scholarly journals Oxygen K-edge X-ray absorption spectra of liquids with minimization of window contamination

2021 ◽  
Vol 28 (6) ◽  
Author(s):  
Linda I. Vogt ◽  
Julien J. H. Cotelesage ◽  
Charles J. Titus ◽  
Samin Sharifi ◽  
Albert E. Butterfield ◽  
...  
Keyword(s):  
Silicon Nitride ◽  
High Vacuum ◽  
Sample Holder ◽  
Simple Method ◽  
X Ray ◽  
Pure Silicon ◽  
Liquid Samples ◽  
Oxygen Contamination ◽  
Lower Oxygen ◽  
X Ray Absorption

Oxygen K-edge X-ray absorption spectroscopy is used routinely to study a range of solid materials. However, liquid samples are studied less frequently at the oxygen K-edge due to the combined challenges of high-vacuum conditions and oxygen contamination of window materials. A modular sample holder design with a twist-seal sample containment system that provides a simple method to encapsulate liquid samples under high-vacuum conditions is presented. This work shows that pure silicon nitride windows have lower oxygen contamination than both diamond- and silicon-rich nitride windows, that the levels of oxygen contamination are related to the age of the windows, and provides a protocol for minimizing the background oxygen contamination. Acid-washed 100 nm-thick silicon nitride windows were found to give good quality oxygen K-edge data on dilute liquid samples.

New Rotating Anode X-Ray Generator For XAFS Experiments

1995 ◽  
Vol 39 ◽  
pp. 149-153
Author(s):  
Kenji Sakurai
Keyword(s):  
High Vacuum ◽  
Lanthanum Hexaboride ◽  
X Rays ◽  
Tube Voltage ◽  
X Ray ◽  
Low Tube Voltage ◽  
Tube Current ◽  
Sample Position ◽  
Good Energy ◽  
X Ray Absorption

A high-power X-ray generator equipped with a lanthanum hexaboride cathode has been developed for X-ray absorption fine structure experiments. A high tube-current of more than 1,000 mA can be provided when operated at low tube-voltage of less than 20 kV. In addition, the focal width is narrow enough (less than 0.1 mm) to ensure good energy resolution. Extremely intense monochromatic X-rays (106 ∼ 107 counts/(sec.mm2) at the sample position), which are completely free from higher order harmonics and tungsten contamination lines, are available, when a Johansson-type spectrometer is employed. The filament life has been significantly prolonged by the high vacuum specification of the tube.

scholarly journals The Determination of Interfacial Structure and Phase Transitions in Al/Cu and Al/Ni Interfaces by Means of Surface Extended X-Ray Absorption Fine Structure

1991 ◽  
Vol 238 ◽  
Author(s):  
E. V. Barrera ◽  
S. M. Heald
Keyword(s):  
Fine Structure ◽  
Room Temperature ◽  
High Vacuum ◽  
Ultra High Vacuum ◽  
Interfacial Structure ◽  
Reaction Products ◽  
X Ray ◽  
Absorption Fine ◽  
Reaction Zones ◽  
X Ray Absorption

ABSTRACTSurface extended x-ray absorption fine structure (SEXAFS) was used to investigate the interfacial conditions of Al/Cu and Al/Ni shallow buried interfaces. Previous studies using glancing angle extended x-ray absorption fine structure, x-ray reflectivity, photoemission, and SEXAFS produced conflicting results as to whether or not the interfaces between Al and Cu and Al and Ni were reacted upon room temperature deposition. In this study polycrystalline bilayers of Al/Cu and Al/Ni and trilayers of Al/Cu/Al and Al/Ni/Al were deposited on tantalum foil at room temperature in ultra high vacuum and analyzed to evaluate the reactivity of these systems on a nanometer scale. It became overwhelming apparent that the interfacial phase reactions were a function of the vacuum conditions. Samples deposited with the optimum vacuum conditions showed reaction products upon deposition at room temperature which were characterized by comparisons to standards and by least squares fitting to be CuAl2 and NiAl3 respectively. The results of this study showed that the reacted zone thicknesses were readily dependent on the deposition parameters. For both Al on Cu and Al on Ni as well as the metal on Al conditions 10A reaction zones were observed. These reaction zones were smaller than that observed for bilayers of Al on Cu (30Å) and Al on Ni (60Å) where deposition rates were much higher and samples were much thicker. The reaction species are evident by SEXAFS, where the previous photoemission studies only indicated that changes had occurred. Improved vacuum conditions as compared to the earlier experiments is primarily the reason reactions on deposition were seen in this study as compared to the earlier SEXAFS studies.

Gritty Surface Sample Holder Invented To Obtain Correct X-ray Absorption Fine Structure Spectra for Concentrated Materials by Fluorescence Yield

2016 ◽  
Vol 88 (7) ◽  
pp. 3455-3458
Author(s):  
Hitoshi Abe ◽  
Yasuhiro Niwa ◽  
Masao Kimura ◽  
Youichi Murakami ◽  
Toshiharu Yokoyama ◽  
...  
Keyword(s):  
Fine Structure ◽  
Fluorescence Yield ◽  
Sample Holder ◽  
X Ray ◽  
Surface Sample ◽  
Absorption Fine ◽  
X Ray Absorption

Interrelation Between Structure and Magnetism of Ultra-Thin Mn Films Epitaxially Grown on (001) BCC Fe

1997 ◽  
Vol 475 ◽  
Author(s):  
S. Andrieu ◽  
Ph. Bauer ◽  
H. Fischer ◽  
M. Piecuch ◽  
M. Finazzi ◽  
...  
Keyword(s):  
Magnetic Properties ◽  
Electron Diffraction ◽  
Structural Transition ◽  
Magnetic Circular Dichroism ◽  
Magnetic Transition ◽  
High Vacuum ◽  
Ultra High Vacuum ◽  
X Ray ◽  
Structural And Magnetic Properties ◽  
X Ray Absorption

ABSTRACTIn this paper, the interrelation between structural and magnetic properties of ultra-thin Mn films epitaxially grown on (001) bcc Fe is studied. The Mn growth and in-plane structure were controlled by electron diffraction (RHEED). The structures of the Mn films were determined by using X-Ray absorption spectroscopy (SEXAFS). Finally, the magnetic properties were studied by using X-Ray magnetic circular dichroïsm (XMCD). All the experiments were performed under ultra-high vacuum. As shown by XMCD experiments, a magnetic transition is observed at 2 Mn monolayers. The analysis of RHEED and SEXAFS experimental results clearly demonstrates that a structural transition comes with this magnetic transition.

scholarly journals X-ray Absorption Near Edge Structures of Silicon Nitride Thin Film by Pulsed Laser Deposition

2004 ◽  
Vol 45 (7) ◽  
pp. 2039-2041 ◽  
Author(s):  
Takeo Suga ◽  
Teruyasu Mizoguchi ◽  
Masahiro Kunisu ◽  
Kazuyoshi Tatsumi ◽  
Tomoyuki Yamamoto ◽  
...  
Keyword(s):  
Thin Film ◽  
Silicon Nitride ◽  
Pulsed Laser Deposition ◽  
Pulsed Laser ◽  
Laser Deposition ◽  
X Ray ◽  
X Ray Absorption

Rapid Assay for Polystyrene Surface Oxidation

1993 ◽  
Vol 47 (10) ◽  
pp. 1609-1611 ◽  
Author(s):  
M. Bryhan ◽  
E. C. Onyiriuka ◽  
L. S. Hersh ◽  
W. Hertl
Keyword(s):  
Corona Discharge ◽  
Photoelectron Spectroscopy ◽  
High Vacuum ◽  
Surface Oxidation ◽  
Ultra High Vacuum ◽  
Surface Oxygen ◽  
Simple Method ◽  
Absorbance Measurement ◽  
X Ray ◽  
Polystyrene Surface

Polystyrene surfaces are often corona-discharge or plasma treated to oxidize the surface, which enhances the wettability. X-ray photoelectron spectroscopy (XPS), which requires time and an ultra-high vacuum, is generally used to measure this surface oxidation. A rapid, simple method for measuring polystyrene surface oxidation is described. The surface is soaked in a solution of Azure A dye, which adsorbs only to oxidized sites on the polystyrene. The excess dye is flushed away and the bound dye is desorbed with a detergent; an absorbance measurement at 635 nm is used to determine the quantity of desorbed dye. This value correlates with the polystyrene surface oxygen concentration and gives r2 = 0.93.

Simple adjustable liquid sample holder for x‐ray absorption studies

1978 ◽  
Vol 49 (11) ◽  
pp. 1559-1561 ◽  
Author(s):  
S. C. Moss ◽  
H. Metzger ◽  
M. Eisner ◽  
H. W. Huang ◽  
S. H. Hunter
Keyword(s):  
Sample Holder ◽  
Liquid Sample ◽  
X Ray ◽  
Absorption Studies ◽  
X Ray Absorption

scholarly journals FORTE – a multipurpose high-vacuum diffractometer for tender X-ray diffraction and spectroscopy at the SIRIUS beamline of Synchrotron SOLEIL

2019 ◽  
Vol 26 (4) ◽  
pp. 1374-1387
Author(s):  
G. Ciatto ◽  
N. Aubert ◽  
M. Lecroard ◽  
C. Engblom ◽  
P. Fontaine ◽  
...  
Keyword(s):  
High Vacuum ◽  
Control Architecture ◽  
Oxide Materials ◽  
Transition Elements ◽  
X Ray Diffraction ◽  
Fluorescence Detector ◽  
X Ray ◽  
Specular Reflections ◽  
X Ray Absorption ◽  
Space Volume

A new high-vacuum multipurpose diffractometer (called FORTE from the French acronyms of the project) has recently been installed at the tender/hard X-ray SIRIUS beamline of Synchrotron SOLEIL, France. The geometry chosen allows one to work either in the classical Eulerian four-circle geometry for bulk X-ray diffraction (XRD) or in the z-axis geometry for surface XRD. The diffractometer nicely fits the characteristics of the SIRIUS beamline, optimized to work in the 1.1–4.5 keV range, and allows one to perform unprecedented diffraction anomalous fine structure (DAFS) experiments in the tender X-ray region, also around non-specular reflections, covering a large reciprocal-space volume. Installation of an X-ray fluorescence detector on a dedicated flange allows simultaneous DAFS and X-ray absorption (XAS) measurements. The access to the tender X-ray region paves the way to resonant investigations around the L-edges of second-row transition elements which are constituents of functional oxide materials. It also enables access to several edges of interest for semiconductors. Finally, the control architecture based on synchronized Delta Tau units opens up exciting perspectives for improvement of the mechanical sphere of confusion.

Peak Height Approximation for X-Ray Diffracted Integrated Intensity

1975 ◽  
Vol 19 ◽  
pp. 735-767 ◽  
Author(s):  
C. P. Gazzara
Keyword(s):  
Silicon Nitride ◽  
Silicon Powder ◽  
Peak Height ◽  
Preferred Orientation ◽  
Characteristic Line ◽  
X Ray ◽  
Pure Silicon ◽  
Integrated Intensity ◽  
Cold Worked ◽  
Relationship Of

A fast X-ray diffraction powder method of quantitative analysis has been developed and demonstrated using mixtures of alpha and beta silicon nitride and silicon.An analytical procedure, assuming both Gaussian and Cauchy diffracted characteristic line distributions, was used to synthesize CuKα X-ray peaks in the 2θ range 20° to 50° with peak widths from 0.1° to 0.4° 2θ. The relationship of peak height to integrated intensity was established as a function of peak width and tested using pure silicon powder with variable receiving slit widths from 0.01° to 0.40° 2θ.Concentration calibration curves for silicon nitride and silicon were corrected for extinction and preferred orientation with statistical figures of merit to indicate the extent of preferred orientation.Preliminary results indicate that this procedure may be used for cold-worked materials.

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