scholarly journals CrisDi School: disseminating crystallography in Piedmont, Italy

2014 ◽  
Vol 70 (a1) ◽  
pp. C1277-C1277
Author(s):  
Domenica Marabello ◽  
Angelo Agostino ◽  
Piera Benna ◽  
Giovanna Dinardo ◽  
Carlo Lamberti ◽  
...  
Keyword(s):  
Large Scale ◽  
Kinetic Studies ◽  
Research Centre ◽  
Main Task ◽  
X Rays ◽  
X Ray Diffraction ◽  
Time Resolved ◽  
New Methodologies ◽  
The University ◽  
Basic Level

The Interdepartmental Research Centre for the Development of Crystallography (CrisDi) aims to be an institution of reference for researchers at the University of Turin interested on the field of diffraction (X-rays, neutrons and electrons), to promote the knowledge and dissemination of crystallography, and to facilitate the access to available laboratory instrumentation (diffractometers and TEM) and to large scale facilities (synchrotron and neutron sources). CrisDi hosts scientists with interest in the fields of solid state chemistry and physics, organic, inorganic, organometallic and theoretical chemistry, mineralogy, biology, pharmaceutical and agricultural sciences. The Centre encourages the design and the development of new methodologies and applications, and supports the enhancement of the available instruments. The submission of proposals at large scale instruments is encouraged specially for young researchers and PhD students. The cultural and scientific interchange among crystallographers coming from different disciplines is strongly encouraged by CrisDi. A main task of the CrisDi is the annual organization of a post-grade level School with a series of courses dedicated to: (i) basic level crystallography (symmetry, theory of diffraction, crystal-chemistry), diffraction techniques (single crystal and powder X-ray diffraction, neutron and electron scattering); (ii) advanced level (high temperature and high pressure structural studies, macromolecular crystallography, time resolved crystallography and kinetic studies); (iii) spectroscopic approaches (XAFS, XANES, XES and NMR) in crystallography. The school, which is held every year in May for about 20 ECTS equivalent, has no tuition fees and is also open to non-academia people.

Kinetics of high-pressure mineral phase transformations using in situ time-resolved X-ray diffraction in the Paris-Edinburgh cell: a practical guide for data acquisition and treatment

2008 ◽  
Vol 72 (2) ◽  
pp. 683-695 ◽  
Author(s):  
J. P. Perrillat
Keyword(s):  
High Pressure ◽  
Phase Transformations ◽  
Kinetic Studies ◽  
X Ray Diffraction ◽  
Time Resolved ◽  
X Ray ◽  
Practical Guide ◽  
Set Up ◽  
Isothermal Kinetic

AbstractSynchrotron X-ray diffraction (XRD) is a powerful technique to study in situ and in real-time the structural and kinetic processes of pressure-induced phase transformations. This paper presents the experimental set-up developed at beamline ID27 of the ESRF to perform time-resolved angle dispersive XRD in the Paris-Edinburgh cell. It provides a practical guide for the acquisition of isobaric-isothermal kinetic data and the construction of transformation-time plots. The interpretation of experimental data in terms of reaction mechanisms and transformation rates is supported by an overview of the kinetic theory of solid-solid transformations, with each step of data processing illustrated by experimental results of relevance to the geosciences. Reaction kinetics may be affected by several factors such as the sample microstructure, impurities or differential stress. Further high-pressure kinetic studies should investigate the influence of such processes, in order to acquire kinetic information more akin to natural or technological processes.

scholarly journals Experimental and numerical study of ultra-short laser-produced collimated Cu Kα X-ray source

2017 ◽  
Vol 35 (3) ◽  
pp. 442-449 ◽  
Author(s):  
R. Rathore ◽  
V. Arora ◽  
H. Singhal ◽  
T. Mandal ◽  
J.A. Chakera ◽  
...  
Keyword(s):  
Laser Intensity ◽  
Numerical Study ◽  
Low Cost ◽  
Laser Pulses ◽  
Photon Flux ◽  
X Rays ◽  
X Ray Diffraction ◽  
Time Resolved ◽  
X Ray ◽  
Short Laser Pulses

AbstractKα X-ray sources generated from the interaction of ultra-short laser pulses with solids are compact and low-cost source of ultra-short quasi-monochromatic X-rays compared with synchrotron radiation source. Development of collimated ultra-short Kα X-ray source by the interaction of 45 fs Ti:sapphire laser pulse with Cu wire target is presented in this paper. A study of the Kα source with laser parameters such as energy and pulse duration was carried out. The observed Kα X-ray photon flux was ~2.7 × 108 photons/shot at the laser intensity of ~2.8 × 1017 W cm−2. A model was developed to analyze the observed results. The Kα radiation was coupled to a polycapillary collimator to generate a collimated low divergence (0.8 mrad) X-ray beam. Such sources are useful for time-resolved X-ray diffraction and imaging studies.

In Situ Time-Resolved X-Ray Diffraction Investigation of the ω→ψ Transition in Al-Cu-Fe Quasicrystal-Forming Alloys

2007 ◽  
Vol 558-559 ◽  
pp. 943-947 ◽  
Author(s):  
E. Otterstein ◽  
R. Nicula ◽  
J. Bednarčík ◽  
M. Stir ◽  
E. Burkel
Keyword(s):  
Large Scale ◽  
Applied Pressure ◽  
High Temperature Phase ◽  
Temperature Phase ◽  
X Ray Diffraction ◽  
Time Resolved ◽  
X Ray ◽  
In Situ Xrd ◽  
Kinetics Of

Quasicrystals are aperiodic long-range ordered solids with a high potential for many modern applications. Interest is nowadays paid to the development of economically viable large-scale synthesis procedures of quasicrystalline materials involving solid-state transformations. The kinetics of the high-temperature phase transition from the complex ω-phase to the icosahedral quasicrystalline (iQC) ψ-phase in AlCuFe nanopowders was here examined by in-situ time-resolved X-ray diffraction experiments using synchrotron radiation. In-situ XRD experiments will allow insight on the influence of uniaxial applied pressure on the kinetics of phase transitions leading to the formation of single-phase QC nanopowders and further contribute to the optimization of sintering procedures for nano-quasicrystalline AlCuFe alloy powders.

scholarly journals Temperature-dependent kinetic pathways featuring distinctive thermal-activation mechanisms in structural evolution of ice VII

2020 ◽  
Vol 117 (27) ◽  
pp. 15437-15442 ◽  
Author(s):  
Chuanlong Lin ◽  
Xuqiang Liu ◽  
Xue Yong ◽  
John S. Tse ◽  
Jesse S. Smith ◽  
...  
Keyword(s):  
Thermal Activation ◽  
Large Scale ◽  
Materials Science ◽  
Structural Evolution ◽  
X Ray Diffraction ◽  
Temperature Dependent ◽  
Reduced Pressure ◽  
Time Resolved ◽  
Molecular Dynamics Calculations ◽  
Activation Mechanisms

Ice amorphization, low- to high-density amorphous (LDA-HDA) transition, as well as (re)crystallization in ice, under compression have been studied extensively due to their fundamental importance in materials science and polyamorphism. However, the nature of the multiple-step “reverse” transformation from metastable high-pressure ice to the stable crystalline form under reduced pressure is not well understood. Here, we characterize the rate and temperature dependence of the structural evolution from ice VII to ice I recovered at low pressure (∼5 mTorr) using in situ time-resolved X-ray diffraction. Unlike previously reported ice VII (or ice VIII)→LDA→ice I transitions, we reveal three temperature-dependent successive transformations: conversion of ice VII into HDA, followed by HDA-to-LDA transition, and then crystallization of LDA into ice I. Significantly, the temperature-dependent characteristic times indicate distinctive thermal activation mechanisms above and below 110–115 K for both ice VIII-to-HDA and HDA-to-LDA transitions. Large-scale molecular-dynamics calculations show that the structural evolution from HDA to LDA is continuous and involves substantial movements of the water molecules at the nanoscale. The results provide a perspective on the interrelationship of polyamorphism and unravel its underpinning complexities in shaping ice-transition kinetic pathways

scholarly journals Time-resolved X-ray diffraction at NERL

2001 ◽  
Vol 19 (1) ◽  
pp. 125-131 ◽  
Author(s):  
KENICHI KINOSHITA ◽  
HIDEKI HARANO ◽  
KOJI YOSHII ◽  
TAKERU OHKUBO ◽  
ATSUSHI FUKASAWA ◽  
...  
Keyword(s):  
Research Laboratory ◽  
Experimental Results ◽  
X Rays ◽  
Nuclear Engineering ◽  
X Ray Diffraction ◽  
Time Resolved ◽  
X Ray ◽  
Engineering Research ◽  
Fs Laser ◽  
Diffraction Patterns

For ultrafast material analyses, we constructed the time-resolved X-ray diffraction system utilizing ultrashort X-rays from laser-produced plasma generated by the 12-TW–50-fs laser at the Nuclear Engineering Research Laboratory. Ultrafast transient changes in laser-irradiated GaAs crystals were observed as X-ray diffraction patterns. Experimental results were compared with numerical analyses.

scholarly journals Measuring non-equilibrium dynamics in complex solids with ultrashort X-ray pulses

2019 ◽  
Vol 377 (2145) ◽  
pp. 20170478 ◽  
Author(s):  
Michele Buzzi ◽  
Michael Först ◽  
Andrea Cavalleri
Keyword(s):  
Electronic Structures ◽  
Research Trend ◽  
Strong Interactions ◽  
X Rays ◽  
X Ray Diffraction ◽  
Optical Pulses ◽  
Time Resolved ◽  
X Ray ◽  
Equilibrium Dynamics ◽  
External Perturbations

Strong interactions between electrons give rise to the complexity of quantum materials, which exhibit exotic functional properties and extreme susceptibility to external perturbations. A growing research trend involves the study of these materials away from equilibrium, especially in cases in which the stimulation with optical pulses can coherently enhance cooperative orders. Time-resolved X-ray probes are integral to this type of research, as they can be used to track atomic and electronic structures as they evolve on ultrafast timescales. Here, we review a series of recent experiments where femtosecond X-ray diffraction was used to measure dynamics of complex solids. This article is part of the theme issue ‘Measurement of ultrafast electronic and structural dynamics with X-rays’.

Synthesis Mechanisms of the Combustion Synthesis of IntermetCers Composites

2006 ◽  
Vol 45 ◽  
pp. 1029-1034 ◽  
Author(s):  
C. Curfs ◽  
A.E. Terry ◽  
G.B.M. Vaughan ◽  
Erich H. Kisi ◽  
M.A. Rodriguez ◽  
...  
Keyword(s):  
Combustion Synthesis ◽  
Nickel Aluminide ◽  
The Self ◽  
Scanning Electron Micrographs ◽  
X Rays ◽  
X Ray Diffraction ◽  
Time Resolved ◽  
Combustion Modes ◽  
Intermediate Phases ◽  
Diffraction Patterns

Combustion synthesis techniques have been applied to an equiatomic mixture of Aluminium, Nickel, Titanium and Carbon powders in order to obtain NiAl/TiC composites. Both combustion modes have been used: the Self-propagating High-temperature mode (SHS), in which the reaction propagates through the sample under the form of a heat wave and the Thermal Explosion mode (TES), in which the reaction occurs simultaneously in the complete sample. The reactions have been followed in-situ by time-resolved diffraction, using synchrotron X-rays for the SHS mode and neutrons for the TES mode. Scanning Electron Micrographs and X-ray diffraction patterns of the final product have shown that the same final products were obtained when the mixture was synthesised under both combustion modes: a composite made of small and round TiC particles (~1 micron) embedded into a matrix of larger NiAl grains (5 microns). However, the Time-Resolved Diffraction studies have shown that, even with the same final products, the two combustion modes follow two completely different routes. Thus, for the SHS mode, the reaction is triggered by the formation of Nickel Aluminide and 3 intermediate phases are observed, and for the TES mode, the self-sustained reaction starts with the formation of Titanium Carbide and no intermediate phases have been seen.

scholarly journals Kanzelhöhe Observatory: Instruments, Data Processing and Data Products

Solar Physics ◽  
2021 ◽  
Vol 296 (11) ◽  
Author(s):  
Werner Pötzi ◽  
Astrid Veronig ◽  
Robert Jarolim ◽  
Jenny Marcela Rodríguez Gómez ◽  
Tatiana Podlachikova ◽  
...  
Keyword(s):  
Large Scale ◽  
Environmental Research ◽  
Main Task ◽  
Solar Cycles ◽  
Quality Classification ◽  
Data Products ◽  
Long Time ◽  
Telescope Optics ◽  
High Level ◽  
The University

AbstractKanzelhöhe Observatory for Solar and Environmental Research (KSO) of the University of Graz (Austria) is in continuous operation since its foundation in 1943. Since the beginning, its main task was the regular observation of the Sun in full disc. In this long time span covering almost seven solar cycles, a substantial amount of data was collected, which is made available online. In this article we describe the separate processing steps from data acquisition to high level products for different observing wavelengths. First of all we present in detail the quality classification, which is important for further processing of the raw images. We show how we construct centre-to-limb variation (CLV) profiles and how we remove large scale intensity variations produced by the telescope optics in order to get images with uniform intensity and contrast. Another important point is an overview of the different data products from raw images to high contrast images with heliographic grids overlaid. As the data products are accessible via different sources, we also present how to get information about the availability and how to obtain these data. Finally, in an appendix, we describe in detail the information in the FITS headers, the file naming and the data hierarchy.

scholarly journals Small-angle scattering for beginners

2021 ◽  
Vol 54 (6) ◽  
Author(s):  
Cedric J. Gommes ◽  
Sebastian Jaksch ◽  
Henrich Frielinghaus
Keyword(s):  
Small Angle ◽  
Small Angle Scattering ◽  
X Rays ◽  
X Ray Diffraction ◽  
Experimental Conditions ◽  
Time Resolved ◽  
Characterization Methods ◽  
Angle Scattering

Many experimental methods are available for the characterization of nanostructures, but most of them are limited by stringent experimental conditions. When it comes to analysing nanostructures in the bulk or in their natural environment – even as ordinary as water at room temperature – small-angle scattering (SAS) of X-rays or neutrons is often the only option. The rapid worldwide development of synchrotron and neutron facilities over recent decades has opened unprecedented possibilities for using SAS in situ and in a time-resolved way. But, in spite of its huge potential in the field of nanomaterials in general, SAS is covered far less than other characterization methods in non-specialized curricula. Presented here is a rigorous discussion of small-angle scattering, at a technical level comparable to the classical undergraduate coverage of X-ray diffraction by crystals and which contains diffraction as a particular case.

scholarly journals Picosecond time-resolved X-ray diffraction from laser-shocked semiconductors

2004 ◽  
Vol 22 (3) ◽  
pp. 285-288 ◽  
Author(s):  
KAZUTAKA G. NAKAMURA ◽  
YOICHIRO HIRONAKA ◽  
HIDETAKA KAWANO ◽  
HIROAKI KISHIMURA ◽  
KEN-ICHI KONDO
Keyword(s):  
Shock Wave ◽  
Wave Propagation ◽  
Structural Dynamics ◽  
Lattice Deformation ◽  
X Rays ◽  
X Ray Diffraction ◽  
Time Resolved ◽  
X Ray ◽  
Femtosecond Laser Beam ◽  
Diffraction Patterns

Ultrashort pulsed hard X rays are generated by focusing an intense femtosecond laser beam onto metal targets. Kαemissions are obtained from a Cu target. Picosecond time-resolved X-ray diffraction is performed to investigate structural dynamics of laser-shocked semiconductors using the laser plasma X-ray pulses. Lattice deformation associated with shock-wave propagation is directly observed. Evolution of strain profiles inside the crystal is determined without disturbance from the time-resolved X-ray diffraction patterns.

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