Non-Isothermal Devitrification Study of Wollastonite-Tricalcium Phosphate Bioeutectic® Glass

2008 ◽  
Vol 396-398 ◽  
pp. 127-130 ◽  
Author(s):  
M. Magallanes-Perdomo ◽  
R. García Carrodeguas ◽  
P. Pena ◽  
P.N. De Aza ◽  
S. De Aza ◽  
...  
Keyword(s):  
Tricalcium Phosphate ◽  
Eutectic Composition ◽  
Rietveld Method ◽  
Glass Ceramics ◽  
Ambient Atmosphere ◽  
X Ray ◽  
Amorphous Content ◽  
Wide Range ◽  
Devitrification Process

This document describes and discusses the non-isothermal devitrification process of the wollastonite-tricalcium phosphate (W-TCP) eutectic glass. This eutectic glass has been studied in situ, from room temperature up to 1375 °C, by Neutron Diffractometry (ND) in vacuum. The data obtained were complemented and compared with those performed on ambient atmosphere by Differential Thermal Analysis (DTA) and with those of samples fired in air, at selected temperatures, and then cooled down and subsequently studied by laboratory X-ray Powder Diffraction (LXRD) and Field Emission Scanning Electron Microscopy (FE-SEM) fitted with Energy X-Ray Dispersive Spectroscopy (EDS). Selected samples have been investigated by quantitative full-phase analysis (including the amorphous content) using the Rietveld method. The experimental evidence indicates that the devitrification of W-TCP eutectic glass, begins at ~870°C, with the crystallization of a Ca-deficient apatite phase (Ca9.92(P5.85O23.54)(OH)2.03 (H2O)2.194) followed by wollastonite-2M (-CaSiO3) crystallization at 1006°C. At 1375°C the bio glassceramic is comprised of quasi-rounded colonies formed by a homogeneous mixture of pseudowollastonite (-CaSiO3) and -tricalcium phosphate (-Ca3(PO4)2). This microstructure corresponds to irregular eutectic structures and is similar to that of Bioeutectic® W-TCP material obtained previously, via controlled slow solidification of the eutectic composition, by some of the present authors. It has also been found that from the eutectic composition of the wollastonite – tricalcium phosphate binary system is possible to obtain a wide range of bio glass-ceramics through appropriate design of thermal treatments.

In Situ X-Ray Diffraction Studies of Crystallization Growth Behavior in ZnO-Bi2O3-B2O3 Glass as a Route to Functional Optical Devices

MRS Advances ◽  
2018 ◽  
Vol 3 (11) ◽  
pp. 563-567 ◽  
Author(s):  
Quentin Altemose ◽  
Katrina Raichle ◽  
Brittani Schnable ◽  
Casey Schwarz ◽  
Myungkoo Kang ◽  
...  
Keyword(s):  
Heat Treatment ◽  
Glass Ceramics ◽  
Treatment Temperature ◽  
Crystal Phase ◽  
X Ray Diffraction ◽  
X Ray ◽  
In Situ Xrd ◽  
Dsc Measurements ◽  
Transmission Window

ABSTRACTTransparent optical ZnO–Bi2O3–B2O3 (ZBB) glass-ceramics were created by the melt quenching technique. In this work, a melt of the glass containing stoichiometric ratios of Zn/Bi/B and As was studied. Differential scanning calorimeter (DSC) measurements was used to measure the thermal behavior. VIS/NIR transmission measurements were used to determine the transmission window. X-ray diffraction (XRD) was used to determine crystal phase. In this study, we explore new techniques and report a detailed study of in-situ XRD of the ZBB composition in order to correlate nucleation temperature, heat treatment temperature, and heat treatment duration with induced crystal phase.

scholarly journals X-Ray Fluorescence Analysis of a Gold Ibex and other Artifacts from Akrotiri

2019 ◽  
Vol 11 ◽  
Author(s):  
A. G. Karydas ◽  
T. Pantazis ◽  
C. Doumas ◽  
A. Vlachopoulos ◽  
P. Nomikos ◽  
...  
Keyword(s):  
Bulk Composition ◽  
Fluorescence Analysis ◽  
Wall Painting ◽  
Inorganic Elements ◽  
X Ray ◽  
Wide Range ◽  
Soldering Technology ◽  
Excavation Area

In-situ X-ray fluorescence analysis (XRF) of ancient artifacts from the excavation area was performed using a novel X-ray instrumentation, composed of a portable silicon PIN thermoelectrically cooled X-ray detector, a miniature X-ray source, and portable data acquisition devices. The main objective of the analyses in Akrotiri was to explore the potential of the technique to provide answers to a wide range of archaeometric questions regarding the bulk composition of metal alloys, especially of gold, the characterization of corrosion products in bronze artifacts, identification of inorganic elements which are fingerprints of the minerals used in wall-painting pigments, and of the painting materials and techniques used for the decoration of clay vase surfaces. Among the analysed artifacts are a unique gold ibex, a bronze dagger and blade, various pigments from the wall paintings of room 3 in Xeste 3, decoration pigments from rosettes of faience, a bichrome jug, and other clay vases. The results of the in-situ XRF survey, primarily those of the bulk composition and soldering technology of the gold ibex, are discussed and compared with literature.

scholarly journals In situ X-ray Diffraction Investigation of the Crystallisation of Perfluorinated Ce(IV)-based Metal-Organic Frameworks with UiO-66 and MIL-140 architectures

2020 ◽  
Author(s):  
Stephen Shearan ◽  
Jannick Jacobsen ◽  
Ferdinando Costantino ◽  
Roberto D’Amato ◽  
Dmitri Novikov ◽  
...  
Keyword(s):  
Crystal Growth ◽  
Metal Organic Frameworks ◽  
Building Blocks ◽  
Nucleation And Growth ◽  
X Ray Diffraction ◽  
X Ray ◽  
Rate Determining Step ◽  
Wide Range ◽  
Metal Organic

We report on the results of a thorough <i>in situ</i> synchrotron powder X-ray diffraction study of the crystallisation in aqueous medium of two recently discovered perfluorinated Ce(IV)-based metal-organic frameworks (MOFs), analogues of the already well investigated Zr(IV)-based UiO-66 and MIL-140A, namely, F4_UiO-66(Ce) and F4_MIL-140A(Ce). The two MOFs were originally obtained in pure form in similar conditions, using ammonium cerium nitrate and tetrafluoroterephthalic acid as building blocks, and small variations of the reaction parameters were found to yield mixed phases. Here, we investigate the crystallisation of these compounds <i>in situ</i> in a wide range of conditions, varying parameters such as temperature, amount of the protonation modulator nitric acid (HNO<sub>3</sub>) and amount of the coordination modulator acetic acid (AcOH). When only HNO<sub>3</sub> is present in the reaction environment, F4_MIL-140A(Ce) is obtained as a pure phase. Heating preferentially accelerates nucleation, which becomes rate determining below 57 °C, whereas the modulator influences nucleation and crystal growth to a similar extent. Upon addition of AcOH to the system, alongside HNO<sub>3</sub>, mixed-phased products, consisting of F4_MIL-140A(Ce) and F4_UiO-66(Ce), are obtained. In these conditions, F4_UiO-66(Ce) is always formed faster and no interconversion between the two phases occurs. In the case of F4_UiO-66(Ce), crystal growth is always the rate determining step. An increase in the amount of HNO<sub>3</sub> slows down both nucleation and growth rates for F4_MIL-140A(Ce), whereas nucleation is mainly affected for F4_UiO-66(Ce). In addition, a higher amount HNO<sub>3</sub> favours the formation of F4_MIL-140A(Ce). Similarly, increasing the amount of AcOH leads to slowing down of the nucleation and growth rate, but favours the formation of F4_UiO-66(Ce). The pure F4_UiO-66(Ce) phase could also be obtained when using larger amounts of AcOH in the presence of minimal HNO<sub>3</sub>. Based on these <i>in situ</i> results, a new optimised route to achieving a pure, high quality F4_MIL-140A(Ce) phase in mild conditions (60 °C, 1 h) is also identified.

Formation of Intermetallics and Grain Boundary Diffusion in Cu-Al and Au-Al Thin Film Couples

1981 ◽  
Vol 10 ◽  
Author(s):  
J. M. Vandenberg ◽  
F. J. A. Den Broeder ◽  
R. A. Hamm
Keyword(s):  
Thin Film ◽  
Hexagonal Phase ◽  
Interface Reaction ◽  
Aluminum Film ◽  
Temperature Dependent ◽  
X Ray ◽  
Wide Range ◽  
Al Thin Film ◽  
Rich Side

An in situ annealing X-ray study was applied to Cu-Al thin film couples over a wide range of copper-to-aluminum film ratios. This new technique, which has been previously described for a study on the Au-Al thin film system, enables us to make a temperature-dependent photographic X-ray analysis. The present study indicated that only a limited number of the wide variety of bulk phases form in the Cu-Al thin film interface, while some of these phases in the interface are transient. In the transient stages of the interface reaction, the f.c.c.-ordered phase β-Cu3A1 grows over the entire range of copper-to-aluminum film ratios after the first nucleation of CuA12, indicating a two-step nucleation reaction. On the aluminum-rich side, this phase transforms to a new ordered hexagonal phase β′. It could be interpreted as a superlattice of the metastable hexagonal ω phase occurring in zirconium-based alloys. The end phases are CuA1 and CuAl2.

Effects of Glass Elements on the Structural Evolution ofin situGrown Ferroelectric Perovskite Crystals in Sol-gel Derived Glass-ceramics

1997 ◽  
Vol 12 (4) ◽  
pp. 1131-1140 ◽  
Author(s):  
Kui Yao ◽  
Weiguang Zhu ◽  
Liangying Zhang ◽  
Xi Yao
Keyword(s):  
Crystallization Process ◽  
Sol Gel ◽  
Glass Ceramics ◽  
Structural Evolution ◽  
Dielectric Measurements ◽  
X Ray Diffraction ◽  
Process Change ◽  
X Ray ◽  
Ferroelectric Perovskite

Several ABO3perovskite ferroelectric crystals, PbTiO3, Pb(Zr, Ti)O3, and BaTiO3have beenin situgrown from amorphous gels with glass elements, and the structural evolution has been systematically investigated using x-ray diffraction (XRD), infrared spectra (IR), differential thermal analysis (DTA), thermogravimetric analysis (TGA), and dielectric measurements. It is found that in the Si-contained glass-ceramic systems, Si and B glass elements are incorporated into the crystalline structures, resulting in the variation of the crystallization process, change of lattice constant, and dielectric properties. Some metastable phases expressed by a general formula AxByGzOw(A = Pb and Ba; B = Zr and Ti; G for glass elements, especially for Si) have been observed and discussed.

scholarly journals Applications with a brighter X-ray source and new detectors from Agilent

2014 ◽  
Vol 70 (a1) ◽  
pp. C1734-C1734
Author(s):  
Zoltan Gal ◽  
Tadeusz Skarzynski ◽  
Fraser White ◽  
Oliver Presly ◽  
Adrian Jones ◽  
...  
Keyword(s):  
Data Quality ◽  
Single Crystal ◽  
Measurement System ◽  
Single Crystal Diffraction ◽  
X Ray ◽  
Vacuum Technology ◽  
Intelligent Measurement ◽  
Wide Range

Agilent Technologies develop and supply X-ray systems for single-crystal diffraction research, including the SuperNova; a compact, highly reliable and very low maintenance instrument providing X-ray data of the highest quality; and the PX Scanner for testing and characterization of protein crystals in their original crystallization drops (in-situ). The SuperNova and PX Scanner are constantly improving, with recent enhancements including a new range of detectors using an Intelligent Measurement System. The Eos S2, Atlas S2 and Titan S2 detector range employs a smart sensitivity control of the electronic gain and is capable of instantaneously switching its binning modes thus providing unprecedented flexibility in tuning every exposure to provide the highest data quality for a wide range of experiments. We have also developed a completely new micro-focus X-ray source based on Gradient Vacuum technology, with novel filament and target designs. This novel source is an integral part of the new Agilent GV1000 X-ray diffractometer, which has been designed for applications that require even higher brightness of the X-ray beam.

In Situ Studies of the Processing of Sol-Gel Produced Amorphous Materials Using Xanes, Saxs and Curved Image Plate XRD

1999 ◽  
Vol 590 ◽  
Author(s):  
DM Pickup ◽  
G Mountjoy ◽  
RJ Newport ◽  
ME Smith ◽  
GW Wallidge ◽  
...  
Keyword(s):  
Amorphous Materials ◽  
Sol Gel ◽  
Heat Treatments ◽  
Silica Gels ◽  
Ex Situ ◽  
High Count ◽  
X Ray ◽  
Image Plate ◽  
Wide Range

ABSTRACTSol-gel produced mixed oxide materials have been extensively studied using conventional, ex situ structural techniques. Because the structure of these materials is complex and dependent on preparation conditions, there is much to be gained from in situ techniques: the high brightness of synchrotron x-ray sources makes it possible to probe atomic structure on a short timescale, and hence in situ. Here we report recent results for mixed titania- (and some zirconia-) silica gels and xerogels. Titania contents were in the range 8–18 mol%, and heat treatments up to 500°C were applied. The results have been obtained from intrinsically rapid synchrotron x-ray experiments: i) time-resolved small angle scattering, using a quadrant detector, to follow the initial stages of aggregation between the sol and the gel; ii) the use of a curved image plate detector in diffraction, which allowed the simultaneous collection of data across a wide range of scattering at high count rate, to study heat treatments; and iii) x-ray absorption spectroscopy to explore the effects of ambient moisture on transition metal sites.

In Situ Synchrotron X-ray Absorption Experiments and Modelling of the Growth Rates of Electrochemically Deposited ZnO Nanostructures

2007 ◽  
Vol 1017 ◽  
Author(s):  
Bridget Ingham ◽  
Benoit N. Illy ◽  
Jade R. Mackay ◽  
Stephen P. White ◽  
Shaun C. Hendy ◽  
...  
Keyword(s):  
Growth Rates ◽  
High Resolution Electron Microscopy ◽  
Ex Situ ◽  
X Ray ◽  
Deposition Parameters ◽  
Wide Range ◽  
Electrochemically Deposited ◽  
Electrochemical Current ◽  
X Ray Absorption

AbstractZnO is known to produce a wide variety of nanostructures that have enormous scope for optoelectronic applications. Using an aqueous electrochemical deposition technique, we are able to tightly control a wide range of deposition parameters (Zn2+ concentration, temperature, potential, time) and hence the resulting deposit morphology. By simultaneously conducting synchrotron x-ray absorption spectroscopy (XAS) experiments during the deposition, we are able to directly monitor the growth rates of the nanostructures, as well as providing direct chemical speciation of the films. In situ experiments such as these are critical to understanding the nucleation and growth of such nanostructures.Recent results from in situ XAS synchrotron experiments demonstrate the growth rates as a function of potential and Zn2+ concentration. These are compared with the electrochemical current density recorded during the deposition, and the final morphology revealed through ex situ high resolution electron microscopy. The results are indicative of two distinct growth regimes, and simultaneous changes in the morphology are observed.These experiments are complemented by modelling the growth of the rods in the transport-limited case, using the Nernst-Planck equations in 2 dimensions, to yield the growth rate of the volume, length, and radius as a function of time.

A scanning Kelvin probe for synchrotron investigations: thein situdetection of radiation-induced potential changes

2011 ◽  
Vol 19 (1) ◽  
pp. 48-53 ◽  
Author(s):  
Bekir Salgin ◽  
Dirk Vogel ◽  
Diego Pontoni ◽  
Heiko Schröder ◽  
Bernd Schönberger ◽  
...  
Keyword(s):  
High Performance ◽  
Structural Changes ◽  
Kelvin Probe ◽  
X Ray ◽  
Scanning Kelvin Probe ◽  
Wide Range ◽  
First Results ◽  
Radiation Induced ◽  
Set Up

A wide range of high-performance X-ray surface/interface characterization techniques are implemented nowadays at every synchrotron radiation source. However, these techniques are not always `non-destructive' because possible beam-induced electronic or structural changes may occur during X-ray irradiation. As these changes may be at least partially reversible, anin situtechnique is required for assessing their extent. Here the integration of a scanning Kelvin probe (SKP) set-up with a synchrotron hard X-ray interface scattering instrument for thein situdetection of work function variations resulting from X-ray irradiation is reported. First results, obtained on bare sapphire and sapphire covered by a room-temperature ionic liquid, are presented. In both cases a potential change was detected, which decayed and vanished after switching off the X-ray beam. This demonstrates the usefulness of a SKP forin situmonitoring of surface/interface potentials during X-ray materials characterization experiments.

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