Search results for "Spectroscopy"
showing 10 items of 10293 documents
Water Influences on the Copper Active Site in Hemocyanin
2010
Active metal sites play a key role in the biochemistry of oxygen transport by hemocyanins. Observing the changes in the local electronic structure of the copper sites upon oxygenation is thus essen...
X-ray Absorption under Operating Conditions for Solid-Oxide Fuel Cells Electrocatalysts: The Case of LSCF/YSZ
2019
We describe a novel electrochemical cell for X-ray absorption spectroscopy (XAS) experiments during electrical polarization suitable for high-temperature materials such as those used in solid oxide fuel cells. A half-cell LSCF/YSZ was then investigated under cathodic and anodic conditions (850 °
<title>Local structure of Ta-Re mixed oxide thin films studied by x-ray absorption spectroscopy</title>
2003
Mixed Ta-Re oxide thin films were synthesized for the first time by dc magnetron co-sputtering. Local environment around tantalum and rhenium atoms was studied by the Ta and Re L3-edges x-ray absorption spectroscopy in pure Ta2O5 and mixed Ta-Re oxide thin films (Ta:Re = 50:50, 38:62, 20:80 as determined from the ratio of the Ta-to-Re absorption edges). It was found that rhenium atoms are four-fold coordinated by oxygen atoms with R(Re-O) = 1.74 ± 0.01 Å and the mean square relative displacement (MSRD) σ2 = 0.0012 ± 0.0005 Å2. In pure Ta2O5 thin film, tantalum ions are coordinated by six oxygen atoms at R(Ta-O) = 2.02 ± 0.01 Å with the MSRD σ2 = 0.010 ± 0.001 Å2. The addition of rhenium ion…
Origin of Pressure-Induced Metallization in Cu 3 N: An X-ray Absorption Spectroscopy Study
2018
The authors are grateful to Professor Alain Polian for providing the NDAC cell.
Electroplated Indium Bumps as Thermal and Electrical Connections of NTD-Ge Sensors for the Fabrication of Microcalorimeter Arrays
2012
We are developing a method to build arrays of Ge-based microcalorimeters for soft X-rays detection using micro-photolithographic techniques. A key element of the process is the electrical and thermal connection between the germanium sensors and the interconnection electrical tracks, that lay on a substrate acting as mechanical support and thermal sink. The geometry of the sensors, that have a square base truncated pyramid shape, makes feasible a connection through indium soldering. We describe a technique, based on microlithography and electroplating, adopted to grow indium bumps of a few tens of square microns of area and several microns high on top of the contact pads patterned on the sub…
Collinear laser spectroscopy of ZrII
2003
A new technique involving collinear laser spectroscopy of ion bunches has been used to study the radio-isotopes 87,87m,88,89,89m Zr.
First on-line laser spectroscopy of radioisotopes of a refractory element
1999
The first fully on-line isotope shift measurement of a radioactive refractory element is reported. Collinear laser-induced fluorescence measurements were made on the radioactive isotopes ${}^{170,172,173,174}\mathrm{Hf}$ produced with a flux of $2--3\ifmmode\times\else\texttimes\fi{}{10}^{3}$ ions per second from an ion-guide fed isotope separator. The method may be applied to all elements and isomers with lifetimes as short as 1 ms. The systematics of the new charge radii measurements are well reproduced by theory, with the maximum deformation in the chain occurring significantly below the midshell.
Collinear fast-beam laser spectroscopy
1987
The progress in atomic and molecular spectroscopy has gone hand in hand with improvements of the resolution. Before the tunable narrow-band lasers led to the invention of Doppler-free techniques, spectral lines from cooled hollow-cathode discharges(1) had typical widths larger than 300 MHz, and high resolution was achieved only in rf spectroscopy, e.g., within hyperfine structure multiplets, by the classical techniques like atomic beam magnetic resonance,(2) optical pumρing,(3) or double resonance.(4) While the Doppler broadening $$\delta {v_D} = {v_0}{\left( {{{8kT{\rm{ }}\ln {\rm{ 2}}} \over {m{c^2}}}} \right)^{1/2}}$$ (1) is negligible for resonance frequencies v 0 in the rf regime, the …
Structure and composition of sputter-deposited nickel-tungsten oxide films
2011
Films of mixed nickel-tungsten oxide, denoted NixW1-x oxide, were prepared by reactive DC magnetron co-sputtering from metallic targets and were characterized by Rutherford backscattering spectrometry. X-ray photoelectron spectroscopy, X-ray diffractometry and Raman spectroscopy. A consistent picture of the structure and composition emerged, and at x<0.50 the films comprised a mixture of amorphous WO3 and nanosized NiWO4, at x = 0.50 the nanosized NiWO4 phase was dominating, and at x>0.50 the films contained nanosized NiO and NiWO4.
X‐Ray Photoelectron Spectroscopy
2021
X-ray photoelectron spectroscopy (XPS) is a spectroscopic technique in the family of electron spectroscopies, that is, those methods whose probe consists of electrons instead of photons. In the case of XPS, a soft, usually monochromatic X-ray causes the emission of electrons by means of the photoelectric effect. Differences in chemical potential and/or polarizability of the molecules can cause an alteration of the binding energy; in addition to photoelectrons, an ordinary XPS spectrum may also contain Auger electrons. In an XPS system, an electron gun is used to deliver a low-energy electron flux with a low current over the illuminated spot. In an XPS instrument, an ion gun may be used with…