scholarly journals Identification of inversion domains in KTiOPO4viaresonant X-ray diffraction

2015 ◽  
Vol 71 (4) ◽  
pp. 361-367 ◽  
Author(s):  
Federica Fabrizi ◽  
Pamela A. Thomas ◽  
Gareth Nisbet ◽  
Stephen P. Collins
Keyword(s):  
Bragg Reflection ◽  
Crystallographic Structure ◽  
X Ray Diffraction ◽  
X Ray ◽  
Polar Materials ◽  
Novel Method ◽  
Physical Phenomena ◽  
Non Destructive ◽  
Ray Methods

A novel method is presented for the identification of the absolute crystallographic structure in multi-domain polar materials such as ferroelectric KTiOPO4. Resonant (or `anomalous') X-ray diffraction spectra collected across the absorptionKedge of Ti (4.966 keV) on a single Bragg reflection demonstrate a huge intensity ratio above and below the edge, providing a polar domain contrast of ∼270. This allows one to map the spatial domain distribution in a periodically inverted sample, with a resolution of ∼1 µm achieved with a microfocused beam. This non-contact, non-destructive technique is well suited for samples of large dimensions (in contrast with traditional resonant X-ray methods based on diffraction from Friedel pairs), and its potential is particularly relevant in the context of physical phenomena connected with an absence of inversion symmetry, which require characterization of the underlying absolute atomic structure (such as in the case of magnetoelectric coupling and multiferroics).

The Characterization of Bovine Bone-Derived Hydroxyapatite Isolated Using Novel Non-Hazardous Method

2020 ◽  
Vol 45 ◽  
pp. 49-56
Author(s):  
Aniek Setiya Budiatin ◽  
Samirah ◽  
Maria Apriliani Gani ◽  
Wenny Putri Nilamsari ◽  
Chrismawan Ardianto ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Extraction Method ◽  
Bovine Bone ◽  
X Ray Diffraction ◽  
X Ray ◽  
Ft Ir ◽  
Novel Method ◽  
Scanning Electron

Bovine bone is a considerable source for the production of hydroxyapatite. The recent study reported a novel method to extract hydroxyapatite from bovine bone without producing hazardous residue. The bovine bones were cut and boiled in the opened chamber followed by boiling in pressurized tank. The bones were then soaked into 95% ethanol. Calcination was then conducted in 800°C, 900°C and 1,000°C, for 2 hours. The result was then grinded and sieved. The powder then was characterized using Fourier transform infrared (FT-IR), Scanning electron microscopy (SEM) and X-ray diffraction analysis (XRD) to measure the purity of hydroxyapatite. It is concluded that the hydroxyapatite derived from this process showed 100% purity, resulting 35.34 ± 0.39% w/w from the wet bone weight and 72.3% w/w from the dried weight. The present extraction method has been proven to yield high amount of pure hydroxyapatite as well as reducing the use of hazardous reagent.

scholarly journals Photoreversible interconversion of a phytochrome photosensory module in the crystalline state

2019 ◽  
Vol 117 (1) ◽  
pp. 300-307 ◽  
Author(s):  
E. Sethe Burgie ◽  
Jonathan A. Clinger ◽  
Mitchell D. Miller ◽  
Aaron S. Brewster ◽  
Pierre Aller ◽  
...  
Keyword(s):  
Single Crystal ◽  
Blue Light ◽  
Green Light ◽  
Crystallographic Structure ◽  
X Ray Diffraction ◽  
Major Barrier ◽  
X Ray ◽  
Spectroscopic Analyses ◽  
Serial Femtosecond Crystallography

A major barrier to defining the structural intermediates that arise during the reversible photointerconversion of phytochromes between their biologically inactive and active states has been the lack of crystals that faithfully undergo this transition within the crystal lattice. Here, we describe a crystalline form of the cyclic GMP phosphodiesterases/adenylyl cyclase/FhlA (GAF) domain from the cyanobacteriochrome PixJ inThermosynechococcus elongatusassembled with phycocyanobilin that permits reversible photoconversion between the blue light-absorbing Pb and green light-absorbing Pg states, as well as thermal reversion of Pg back to Pb. The X-ray crystallographic structure of Pb matches previous models, including autocatalytic conversion of phycocyanobilin to phycoviolobilin upon binding and its tandem thioether linkage to the GAF domain. Cryocrystallography at 150 K, which compared diffraction data from a single crystal as Pb or after irradiation with blue light, detected photoconversion product(s) based on Fobs− Fobsdifference maps that were consistent with rotation of the bonds connecting pyrrole rings C and D. Further spectroscopic analyses showed that phycoviolobilin is susceptible to X-ray radiation damage, especially as Pg, during single-crystal X-ray diffraction analyses, which could complicate fine mapping of the various intermediate states. Fortunately, we found that PixJ crystals are amenable to serial femtosecond crystallography (SFX) analyses using X-ray free-electron lasers (XFELs). As proof of principle, we solved by room temperature SFX the GAF domain structure of Pb to 1.55-Å resolution, which was strongly congruent with synchrotron-based models. Analysis of these crystals by SFX should now enable structural characterization of the early events that drive phytochrome photoconversion.

Physical Phenomena Leading to Melting of Metals

2017 ◽  
Vol 884 ◽  
pp. 3-17 ◽  
Author(s):  
Roberto Montanari ◽  
Alessandra Varone
Keyword(s):  
Dynamic Modulus ◽  
X Ray Diffraction ◽  
Mechanical Spectroscopy ◽  
Sharp Drop ◽  
X Ray ◽  
Novel Method ◽  
Diffraction Peaks ◽  
Pure Metals ◽  
Physical Phenomena ◽  
Specific Metal

Precursor phenomena of melting in pure metals and alloys have been investigated by means of Mechanical Spectroscopy (MS) and High Temperature X-ray Diffraction (HT-XRD). The examined materials were the pure metals In, Sn, Pb and Bi, and some alloys of the systems In-Sn and Pb-Bi with different compositions.MS tests have been carried out by means of a novel method developed by us that permits to operate in resonance conditions and employs hollow reeds of stainless steel containing the liquid metal. In all the metals a sharp drop of dynamic modulus and a Q-1 maximum were observed in a temperature range ΔT before melting that depends on the specific metal and its structure. Such anelastic behaviour is consistent with an increase of the interstitialcies concentration as predicted by the Granato’s theory.Moreover, HT-XRD evidenced that sudden grain re-orientation, shift and broadening of diffraction peaks occur just before the formation of the first liquid, therefore self-interstitials and vacancies seem to play a synergic role in melting. The increase of self-interstitials over ΔT has the effect of weakening interatomic bonds that favours the successive vacancy avalanche leading to the collapse of crystal lattice (melting).

Synthesis and Characterization of Low Density Bi-2223 Cuprates Superconductor Doped Eu2O3 Nanoparticles

2021 ◽  
Vol 317 ◽  
pp. 131-137
Author(s):  
Suhaimi Nurbaisyatul Ermiza ◽  
Azhan Hashim ◽  
Azman Kasim ◽  
Norazila Ibrahim ◽  
Siti Fatimah Saipuddin
Keyword(s):  
Solid State Reaction Method ◽  
Synthesis And Characterization ◽  
Crystallographic Structure ◽  
Low Density ◽  
Superconducting Properties ◽  
X Ray Diffraction ◽  
Conventional Solid State Reaction ◽  
X Ray ◽  
Resistivity Measurements

Bi1.6Pb0.4Sr2Ca2-xEuxCu3Oδ cuprates superconductor doped with Eu nanoparticles (x = 0.0000, 0.0025, 0.0200 and 0.0500) were synthesized through conventional solid state reaction method. Crystalline sucrose was added during pelletization and burn at 400°C for two hours to create low density sample. The effect of doping Eu2O3 nanoparticles on the structural and superconducting properties by means of critical temperature (Tc), critical current density (Jc), X-ray diffraction (XRD) together with Field Emission Scanning Electron Microscopy (FESEM) and Alternating Current Susceptibility (ACS) were studied. Based on XRD analyses, the crystallographic structure has shown slightly changed from tetragonal to orthorhombic. The amount of 2223 phase gradually decreased with the increment of Eu concentration which indicates that Eu nanoparticles substitution favours the growth of 2212 phases. The resistivity measurements show that the highest Tcvalue for doped samples found at 90 K for x = 0.0025. The FESEM images showed that the plate-like grains become smaller and distributed randomly without specific alignment due to the increment of Eu concentration.

PREPARATION AND CHARACTERIZATION OF CIS POWDERS BY A FACILE REFLUXING REACTION ROUTE

2013 ◽  
Vol 12 (05) ◽  
pp. 1350031
Author(s):  
J. C. ZHOU ◽  
Y. Y. WANG ◽  
X. L. GONG ◽  
S. W. LI
Keyword(s):  
Single Phase ◽  
Stoichiometric Composition ◽  
Chalcopyrite Structure ◽  
Crystallographic Structure ◽  
X Ray Diffraction ◽  
Reaction Route ◽  
X Ray ◽  
Structure Morphology ◽  
Short Time

CuInSe 2 (CIS)-based powders were successfully prepared by a facile refluxing reaction route using metal halides and Se / S powder as raw starting materials. The phase and crystallographic structure, morphology, chemical composition of the products were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDS). It is found that single phase CIS powders with chalcopyrite structure can be prepared in a relatively short time using triethylenetetramine as the solvent; the most suitable reaction temperature and time are 200°C, 1–2 h, respectively. CuIn ( S x Se 1-x)2 powders were also prepared by refluxing reaction route using the mixed solvent of triethylenetetramine–glycol (1:1, v/v). The characterizations showed that the CuIn ( S x Se 1-x)2 has single chalcopyrite phase, and the stoichiometric composition closely follows the primary mixed ratio. The morphology of CuIn ( S x Se 1-x)2 is close to spheres, and the particle sizes become distinctly smaller with the incorporation of S . A possible formation mechanism of CuInSe 2 was put forward and briefly discussed.

X-Ray Diffraction Study of Cold Sprayed Ni-20Cr and Ni-50Cr Coatings on Boiler

2012 ◽  
Vol 620 ◽  
pp. 257-262 ◽  
Author(s):  
Niraj Bala ◽  
Harpreet Singh ◽  
Satya Prakash
Keyword(s):  
Chemical Composition ◽  
Xrd Analysis ◽  
Crystallographic Structure ◽  
X Ray Diffraction ◽  
X Ray ◽  
Xrd Study ◽  
Non Destructive ◽  
Sprayed Coatings ◽  
Boiler Steels ◽  
Better Than

X-ray diffraction (XRD) is a versatile, non-destructive technique that reveals detailed information about the chemical composition and crystallographic structure of materials. In this work Ni-20Cr and Ni-50Cr coatings were deposited on two boiler steels namely T22 and SA 516 steel. The measurement of residual stresses of these cold sprayed coatings was done with the help of X-ray diffraction technique. This paper discussed the XRD study of the as-sprayed coatings. Further the XRD technique was used to study the uncoated and coated steels after cyclic exposure to air, molten salt [Na2SO4-60%V2O5], and actual boiler environments. The results obtained from the XRD analysis have been shown. The weight change results showed that the coated steels performed better than their uncoated counterparts which might be attributed to the formation of protective phases.

Non-destructive thickness characterization of Si based heterostructure by X-ray diffraction and reflectivity

2011 ◽  
Vol 60 (1) ◽  
pp. 42-45 ◽  
Author(s):  
Xue-Chao Liu ◽  
M. Myronov ◽  
A. Dobbie ◽  
Van H. Nguyen ◽  
D.R. Leadley
Keyword(s):  
X Ray Diffraction ◽  
X Ray ◽  
Non Destructive

Non-Destructive Micro-Chemical and Micro-Luminescence Characterization of Jadeite

2016 ◽  
Vol 22 (6) ◽  
pp. 1304-1315 ◽  
Author(s):  
Alejandro Mitrani Viggiano ◽  
José Luis Ruvalcaba Sil ◽  
Mayra D. Manrique Ortega ◽  
Victoria Corregidor Berdasco
Keyword(s):  
Ion Beam ◽  
Nuclear Microprobe ◽  
X Ray Diffraction ◽  
Mineral Contents ◽  
Spanish Conquest ◽  
Distinctive Features ◽  
X Ray ◽  
Fourier Transformed Infrared Spectroscopy ◽  
Non Destructive

AbstractJadeite was greatly appreciated by pre-Hispanic cultures in Mesoamerica. Despite its importance, knowledge of its mining sources was lost after the Spanish conquest. In the 1950s the only confirmed jadeite deposits in Mesoamerica were found in the Motagua River Fault (MRF), Guatemala. The aim of this study is to present a methodology that is appropriate for the study of archeological jadeite objects using non-destructive spectroscopic and micro-ion beam analysis techniques. This methodology has been applied to perform mineral, elemental, and luminescence characterization of five jadeite samples from the MRF, with white, lilac, and green colors. Fourier-transformed infrared spectroscopy and X-ray diffraction analysis confirmed the presence of jadeite, albite, and omphacite as the main mineral phases in the samples. Elemental maps using particle-induced X-ray emission (PIXE) with a nuclear microprobe and elemental concentration analysis from individual mineral grains using micro-PIXE coupled with micro-ionoluminescence (IL) allowed the detection of minor feldspar, titanite, and grossular mineral contents. Distinctive features from the mineral, elemental, and luminescence characterization have been found that allow the identification of these five jadeite samples.

scholarly journals X-ray fan beam coded aperture transmission and diffraction imaging for fast material analysis

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Stefan Stryker ◽  
Joel A. Greenberg ◽  
Shannon J. McCall ◽  
Anuj J. Kapadia
Keyword(s):  
High Resolution ◽  
Spatial Resolution ◽  
Imaging System ◽  
Coded Aperture ◽  
X Ray Diffraction ◽  
X Ray ◽  
Transmission Imaging ◽  
Diffraction Imaging ◽  
Non Destructive ◽  
Ray Methods

AbstractX-ray transmission imaging has been used in a variety of applications for high-resolution measurements based on shape and density. Similarly, X-ray diffraction (XRD) imaging has been used widely for molecular structure-based identification of materials. Combining these X-ray methods has the potential to provide high-resolution material identification, exceeding the capabilities of either modality alone. However, XRD imaging methods have been limited in application by their long measurement times and poor spatial resolution, which has generally precluded combined, rapid measurements of X-ray transmission and diffraction. In this work, we present a novel X-ray fan beam coded aperture transmission and diffraction imaging system, developed using commercially available components, for rapid and accurate non-destructive imaging of industrial and biomedical specimens. The imaging system uses a 160 kV Bremsstrahlung X-ray source while achieving a spatial resolution of ≈ 1 × 1 mm2 and a spectral accuracy of > 95% with only 15 s exposures per 150 mm fan beam slice. Applications of this technology are reported in geological imaging, pharmaceutical inspection, and medical diagnosis. The performance of the imaging system indicates improved material differentiation relative to transmission imaging alone at scan times suitable for a variety of industrial and biomedical applications.

Sign in / Sign up

Export Citation Format

Share Document