Simulations of femtosecond X-ray diffraction from unperturbed and rapidly heated single crystals

1999 ◽  
Vol 32 (4) ◽  
pp. 692-703 ◽  
Author(s):  
J. S. Wark ◽  
R. W. Lee
Keyword(s):  
Single Crystals ◽  
Time Scales ◽  
X Rays ◽  
Femtosecond Pulses ◽  
X Ray Diffraction ◽  
Similar Time ◽  
Short Pulses ◽  
X Ray ◽  
Laser Sources ◽  
Laser Heated

Simulations are presented of the dynamical diffraction of femtosecond pulses of X-rays from crystals whose structures are modified on similar time scales. Such simulations are of relevance to experiments in which short pulses of X-rays from synchrotron or laser sources are diffracted from rapidly laser-heated crystals.

Recrystallization of AA1050 Studied by 3DXRD

2006 ◽  
Vol 519-521 ◽  
pp. 1569-1578
Author(s):  
Dorte Juul Jensen
Keyword(s):  
Single Crystals ◽  
High Energy ◽  
Nucleation And Growth ◽  
X Rays ◽  
X Ray Diffraction ◽  
Orientation Relationships ◽  
X Ray ◽  
3 Dimensional ◽  
Kinetics Of

By 3 dimensional X-ray diffraction (3DXRD) using high energy X-rays from synchrotron sources it is possible to study in-situ the nucleation and growth during recrystallization. In this paper it is described and discussed how 3DXRD can supplement EBSP measurements of nucleation and growth. Three types of studies are considered: i) orientation relationships between nuclei and parent deformed matrix, ii) recrystallization kinetics of individual bulk grains and iii) filming of growing grains in deformed single crystals.

scholarly journals The diffraction of X-rays by age-hardening aluminium copper alloys.

1938 ◽  
Vol 167 (931) ◽  
pp. 526-538 ◽  
Author(s):  
G. D. Preston ◽  
William Lawrence Bragg
Keyword(s):  
Single Crystals ◽  
High Purity ◽  
Copper Alloy ◽  
Copper Alloys ◽  
Age Hardening ◽  
X Rays ◽  
X Ray Diffraction ◽  
X Ray ◽  
Aluminium Copper ◽  
The Wire

The object of this paper is to draw attention to certain peculiarities in the X-ray diffraction spectra obtained from single crystals of an alloy of aluminium with 4% by weight of copper. The experiments described below were carried out during an investigation into the property of age-hardening exhibited by these alloys, in the hope that some light would be throuwn on the processes preceding precipitation of the compound CuAl 2 , which are generally regarded as being the cause of the hardening in alloys of the Duralumin class, of which the simple 4% copper alloy is the prototype. The material used in the investigation was prepared from aluminium of high purity and after casting the ingots were forged and then draws into wires of 1 mm. diameter. Pieces of the wire after annealing at 500° C. contained crystals of sufficient size (2-5 mm. in length) for X-ray examination by the oscillating crystal and Laue methods.

Integrated X-Ray Diffraction Intensities from Single Crystals

1959 ◽  
Vol 3 ◽  
pp. 255-267
Author(s):  
Henry Chessin
Keyword(s):  
Single Crystals ◽  
Rapid Method ◽  
X Rays ◽  
X Ray Diffraction ◽  
X Ray ◽  
Intensity Measurements ◽  
Integrated Intensities

AbstractThe advantages and accuracy of counter equipment for the measurement of the intensity of scattered X-rays from small single crystals are discussed and illustrated. Several precautions necessary to obtain reliable intensity measurements are discussed. The equi-inclination method of inspecting all accessible reflections is treated in detail. The practicality of the stationary crystal method for determining integrated intensities, in principle the most accurate and rapid method, is demonstrated. Suggestions for improving the accuracy and speed of collecting data are made.

First-, second- and third-order correlation function in time-resolved X-ray diffraction experiments

2004 ◽  
Vol 37 (3) ◽  
pp. 445-450 ◽  
Author(s):  
Simone Techert
Keyword(s):  
Structural Changes ◽  
X Rays ◽  
X Ray Diffraction ◽  
Structural Reorganization ◽  
Third Order ◽  
Time Resolved ◽  
Pump Probe ◽  
X Ray ◽  
Laser Systems ◽  
Laser Sources

In the past decade, sustained progress has been made in the field of time-resolved X-ray diffraction and photocrystallography. Laser systems have been developed rapidly, and the combination of pulsed laser sources with pulsed X-ray sources, particularly by using synchrotron X-ray radiation and X-rays generated by plasma sources, has made the application of pump-probe schemes routine. So far, however, most studies have been focused on two questions: (i) the refinement of structural changes during the course of a reaction, and (ii) possible relations between transient structural changes and the intermediates found by optical spectroscopy. In this work, a kinetic description for different time laws in time-resolved X-ray diffraction experiments is derived in the framework of time-dependent correlation functions. The derived time laws were applied to time-resolved studies on a [2+2] photodimerization and a reversible reaction undergoing structural reorganization.

scholarly journals X-ray diffraction using focused-ion-beam-prepared single crystals

2020 ◽  
Vol 53 (3) ◽  
pp. 614-622
Author(s):  
Tina Weigel ◽  
Claudia Funke ◽  
Matthias Zschornak ◽  
Thomas Behm ◽  
Hartmut Stöcker ◽  
...  
Keyword(s):  
Single Crystal ◽  
Single Crystals ◽  
Focused Ion Beam ◽  
Ion Beam ◽  
Preparation Technique ◽  
X Rays ◽  
X Ray Diffraction ◽  
Electron Densities ◽  
X Ray ◽  
Absorption Correction

High-quality single-crystal X-ray diffraction measurements are a prerequisite for obtaining precise and reliable structure data and electron densities. The single crystal should therefore fulfill several conditions, of which a regular defined shape is of particularly high importance for compounds consisting of heavy elements with high X-ray absorption coefficients. The absorption of X-rays passing through a 50 µm-thick LiNbO3 crystal can reduce the transmission of Mo Kα radiation by several tens of percent, which makes an absorption correction of the reflection intensities necessary. In order to reduce ambiguities concerning the shape of a crystal, used for the necessary absorption correction, a method for preparation of regularly shaped single crystals out of large samples is presented and evaluated. This method utilizes a focused ion beam to cut crystals with defined size and shape reproducibly and carefully without splintering. For evaluation, a single-crystal X-ray diffraction study using a laboratory diffractometer is presented, comparing differently prepared LiNbO3 crystals originating from the same macroscopic crystal plate. Results of the data reduction, structure refinement and electron density reconstruction indicate qualitatively similar values for all prepared crystals. Thus, the different preparation techniques have a smaller impact than expected. However, the atomic coordinates, electron densities and atomic charges are supposed to be more reliable since the focused-ion-beam-prepared crystal exhibits the smallest extinction influences. This preparation technique is especially recommended for susceptible samples, for cases where a minimal invasive preparation procedure is needed, and for the preparation of crystals from specific areas, complex material architectures and materials that cannot be prepared with common methods (breaking or grinding).

X-ray diffraction properties of curved crystal diffractors

1992 ◽  
Vol 50 (2) ◽  
pp. 1734-1735
Author(s):  
W. Z. Chang ◽  
D. B. Wittry
Keyword(s):  
Diffraction Theory ◽  
X Rays ◽  
Diffraction Image ◽  
X Ray Diffraction ◽  
Rocking Curve ◽  
X Ray ◽  
Bent Crystal ◽  
Diffraction Geometry ◽  
Crystal Parameter ◽  
Quantitative Procedure

Since Du Mond and Kirkpatrick first discussed the principle of a bent crystal spectrograph in 1930, curved single crystals have been widely utilized as spectrometric monochromators as well as diffractors for focusing x rays diverging from a point. Curved crystal diffraction theory predicts that the diffraction parameters - the rocking curve width w, and the peak reflection coefficient r of curved crystals will certainly deviate from those of their flat form. Due to a lack of curved crystal parameter data in current literature and the need for optimizing the choice of diffraction geometry and crystal materials for various applications, we have continued the investigation of our technique presented at the last conference. In the present abstract, we describe a more rigorous and quantitative procedure for measuring the parameters of curved crystals.The diffraction image of a singly bent crystal under study can be obtained by using the Johann geometry with an x-ray point source.

Effect of trytophan as dopant on potassium acid phthalate single crystals

2019 ◽  
Author(s):  
Chem Int
Keyword(s):  
Single Crystals ◽  
Room Temperature ◽  
Visible Region ◽  
X Ray Diffraction ◽  
X Ray ◽  
Slow Evaporation Technique ◽  
Absorption Studies ◽  
Evaporation Technique ◽  
Potassium Acid Phthalate ◽  
Acid Phthalate

Optically transparent single crystals of potassium acid phthalate (KAP, 0.5 g) 0.05 g and 0.1 g (1 and 2 mol %) trytophan were grown in aqueous solution by slow evaporation technique at room temperature. Single crystal X- ray diffraction analysis confirmed the changes in the lattice parameters of the doped crystals. The presence of functional groups in the crystal lattice has been determined qualitatively by FTIR analysis. Optical absorption studies revealed that the doped crystals possess very low absorption in the entire visible region. The dielectric constant has been studied as a function of frequency for the doped crystals. The thermal stability was evaluated by TG-DSC analysis.

scholarly journals Some Novel Cobalt Diphenylphosphine Complexes: Synthesis, Characterization, and Behavior in the Polymerization of 1,3-Butadiene

Molecules ◽  
2021 ◽  
Vol 26 (13) ◽  
pp. 4067
Author(s):  
Giovanni Ricci ◽  
Giuseppe Leone ◽  
Giorgia Zanchin ◽  
Benedetta Palucci ◽  
Alessandra Forni ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Single Crystals ◽  
The Novel ◽  
X Ray Diffraction ◽  
X Ray ◽  
And Behavior

Some novel cobalt diphenylphosphine complexes were synthesized by reacting cobalt(II) chloride with (2-methoxyethyl)diphenylphosphine, (2-methoxyphenyl)diphenylphosphine, and 2-(1,1-dimethylpropyl)-6-(diphenylphosphino)pyridine. Single crystals suitable for X-ray diffraction studies were obtained for the first two complexes, and their crystal structure was determined. The novel compounds were then used in association with methylaluminoxane (MAO) for the polymerization of 1,3-butadiene, and their behavior was compared with that exhibited in the polymerization of the same monomer by the systems CoCl2(PnPrPh2)2/MAO and CoCl2(PPh3)2/MAO. Some significant differences were observed depending on the MAO/Co ratio used, and a plausible interpretation for such a different behavior is proposed.

scholarly journals Growth of sillenite Bi12FeO20 single crystals: structural, thermal, optical, photocatalytic features and first principle calculations

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Durga Sankar Vavilapalli ◽  
Ambrose A. Melvin ◽  
F. Bellarmine ◽  
Ramanjaneyulu Mannam ◽  
Srihari Velaga ◽  
...  
Keyword(s):  
Single Crystal ◽  
Single Crystals ◽  
Photoelectron Spectroscopy ◽  
Diffraction Method ◽  
Lattice Parameter ◽  
First Principle ◽  
X Ray Diffraction ◽  
X Ray ◽  
First Principle Calculations ◽  
Photodegradation Efficiency

AbstractIdeal sillenite type Bi12FeO20 (BFO) micron sized single crystals have been successfully grown via inexpensive hydrothermal method. The refined single crystal X-ray diffraction data reveals cubic Bi12FeO20 structure with single crystal parameters. Occurrence of rare Fe4+ state is identified via X-ray photoelectron spectroscopy (XPS) and X-ray absorption spectroscopy (XAS). The lattice parameter (a) and corresponding molar volume (Vm) of Bi12FeO20 have been measured in the temperature range of 30–700 °C by the X-ray diffraction method. The thermal expansion coefficient (α) 3.93 × 10–5 K−1 was calculated from the measured values of the parameters. Electronic structure and density of states are investigated by first principle calculations. Photoelectrochemical measurements on single crystals with bandgap of 2 eV reveal significant photo response. The photoactivity of as grown crystals were further investigated by degrading organic effluents such as Methylene blue (MB) and Congo red (CR) under natural sunlight. BFO showed photodegradation efficiency about 74.23% and 32.10% for degrading MB and CR respectively. Interesting morphology and microstructure of pointed spearhead like BFO crystals provide a new insight in designing and synthesizing multifunctional single crystals.

scholarly journals From Femtoseconds to Hours–Measuring Dynamics over 18 Orders of Magnitude with Coherent X-rays

2021 ◽  
Vol 11 (13) ◽  
pp. 6179
Author(s):  
Felix Lehmkühler ◽  
Wojciech Roseker ◽  
Gerhard Grübel
Keyword(s):  
Time Scales ◽  
Free Electron Laser ◽  
Photon Correlation Spectroscopy ◽  
Signal To Noise Ratio ◽  
Coherent Scattering ◽  
Correlation Spectroscopy ◽  
X Rays ◽  
Photon Correlation ◽  
X Ray ◽  
Scattering Technique

X-ray photon correlation spectroscopy (XPCS) enables the study of sample dynamics between micrometer and atomic length scales. As a coherent scattering technique, it benefits from the increased brilliance of the next-generation synchrotron radiation and Free-Electron Laser (FEL) sources. In this article, we will introduce the XPCS concepts and review the latest developments of XPCS with special attention on the extension of accessible time scales to sub-μs and the application of XPCS at FELs. Furthermore, we will discuss future opportunities of XPCS and the related technique X-ray speckle visibility spectroscopy (XSVS) at new X-ray sources. Due to its particular signal-to-noise ratio, the time scales accessible by XPCS scale with the square of the coherent flux, allowing to dramatically extend its applications. This will soon enable studies over more than 18 orders of magnitude in time by XPCS and XSVS.

Sign in / Sign up

Export Citation Format

Share Document