasers for macromolecular crystallography. DIALS [1] has been developed as a modular plug-in framework that permits flexibility not only in the development of new methods and algorithms but also in the application of these methods to data analysis. DIALS builds on the cctbx [2] in addition to its own dedicated tool-kits. We will present the ideas behind DIALS and give examples of its versatility in permitting the use of several spot-finding and indexing schemes, global refinement and both two and three dimensional integration methods.

Download Full-text

High-pressure synthesis and crystal structure of the mixed-cation borate Ga4In4B15O33(OH)3

Zeitschrift für Naturforschung B ◽

10.1515/znb-2019-0014 ◽

2019 ◽

Vol 74 (4) ◽

pp. 357-363

Author(s):

Daniela Vitzthum ◽

Hubert Huppertz

Keyword(s):

Crystal Structure ◽

High Pressure ◽

High Temperature ◽

Diffraction Data ◽

X Ray Diffraction ◽

Synthesis And Crystal Structure ◽

X Ray ◽

Mixed Cation ◽

High Pressure High Temperature ◽

Pressure Synthesis

AbstractThe mixed cation triel borate Ga4In4B15O33(OH)3 was synthesized in a Walker-type multianvil apparatus at high-pressure/high-temperature conditions of 12.5 GPa and 1300°C. Although the product could not be reproduced in further experiments, its crystal structure could be reliably determined via single-crystal X-ray diffraction data. Ga4In4B15O33(OH)3 crystallizes in the tetragonal space group I41/a (origin choice 2) with the lattice parameters a = 11.382(2), c = 15.244(2) Å, and V = 1974.9(4) Å3. The structure of the quaternary triel borate consists of a complex network of BO4 tetrahedra, edge-sharing InO6 octahedra in dinuclear units, and very dense edge-sharing GaO6 octahedra in tetranuclear units.

Download Full-text

Crystallization and preliminary x-ray diffraction data of the cryptomonad biliprotein phycocyanin-645 from a Chroomonas spec.

Archives of Microbiology ◽

10.1007/bf00454927 ◽

1984 ◽

Vol 140 (2-3) ◽

pp. 202-205 ◽

Cited By ~ 14

Author(s):

Walter Morisset ◽

Werner Wehrmeyer ◽

Tilman Schirmer ◽

Wolfram Bode

Keyword(s):

Diffraction Data ◽

X Ray Diffraction ◽

X Ray

Download Full-text

Theoretically derived thermodynamic properties can be improved by the refinement of low-frequency modes against X-ray diffraction data

Chemical Communications ◽

10.1039/d1cc02608a ◽

2021 ◽

Author(s):

Anna Agnieszka Hoser ◽

Marcin Sztylko ◽

Damian Trzybiński ◽

Anders Østergaard Madsen

Keyword(s):

Thermodynamic Properties ◽

Dft Calculations ◽

Diffraction Data ◽

Molecular Crystals ◽

Low Frequency ◽

X Ray Diffraction ◽

X Ray ◽

Efficient Approach

A framework for estimation of thermodynamic properties for molecular crystals via refinement of frequencies from DFT calculations against X-ray diffraction data is presented. The framework provides an efficient approach to...

Download Full-text

Transient phase fraction and dislocation density estimation from in-situ X-ray diffraction data with a low signal-to-noise ratio using a Bayesian approach to the Rietveld analysis

Materials Characterization ◽

10.1016/j.matchar.2020.110860 ◽

2020 ◽

pp. 110860

Author(s):

Manfred Wiessner ◽

Paul Angerer ◽

Sybrand van der Zwaag ◽

Ernst Gamsjäger

Keyword(s):

Dislocation Density ◽

Density Estimation ◽

Diffraction Data ◽

Signal To Noise Ratio ◽

Rietveld Analysis ◽

Transient Phase ◽

X Ray Diffraction ◽

Signal To Noise ◽

X Ray

Download Full-text

Single-crystal investigation of Ce5AgxGe4−x (x = 0.1−1.08) with Sm5Ge4 type

Zeitschrift für Naturforschung B ◽

10.1515/znb-2020-0091 ◽

2020 ◽

Vol 75 (8) ◽

pp. 765-768

Author(s):

Bohdana Belan ◽

Dorota Kowalska ◽

Mariya Dzevenko ◽

Mykola Manyako ◽

Roman Gladyshevskii

Keyword(s):

Crystal Structure ◽

Single Crystal ◽

Diffraction Data ◽

Binary Compound ◽

Lattice Parameters ◽

X Ray Diffraction ◽

Space Group ◽

X Ray

AbstractThe crystal structure of the phase Ce5AgxGe4−x (x = 0.1−1.08) has been determined using single-crystal X-ray diffraction data for Ce5Ag0.1Ge3.9. This phase is isotypic with Sm5Ge4: space group Pnma (No. 62), Pearson code oP36, Z = 4, a = 7.9632(2), b = 15.2693(5), c = 8.0803(2) Å; R1 = 0.0261, wR2 = 0.0460, 1428 F2 values and 48 variables. The two crystallographic positions 8d and 4c show Ge/Ag mixing, leading to a slight increase in the lattice parameters as compared to those of the pure binary compound Ce5Ge4.

Download Full-text

The modulated structure of Bi2Sr3−xCaxCu2O8: A commensurate model from single crystal X-ray diffraction data

Physica C Superconductivity ◽

10.1016/0921-4534(89)90396-1 ◽

1989 ◽

Vol 161 (5-6) ◽

pp. 598-606 ◽

Cited By ~ 49

Author(s):

G. Calestani ◽

C. Rizzoli ◽

M.G. Francesconi ◽

G.D. Andreetti

Keyword(s):

Single Crystal ◽

Diffraction Data ◽

X Ray Diffraction ◽

Modulated Structure ◽

X Ray

Download Full-text

Crystallographic features of ammonium fluoroelpasolites: dynamic orientational disorder in crystals of (NH4)3HfF7 and (NH4)3Ti(O2)F5

Acta Crystallographica Section B Structural Science Crystal Engineering and Materials ◽

10.1107/s2052520616017534 ◽

2017 ◽

Vol 73 (1) ◽

pp. 1-9 ◽

Cited By ~ 5

Author(s):

Anatoly A. Udovenko ◽

Alexander A. Karabtsov ◽

Natalia M. Laptash

Keyword(s):

Single Crystal ◽

Electron Density ◽

Diffraction Data ◽

Central Atom ◽

X Ray Diffraction ◽

Dynamic Nature ◽

Orientational Disorder ◽

High Quality ◽

Structural Units ◽

X Ray

A classical elpasolite-type structure is considered with respect to dynamically disordered ammonium fluoro-(oxofluoro-)metallates. Single-crystal X-ray diffraction data from high quality (NH4)3HfF7 and (NH4)3Ti(O2)F5 samples enabled the refinement of the ligand and cationic positions in the cubic Fm \bar 3 m (Z = 4) structure. Electron-density atomic profiles show that the ligand atoms are distributed in a mixed (split) position instead of 24e. One of the ammonium groups is disordered near 8c so that its central atom (N1) forms a tetrahedron with vertexes in 32f. However, a center of another group (N2) remains in the 4b site, whereas its H atoms (H2) occupy the 96k positions instead of 24e and, together with the H3 atom in the 32f position, they form eight spatial orientations of the ammonium group. It is a common feature of all ammonium fluoroelpasolites with orientational disorder of structural units of a dynamic nature.

Download Full-text