scholarly journals Exploring the Dzi Bead with Synchrotron Light: XRD, XRF Imaging and μ-XANES Analysis

Heritage ◽  
2020 ◽  
Vol 3 (3) ◽  
pp. 1035-1045
Author(s):  
Averie Reinhardt ◽  
Renfei Feng ◽  
Qunfeng Xiao ◽  
Yongfeng Hu ◽  
Tsun-Kong Sham
Keyword(s):  
Hot Spots ◽  
Imaging Techniques ◽  
X Rays ◽  
X Ray Diffraction ◽  
Edge Structure ◽  
X Ray ◽  
Synchrotron Light ◽  
Evil Spirits ◽  
Eye Pattern ◽  
X Ray Absorption

The origin of Dzi beads, also called “tian zhu”, has always been a mystery. These beads come in a variety of patterns, shapes and sizes. They have cultural and heritage significance in Tibet and areas surrounding the Himalayas. The most recognized beads are those with the “eye” pattern. They are said to ward off evil spirits. Due to their reputation, the demand for Dzi beads has increased in Asia. Herein, we report a study of a Dzi bead with a three-eye pattern using X-ray diffraction (XRD), X-ray fluorescence (XRF), X-ray absorption near edge structure (XANES) and imaging techniques. This is a novel area for Dzi bead research using X-rays from a synchrotron light source to determine the chemical composition of the bead, if the pattern is natural or man-made or if the bead is genuine or a replica. These techniques revealed the bead to be composed of agate (silicon dioxide). An interesting feature on the bead’s surface was the etched rings, which were observed to contain regular copper hot spots on their circumference. Our results suggest that the Dzi bead was genuine and started out as an earth-formed agate, with the pattern crafted.

Elemental, chemical, and orientational characterization of easily damageable materials with x-ray microscopy

1995 ◽  
Vol 53 ◽  
pp. 92-93
Author(s):  
H. Ade
Keyword(s):  
Linear Dichroism ◽  
Aqueous Environment ◽  
X Rays ◽  
Edge Structure ◽  
X Ray ◽  
Elemental Sensitivity ◽  
Linearly Polarized ◽  
Synchrotron Light ◽  
X Ray Absorption

Many of the transmission x-ray microscopy developments since the late seventies, including the ones at the National Synchrotron Light Source (NSLS), were driven primarily by the potential of x-ray microscopy to image wet and unstained biological samples with low radiation dose. High image contrast between an aqueous environment and carbon based materials can be achieved with photon energies between the carbon and oxygen K absorption edges (290-540 eV). This contrast is based on differences in cross section of the elements oxygen and carbon in this energy range. Going beyond this "elemental" sensitivity, Ade et al. recently demonstrated how chemical (valence) sensitivity can be achieved via the X-ray Absorption Near Edge Structure (XANES) at the carbon K edge. In addition, linear dichroism microscopy can exploit the dependence of x-ray absorption resonances on the bond orientation relative to the linearly polarized x rays. For an application of the latter technique see A.P. Smith et al.

Material Characteristics and Electrical Modeling of Ultra Thin Copper Oxides in ULSI Application

2007 ◽  
Vol 561-565 ◽  
pp. 1225-1228
Author(s):  
Takayuki Ohba
Keyword(s):  
Diffraction Pattern ◽  
Barrier Height ◽  
Oxide Thickness ◽  
Amorphous Structure ◽  
Emission Model ◽  
X Ray Diffraction ◽  
Edge Structure ◽  
X Ray ◽  
Current Emission ◽  
X Ray Absorption

With the highest brilliance synchrotron radiation X-ray (SPring-8) and TEM observations, Cu oxides ranged 2-nm to 10-nm in thickness formed on sputtered Cu has been evaluated. For the plasma-assisted Cu oxide, weak Cu2O and/or CuO X-ray diffraction pattern is observed, while no diffraction pattern in native and thermally (170°C) grown oxides. Those native and thermal oxides show Cu2O coordination observed by XANES (X-ray Absorption Near Edge Structure) method. This suggests that Cu oxide formed at low temperatures consists of stoichiometric Cu2O in an amorphous structure. According to the Fowler-Nordheim (F-N) current emission model, the current emission taking place at Cu2O decreases with increasing of the oxide thickness and its mean barrier height (φB) in the MIM band structure. In case of current density at 106A/cm2 of 1V, it is estimated that the allowable thickness of Cu oxides is approximately 1.5-nm at 1 eV of barrier height.

scholarly journals The Atomic-Scale Interaction of Bioactive Glasses with Simulated Body Fluid

2005 ◽  
Vol 480-481 ◽  
pp. 21-26 ◽  
Author(s):  
L.J. Skipper ◽  
F.E. Sowrey ◽  
D.M. Pickup ◽  
R.J. Newport ◽  
K.O. Drake ◽  
...  
Keyword(s):  
Simulated Body Fluid ◽  
Body Fluid ◽  
Sol Gel ◽  
Atomic Scale ◽  
X Ray Diffraction ◽  
Bioactive Glasses ◽  
Edge Structure ◽  
X Ray ◽  
X Ray Absorption

The formation of a carbonate-containing hydroxyapatite, HCAp, layer on bioactive calcium silicate sol-gel glass of the formula (CaO)0.3(SiO2)0.7 has been studied in-vitro in Simulated Body Fluid (SBF). Extended X-ray Absorption Fine Structure (EXAFS), X-ray Absorption Near Edge Structure (XANES), X-ray diffraction (XRD), and solid state nuclear magnetic resonance (NMR) measurements have been performed with results showing the formation of a significantly amorphous HCAp layer after less than 5 hours in solution.

scholarly journals The nature and effects of rhodium and antimony dopants on the electronic structure of TiO2: towards design of Z-scheme photocatalysts

2016 ◽  
Vol 4 (18) ◽  
pp. 6946-6954 ◽  
Author(s):  
E. N. K. Glover ◽  
S. G. Ellington ◽  
G. Sankar ◽  
R. G. Palgrave
Keyword(s):  
Fine Structure ◽  
Photoelectron Spectroscopy ◽  
Diffuse Reflectance ◽  
Diffuse Reflectance Spectroscopy ◽  
Reflectance Spectroscopy ◽  
X Ray Diffraction ◽  
Edge Structure ◽  
X Ray ◽  
Antimony Doping ◽  
X Ray Absorption

The nature and effects of rhodium and antimony doping in TiO2 have been investigated using X-ray diffraction (XRD), X-ray Photoelectron Spectroscopy (XPS), Extended X-ray Absorption Fine Structure (EXAFS), X-ray Absorption Near Edge Structure (XANES) and diffuse reflectance spectroscopy.

Simple Preparation of Cuprous Oxide Nanoparticles for Catalysis of Azide–alkyne Cycloaddition

2018 ◽  
Vol 42 (3) ◽  
pp. 166-169 ◽  
Author(s):  
Mojtaba Amini ◽  
Sakine Ramezani ◽  
Alireza Pourvahabi Anbari ◽  
Abolghasem Beheshti ◽  
Sanjeev Gautam ◽  
...  
Keyword(s):  
Cuprous Oxide ◽  
Benzyl Chloride ◽  
Significant Loss ◽  
Oxide Nanoparticles ◽  
X Ray Diffraction ◽  
Edge Structure ◽  
X Ray ◽  
Organic Azides ◽  
Cuprous Oxide Nanoparticles ◽  
X Ray Absorption

Cuprous oxide (Cu2O) nanoparticles were prepared by two simple methods and their structural, morphological and electronic properties were investigated by X-ray diffraction analysis, X-ray absorption near-edge structure, energy dispersive X-ray analysis and scanning electron microscopy. Cuprous oxide nanoparticles efficiently catalyse 1,3-dipolar cycloaddition of a variety terminal alkynes and organic azides producing the corresponding 1,2,3-triazole derivatives in excellent yields without use of any additives. Phenylacetylene and benzyl chloride were chosen as model starting compounds for the optimisation of the reaction conditions, such as effect of solvent, reaction temperature and time of reaction in the presence of a-Cu2O nanoparticles as a catalyst. The results showed that using cuprous oxide nanoparticles (0.035 mmol) and heating at 70 °C in water, the reaction of phenylacetylene with benzyl chloride and sodium azide gave 1-benzyl-4-phenyl-1 H-1,2,3-triazole almost quantitatively in 6 h of reaction time. A study of the recyclability and reusability of the catalyst revealed that a-Cu2O could be reused at least five times without significant loss of yield.

The Structural Characterization of a Series of Uranium-containing Gadolinium Zirconates

2012 ◽  
Vol 1475 ◽  
Author(s):  
Daniel J. Gregg ◽  
Yingjie Zhang ◽  
Zhaoming Zhang ◽  
Inna Karatchevtseva ◽  
Mark G. Blackford ◽  
...  
Keyword(s):  
Raman Spectroscopy ◽  
Diffuse Reflectance ◽  
Charge Balance ◽  
X Ray Diffraction ◽  
Edge Structure ◽  
Gadolinium Zirconate ◽  
X Ray ◽  
Host Materials ◽  
X Ray Absorption

ABSTRACTA series of uranium-containing gadolinium zirconate samples have been fabricated at 1723 K in air. X-ray diffraction and Raman spectroscopy have confirmed pyrochlore or defect fluorite structures, while diffuse reflectance, X-ray absorption near edge structure and X-ray photoelectron spectroscopies indicate a predominantly U6+ oxidation state, even when Ca2+ was added to charge balance for U4+. The results demonstrate the potential of gadolinium zirconates as host materials for actinides.

Sign in / Sign up

Export Citation Format

Share Document