On the wide-energy-range tuning of x-ray photoemission electron microscope optics for the observation of the photoelectrons excited by several keV x-rays

International Nuclear Information System (INIS)

Yasufuku, H.; Yoshikawa, H.; Kimura, M.; Vlaicu, A.M.; Kato, M.; Kudo, M.; Fujikata, J.; Fukushima, S.

2006-01-01

We have newly developed an x-ray photoemission electron microscope (XPEEM) which uses both soft x-rays and hard x-rays at the undulator beam line BL15XU in the synchrotron radiation (SR) facility SPring-8 to observe various practical materials. In combination with an energy analyzer and high brilliant x-ray source, the detection of high kinetic energy inner-shell photoelectrons is essential for revealing the chemical properties of specimen subsurfaces or buried interfaces, owing to long inelastic mean free path of the high kinetic energy photoelectrons. The most significant result in our design is the new combined electric and magnetic field objective lens in which the magnetic field penetrates up to the sample surface. This allows the measurement with high spatial resolution of both low intensity images of inner-shell photoelectrons with high kinetic energy and high intensity images of secondary electrons. By using the sample bias scan method, we can easily change the focus condition of the objective lens in order to allow the energy filtered imaging with photoelectrons having the kinetic energy in a wide range (1-10 000 eV). By the combination of high brilliant SR x-rays, the new objective lens, and sample bias method, our XPEEM can successfully obtain the microarea x-ray photoelectron spectra and energy filtered XPEEM images of inner-shell photoelectrons, such as Si 1s, without any surface cleaning procedure. The energy filtered XPEEM image using photoelectrons from deep inner shells, Si 1s, was obtained for the first time

Project of a photoelectron X-ray microscope on ACO storage ring

International Nuclear Information System (INIS)

Polack, F.; Lowenthal, S.

1983-01-01

A photoelectron X-ray microscope is described which is based on the principles of contact X-ray imaging and of image converters. An X-ray image is projected by a parallel X-ray beam on a thin transmission photocathode. The emitted electrons are accelerated and imaged at large magnification by an emission microscope. The instrument, which is presently under construction, is designed to provide high resolution. An electron velocity filter has been added to the usual cross-over aperture so as to reduce the spherochromatic aberration, and the cathode lens has been designed to reduce field curvature. Resolution and detection efficiency of Au and CsI cathodes are compared. The interest of the instrument for soft X-ray microscopy is briefly discussed. (orig.)

Total reflection X-ray photoelectron spectroscopy: A review

International Nuclear Information System (INIS)

Kawai, Jun

2010-01-01

Total reflection X-ray photoelectron spectroscopy (TRXPS) is reviewed and all the published papers on TRXPS until the end of 2009 are included. Special emphasis is on the historical development. Applications are also described for each report. The background reduction is the most important effect of total reflection, but interference effect, relation to inelastic mean free path, change of probing depth are also discussed.

Probing molecular orientations in thin films by x-ray photoelectron spectroscopy

Science.gov (United States)

Li, Y.; Li, P.; Lu, Z.-H.

2018-03-01

A great number of functional organic molecules in active thin-film layers of optoelectronic devices have highly asymmetric structures, such as plate-like, rod-like, etc. This makes molecular orientation an important aspect in thin-films as it can significantly affect both the optical and electrical performance of optoelectronic devices. With a combination of in-situ ultra violet photoelectron spectroscopy (UPS) and x-ray photoelectron spectroscopy (XPS) investigations for organic molecules having a broad range of structural properties, we discovered a rigid connection of core levels and frontier highest occupied molecular orbital levels at organic interfaces. This finding opens up opportunities of using X-ray photoemission spectroscopy as an alternative tool to UPS for providing an easy and unambiguous data interpretation in probing molecular orientations.

Time-resolved X-ray photoelectron spectroscopy techniques for the study of interfacial charge dynamics

Energy Technology Data Exchange (ETDEWEB)

Neppl, Stefan, E-mail: sneppl@lbl.gov; Gessner, Oliver

2015-04-15

Highlights: • Ultrafast interfacial charge transfer is probed with atomic site specificity. • Femtosecond X-ray photoelectron spectroscopy using a free electron laser. • Efficient and flexible picosecond X-ray photoelectron pump–probe scheme using synchrotron radiation. - Abstract: X-ray photoelectron spectroscopy (XPS) is one of the most powerful techniques to quantitatively analyze the chemical composition and electronic structure of surfaces and interfaces in a non-destructive fashion. Extending this technique into the time domain has the exciting potential to shed new light on electronic and chemical dynamics at surfaces by revealing transient charge configurations with element- and site-specificity. Here, we describe prospects and challenges that are associated with the implementation of picosecond and femtosecond time-resolved X-ray photoelectron spectroscopy at third-generation synchrotrons and X-ray free-electron lasers, respectively. In particular, we discuss a series of laser-pump/X-ray-probe photoemission experiments performed on semiconductor surfaces, molecule-semiconductor interfaces, and films of semiconductor nanoparticles that demonstrate the high sensitivity of time-resolved XPS to light-induced charge carrier generation, diffusion and recombination within the space charge layers of these materials. Employing the showcase example of photo-induced electronic dynamics in a dye-sensitized semiconductor system, we highlight the unique possibility to probe heterogeneous charge transfer dynamics from both sides of an interface, i.e., from the perspective of the molecular electron donor and the semiconductor acceptor, simultaneously. Such capabilities will be crucial to improve our microscopic understanding of interfacial charge redistribution and associated chemical dynamics, which are at the heart of emerging energy conversion, solar fuel generation, and energy storage technologies.

X-ray fluorescence spectrometry

International Nuclear Information System (INIS)

Ray, N.B.

1977-01-01

The principle, instrument and procedure of X-ray fluorescence spectrometry are described. It is a rapid, simple and sensitive method for the trace analysis of elements from sodium to uranium in powder, liquid or metal samples. (M.G.B.)

Probing molecular orientations in thin films by x-ray photoelectron spectroscopy

Directory of Open Access Journals (Sweden)

Y. Li

2018-03-01

Full Text Available A great number of functional organic molecules in active thin-film layers of optoelectronic devices have highly asymmetric structures, such as plate-like, rod-like, etc. This makes molecular orientation an important aspect in thin-films as it can significantly affect both the optical and electrical performance of optoelectronic devices. With a combination of in-situ ultra violet photoelectron spectroscopy (UPS and x-ray photoelectron spectroscopy (XPS investigations for organic molecules having a broad range of structural properties, we discovered a rigid connection of core levels and frontier highest occupied molecular orbital levels at organic interfaces. This finding opens up opportunities of using X-ray photoemission spectroscopy as an alternative tool to UPS for providing an easy and unambiguous data interpretation in probing molecular orientations.

X-ray spectrometry with synchrotron radiation; Roentgenspektrometrie mit Synchrotronstrahlung

Energy Technology Data Exchange (ETDEWEB)

Mueller, Matthias [Physikalisch-Technische Bundesanstalt (PTB), Berlin (Germany). Arbeitsgruppe ' Roentgen- und IR-Spektrometrie' ; Gerlach, Martin; Holfelder, Ina; Hoenicke, Philipp; Lubeck, Janin; Nutsch, Andreas; Pollakowski, Beatrix; Streeck, Cornelia; Unterumsberger, Rainer; Weser, Jan; Beckhoff, Burkhard

2014-12-15

The X-ray spectrometry of the PTB at the BESSY II storage ring with radiation in the range from 78 eV to 10.5 keV is described. After a description of the instrumentation development reference-sample free X-ray fluorescence analysis, the determination of fundamental atomic parameters, X-ray fluorescence analysis under glance-angle incidence, highly-resolving absorption spectrometry, and emission spectrometry are considered. Finally liquid cells and in-situ measurement techniques are described. (HSI)

Spectromicroscope for the PHotoelectron Imaging of Nanostructures with X-rays (SPHINX): performance in biology, medicine and geology

Energy Technology Data Exchange (ETDEWEB)

Frazer, B.H.; Girasole, Marco; Wiese, L.M.; Franz, Torsten; De Stasio, G

2004-05-15

Several X-ray PhotoElectron Emission spectroMicroscopes (X-PEEMs) exist around the world at this time. We present recent performance and resolution tests of one of them, the Spectromicroscope for PHotoelectron Imaging of Nanostructures with X-rays (SPHINX) X-PEEM, installed at the University of Wisconsin Synchrotron Radiation Center. With this state-of-the-art instrument we demonstrate chemical analysis capabilities on conducting and insulating specimens of diverse interests, and an unprecedented lateral resolution of 10 nm with monochromatic X-rays and 7.2 nm with ultraviolet illumination.

Near surface composition of some alloys by X-ray photoelectron ...

Indian Academy of Sciences (India)

0.70Ni0.30) and BiSb (Bi0.80Sb0.20, Bi0.64Sb0.34, Bi0.55Sb0.45) are determined by X-ray photoelectron spectroscopy. The stoichiometries are determined and are compared with the bulk compositions. Possible sources of systematic errors ...

The influence of temperature and X-ray dose on the deprotonation of lyophilized phenylalanine during X-ray photoelectron spectroscopy

Energy Technology Data Exchange (ETDEWEB)

Cardenas, Juan F. [Department of Chemistry, P.O. Box 1033, Blindern, N-0315 Oslo (Norway)]. E-mail: juan.cardenas@kjemi.uio.no; Groebner, Gerhard [Biophysical Chemistry, Umea University, 90187 Umea (Sweden)

2006-06-15

Lyophilized phenylalanine (LP) samples were prepared from aqueous solutions at pH {approx} 1.3 and subsequently analysed using X-ray photoelectron spectroscopy (XPS) in combination with cryogenics. When samples are measured at temperatures above {approx}0 deg. C deprotonation occurs, which gradually proceeds with X-ray bombardment. In addition, deprotonation scales linearly with the difference between the Cl and the Na concentration, which strongly suggests that HCl sublimates from the sample.

X-ray photoelectron and x-ray-induced auger electron spectroscopic data, 2

International Nuclear Information System (INIS)

Baba, Yuji; Sasaki, Teikichi

1984-04-01

The intrinsic data of the X-ray photoelectron spectra (XPS) and X-ray-induced Auger electron spectra (XAES) for 4d transition-metals and related oxides were obtained by means of a spherical electron spectrometer. The metallic surfaces were cleaned by two different metheds : mechanical filing and Ar + ion etching. In the case of the Ar + io n bombarded Y, Zr, and Nb metals, the binding energies of the core-lines and the kinetic energies of the Auger lines shift from those for the mechanically filed surfaces. The energy shifts were interpreted in terms of the ion-induced lattice distortion of the metal surfaces. The oxides examined are typical compounds such as Y 2 O 3 , ZrO 2 , Nb 2 O 5 , MoO 3 and RuO 2 . The data consists of 4 wide scans, 33 core-line spectra, 10 valence-band spectra and 12 XAES spectra. The peak positions of the core-lines and the Auger lines were summarized in 6 tables together with their chemical shifts. (author)

Annealing induced atomic rearrangements on (Ga,In) (N,As) probed by hard X-ray photoelectron spectroscopy and X-ray absorption fine structure.

Science.gov (United States)

Ishikawa, Fumitaro; Higashi, Kotaro; Fuyuno, Satoshi; Morifuji, Masato; Kondow, Masahiko; Trampert, Achim

2018-04-13

We study the effects of annealing on (Ga 0.64 ,In 0.36 ) (N 0.045 ,As 0.955 ) using hard X-ray photoelectron spectroscopy and X-ray absorption fine structure measurements. We observed surface oxidation and termination of the N-As bond defects caused by the annealing process. Specifically, we observed a characteristic chemical shift towards lower binding energies in the photoelectron spectra related to In. This phenomenon appears to be caused by the atomic arrangement, which produces increased In-N bond configurations within the matrix, as indicated by the X-ray absorption fine structure measurements. The reduction in the binding energies of group-III In, which occurs concomitantly with the atomic rearrangements of the matrix, causes the differences in the electronic properties of the system before and after annealing.

A new endstation at the Swiss Light Source for ultraviolet photoelectron spectroscopy, X-ray photoelectron spectroscopy, and X-ray absorption spectroscopy measurements of liquid solutions

International Nuclear Information System (INIS)

Brown, Matthew A.; Redondo, Amaia Beloqui; Duyckaerts, Nicolas; Mächler, Jean-Pierre; Jordan, Inga; Wörner, Hans Jakob; Lee, Ming-Tao; Ammann, Markus; Nolting, Frithjof; Kleibert, Armin; Huthwelker, Thomas; Birrer, Mario; Honegger, Juri; Wetter, Reto; Bokhoven, Jeroen A. van

2013-01-01

A new liquid microjet endstation designed for ultraviolet (UPS) and X-ray (XPS) photoelectron, and partial electron yield X-ray absorption (XAS) spectroscopies at the Swiss Light Source is presented. The new endstation, which is based on a Scienta HiPP-2 R4000 electron spectrometer, is the first liquid microjet endstation capable of operating in vacuum and in ambient pressures up to the equilibrium vapor pressure of liquid water at room temperature. In addition, the Scienta HiPP-2 R4000 energy analyzer of this new endstation allows for XPS measurements up to 7000 eV electron kinetic energy that will enable electronic structure measurements of bulk solutions and buried interfaces from liquid microjet samples. The endstation is designed to operate at the soft X-ray SIM beamline and at the tender X-ray Phoenix beamline. The endstation can also be operated using a Scienta 5 K ultraviolet helium lamp for dedicated UPS measurements at the vapor-liquid interface using either He I or He II α lines. The design concept, first results from UPS, soft X-ray XPS, and partial electron yield XAS measurements, and an outlook to the potential of this endstation are presented

A new endstation at the Swiss Light Source for ultraviolet photoelectron spectroscopy, X-ray photoelectron spectroscopy, and X-ray absorption spectroscopy measurements of liquid solutions.

Science.gov (United States)

Brown, Matthew A; Redondo, Amaia Beloqui; Jordan, Inga; Duyckaerts, Nicolas; Lee, Ming-Tao; Ammann, Markus; Nolting, Frithjof; Kleibert, Armin; Huthwelker, Thomas; Müächler, Jean-Pierre; Birrer, Mario; Honegger, Juri; Wetter, Reto; Wörner, Hans Jakob; van Bokhoven, Jeroen A

2013-07-01

A new liquid microjet endstation designed for ultraviolet (UPS) and X-ray (XPS) photoelectron, and partial electron yield X-ray absorption (XAS) spectroscopies at the Swiss Light Source is presented. The new endstation, which is based on a Scienta HiPP-2 R4000 electron spectrometer, is the first liquid microjet endstation capable of operating in vacuum and in ambient pressures up to the equilibrium vapor pressure of liquid water at room temperature. In addition, the Scienta HiPP-2 R4000 energy analyzer of this new endstation allows for XPS measurements up to 7000 eV electron kinetic energy that will enable electronic structure measurements of bulk solutions and buried interfaces from liquid microjet samples. The endstation is designed to operate at the soft X-ray SIM beamline and at the tender X-ray Phoenix beamline. The endstation can also be operated using a Scienta 5 K ultraviolet helium lamp for dedicated UPS measurements at the vapor-liquid interface using either He I or He II α lines. The design concept, first results from UPS, soft X-ray XPS, and partial electron yield XAS measurements, and an outlook to the potential of this endstation are presented.

A new endstation at the Swiss Light Source for ultraviolet photoelectron spectroscopy, X-ray photoelectron spectroscopy, and X-ray absorption spectroscopy measurements of liquid solutions

Energy Technology Data Exchange (ETDEWEB)

Brown, Matthew A.; Redondo, Amaia Beloqui; Duyckaerts, Nicolas; Mächler, Jean-Pierre [Institute for Chemical and Bioengineering, ETH Zürich, CH-8093 Zürich (Switzerland); Jordan, Inga; Wörner, Hans Jakob [Laboratory of Physical Chemistry, ETH Zürich, CH-8093 Zürich (Switzerland); Lee, Ming-Tao; Ammann, Markus; Nolting, Frithjof; Kleibert, Armin; Huthwelker, Thomas; Birrer, Mario; Honegger, Juri; Wetter, Reto [Paul Scherrer Institute, CH-5232 Villigen PSI (Switzerland); Bokhoven, Jeroen A. van [Institute for Chemical and Bioengineering, ETH Zürich, CH-8093 Zürich (Switzerland); Paul Scherrer Institute, CH-5232 Villigen PSI (Switzerland)

2013-07-15

A new liquid microjet endstation designed for ultraviolet (UPS) and X-ray (XPS) photoelectron, and partial electron yield X-ray absorption (XAS) spectroscopies at the Swiss Light Source is presented. The new endstation, which is based on a Scienta HiPP-2 R4000 electron spectrometer, is the first liquid microjet endstation capable of operating in vacuum and in ambient pressures up to the equilibrium vapor pressure of liquid water at room temperature. In addition, the Scienta HiPP-2 R4000 energy analyzer of this new endstation allows for XPS measurements up to 7000 eV electron kinetic energy that will enable electronic structure measurements of bulk solutions and buried interfaces from liquid microjet samples. The endstation is designed to operate at the soft X-ray SIM beamline and at the tender X-ray Phoenix beamline. The endstation can also be operated using a Scienta 5 K ultraviolet helium lamp for dedicated UPS measurements at the vapor-liquid interface using either He I or He II α lines. The design concept, first results from UPS, soft X-ray XPS, and partial electron yield XAS measurements, and an outlook to the potential of this endstation are presented.

Ultrafast soft X-ray photoelectron spectroscopy at liquid water microjets.

Science.gov (United States)

Faubel, M; Siefermann, K R; Liu, Y; Abel, B

2012-01-17

Since the pioneering work of Kai Siegbahn, electron spectroscopy for chemical analysis (ESCA) has been developed into an indispensable analytical technique for surface science. The value of this powerful method of photoelectron spectroscopy (PES, also termed photoemission spectroscopy) and Siegbahn's contributions were recognized in the 1981 Nobel Prize in Physics. The need for high vacuum, however, originally prohibited PES of volatile liquids, and only allowed for investigation of low-vapor-pressure molecules attached to a surface (or close to a surface) or liquid films of low volatility. Only with the invention of liquid beams of volatile liquids compatible with high-vacuum conditions was PES from liquid surfaces under vacuum made feasible. Because of the ubiquity of water interfaces in nature, the liquid water-vacuum interface became a most attractive research topic, particularly over the past 10 years. PES studies of these important aqueous interfaces remained significantly challenging because of the need to develop high-pressure PES methods. For decades, ESCA or PES (termed XPS, for X-ray photoelectron spectroscopy, in the case of soft X-ray photons) was restricted to conventional laboratory X-ray sources or beamlines in synchrotron facilities. This approach enabled frequency domain measurements, but with poor time resolution. Indirect access to time-resolved processes in the condensed phase was only achieved if line-widths could be analyzed or if processes could be related to a fast clock, that is, reference processes that are fast enough and are also well understood in the condensed phase. Just recently, the emergence of high harmonic light sources, providing short-wavelength radiation in ultrashort light pulses, added the dimension of time to the classical ESCA or XPS technique and opened the door to (soft) X-ray photoelectron spectroscopy with ultrahigh time resolution. The combination of high harmonic light sources (providing radiation with laserlike

X-ray fluorescence spectrometry

International Nuclear Information System (INIS)

Vries, J.L. de.

1976-01-01

The seventh edition of Philips' Review of Literature on x-ray fluorescence spectrometry starts with a list of conference proceedings on the subject, organised by the Philips organisation at regular intervals in various European countries. It is followed by a list of bulletins. The bibliography is subdivided according to spectra, equipment, applications and absorption analysis

Experiment study on the thick GEM-like multiplier for X-ray photoelectrons energy deposition gaining

International Nuclear Information System (INIS)

Zhu Pengfei; Ye Yan; Long Yan; Cao Ningxiang; Jia Xing; Li Jianfeng

2009-01-01

The GEM is a novel detector with high gain,high time and location resolution. Imitating the structure of the GEM, a thick GEM-like multiplier which has the similar function with that of the GEM is designed and manufactured. The characteristics of the thick GEM-like multiplier increasing electron energy deposition in absorbing medium has been experimentally studied. The results indicate that the energy deposition gain of x-ray photoelectron in medium is apparent, and the maximum energy deposition can increase by more than 40%. Some suggestions of further increasing the energy deposition are given, and the future application of the way of increasing the x-ray photoelectron energy deposition by the thick GEM-like multiplier in hard x-ray imaging is prospected. (authors)

Angle-resolved X-ray fluorescence spectrometry using synchrotron radiation at ELSA

International Nuclear Information System (INIS)

Schmitt, W.; Rothe, J.; Hormes, J.; Gries, W.H.

1994-01-01

Measurements on the centroid depth of ion-implanted phosphorus-in-silicon specimen by the method of angle-resolved, self-ratio X-ray fluorescence spectrometry (AR/SR/XFS) have been carried out using 'white' synchrotron radiation (SR). The measurements were performed using a modified wavelength-dispersive fluorescence spectrometer. Problems due to the use of SR, like carbonaceous specimen contamination and sample heating were overcome by flooding the specimen chamber with helium and by pre-absorbing the non-exciting parts of the incident SR with suitable filters, respectively. The decaying primary intensity was monitored by measuring the compensation current of the photoelectrons emitted from a tungsten wire stretched across the primary beam. Results have been obtained for specimen with dose density levels of 10 16 cm -2 and 3x10 15 cm -2 . (orig.)

Bonding in inorganic compounds: a study by x-ray photoelectron spectroscopy

International Nuclear Information System (INIS)

Avanzino, S.C.

1978-10-01

Core electron binding energies were measured for a variety of inorganic and organometallic compounds using gas-phase X-ray photoelectron spectroscopy (XPS). The atomic charge distributions in these molecules are deduced from the binding energies, often leading to a better understanding of the bonding in these compounds. The XPS spectra of fifteen volatile tin compounds were recorded. The data suggest that the metal d orbitals are not significantly involved in the bonding. The oxygen ls XPS spectra of gaseous CH 3 Mn(CO) 5 , [π-C 5 H 5 Fe(CO) 2 ] 2 , and Co 4 (CO) 12 can be readily resolved into separate peaks due to bridging and terminal carbonyl groups. The C ls spectrum of Fe(CO) 5 consists of a single symmetric peak. The carbonyl ligand core binding energies of transition-metal carbonyl complexes are sensitive to differences in the metal-to-CO ligand bonding. Both C ls and O ls carbonyl binding energies correlate well with average C-O stretching force constants or average C-O stretching frequencies. The metal and carbonyl binding energies in a series of pentacarbonylmanganese complexes LMn(CO) 5 are a good measure of the relative electronegativities of the ligands L. High-quality X-ray photoelectron spectra have been obtained for compounds dissolved in glycerin solutions, and aqueous solutions were converted into glycerin solutions which gave good XRSspectra of the solutes. The technique appears promising as a future analytical application of X-ray photoelectron spectroscopy. The shifts in the binding energies of oxygen, chlorine, and carbon atoms in some isoelectronic isostructural compounds can be explained in terms of simple trends in atomic charges

X-ray Photoelectron Spectroscopy study of CaV1-xMoxO3-δ

Science.gov (United States)

Belyakov, S. A.; Kuznetsov, M. V.; Shkerin, S. N.

2018-06-01

An investigation was carried out on perovskite-based derivatives of CaV1-xMoxO3-δ using X-ray Photoelectron Spectroscopy (XPS). According to the XRD pattern, the area of homogeneity covers the region from x = 0 to x = 0.6. Wide XPS-peaks of Ca, V, Mo and O are observed, signalling that elements are presented in multiple states. A model for explaining the large chemical shifts of XPS peaks due to different charging effects on different parts of the sample surface is proposed.

X-ray photoelectron spectra of γ-irradiated perfluorobenzene

International Nuclear Information System (INIS)

Sunder, S.; Sagert, N.H.; Wood, D.D.; Miller, N.H.

1990-01-01

The effect of γ-radiolysis on perfluorobenzene (PFB) was investigated using low-temperature X-ray photoelectron spectroscopy (XPS). PFB was irradiated in fluorine-passivated nickel cells using Co 60 γ-rays in an Atomic Energy of Canada Limited Gammacell at a dose rate of about 2.6 Gy·s -1 and for a total dose of about 50 kGy. The γ-radiolysis of PFB not only results in cross-linkage but also in the formation of saturated carbon centers in the PFB, as indicated by the presence of CF 2 and CF 3 groups. The relative abundance of CF, CF 2 and CF 3 groups, in the irradiated PFB, was estimated to be about 86, 9 and 5%, respectively

Diagnostic X-ray spectrometry using a commercial CdZnTe detector

International Nuclear Information System (INIS)

Becker, P.H.B.

1998-01-01

X ray spectrometry using Ge or Si detectors is an established tool to measure characterization parameters of X-ray beams. This work describes how a commercial CdZnTe was used to perform diagnostic X-ray spectrometry. Spectra were measured for two X-ray machines and compared with similar data found in the literature with an agreement of 2% rms

X-ray spectrometry for preventive conservation of cultural heritage

Indian Academy of Sciences (India)

Analytical chemistry does play a key role in the chemical characterization of the environment and it appears that X-ray spectrometry, in its many forms, is one of the most relevant analytical techniques in preventive conservation, as it is in cultural heritage research in general. X-ray spectrometry has indeed been the method ...

Photoelectron and x-ray holography by contrast: enhancing image quality and dimensionality

Energy Technology Data Exchange (ETDEWEB)

Fadley, C.S.; Zhao, L. [Materials Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, CA (United States); Department of Physics, University of California, Davis, CA (United States); Hove, M.A. van [Materials Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, CA (United States); Department of Physics, University of California, Davis, CA (United States); Advanced Light Source, Lawrence Berkeley National Laboratory, Berkeley, CA (United States); Kaduwela, A.; Marchesini, S. [Materials Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, CA (United States); Omori, S. [Materials Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, CA (United States); Institute of Industrial Science, University of Tokyo, Tokyo (Japan); Sony Corporation Semiconductor Network Company, Asahi-cho, Atsugi, Kanagawa (Japan)

2001-11-26

Three forms of electron or x-ray holography 'by contrast' are discussed: they all exploit small changes in diffraction conditions to improve image quality and/or extract additional information. Spin-polarized photoelectron holography subtracts spin-down from spin-up holograms so as to image the relative orientations of atomic magnetic moments around an emitter atom. Differential photoelectron holography subtracts holograms taken at slightly different energies so as to overcome the forward-scattering problem that normally degrades the three-dimensional imaging of atoms, particularly for emitter atoms that are part of a bulk substrate environment. Resonant x-ray fluorescence holography also subtracts holograms at slightly different energies, these being chosen above and below an absorption edge of a constituent atom, thus allowing the selective imaging of that type of atom, or what has been referred to as imaging 'in true colour'. (author)

GaN quantum dot polarity determination by X-ray photoelectron diffraction

Czech Academy of Sciences Publication Activity Database

Romanyuk, Olexandr; Bartoš, Igor; Brault, J.; De Mierry, P.; Paskova, T.; Jiříček, Petr

2016-01-01

Roč. 389, Dec (2016), s. 1156-1160 ISSN 0169-4332 R&D Projects: GA ČR GA15-01687S; GA MŠk LM2015088 Institutional support: RVO:68378271 Keywords : GaN * semipolar GaN * quantum dots * X-ray photoelectron diffraction * surface polarity Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 3.387, year: 2016

Quantitative spectromicroscopy from inelastically scattered photoelectrons in the hard X-ray range

Energy Technology Data Exchange (ETDEWEB)

Renault, O., E-mail: olivier.renault@cea.fr; Zborowski, C.; Risterucci, P. [Univ. Grenoble Alpes, F-38000 Grenoble, France and CEA, LETI, MINATEC Campus, F-38054 Grenoble (France); Wiemann, C.; Schneider, C. M. [Peter Grünberg Institute (PGI-6) and JARA-FIT, Research Center Jülich, D-52425 Jülich (Germany); Grenet, G. [Institut des Nanotechnologies de Lyon, Ecole Centrale, 69134 Ecully Cedex (France); Tougaard, S. [Department of Physics, Chemistry and Pharmacy, University of Southern Denmark, DK-5230 Odense M (Denmark)

2016-07-04

We demonstrate quantitative, highly bulk-sensitive x-ray photoelectron emission microscopy by analysis of inelastically scattered photoelectrons in the hard X-ray range, enabling elemental depth distribution analysis in deeply buried layers. We show results on patterned structures used in electrical testing of high electron mobility power transistor devices with an epitaxial Al{sub 0.25}Ga{sub 0.75}N channel and a Ti/Al metal contact. From the image series taken over an energy range of up to 120 eV in the Ti 1s loss feature region and over a typical 100 μm field of view, one can accurately retrieve, using background analysis together with an optimized scattering cross-section, the Ti depth distribution from 14 nm up to 25 nm below the surface. The method paves the way to multi-elemental, bulk-sensitive 3D imaging and investigation of phenomena at deeply buried interfaces and microscopic scales by photoemission.

X-ray photoelectron spectroscopy study on Ba1-xEuxTiO3

International Nuclear Information System (INIS)

Lu, D.-Y.; Sugano, Mikio; Sun Xiuyun; Su Wenhui

2005-01-01

X-ray photoelectron spectroscopy is employed to study inner-shell core-level binding energies Eu 4d, Ti 2p and O 1s, Ba 3d for new single-phase Ba 1-x Eu x TiO 3 (0.1 ≤ x ≤ 0.4) samples prepared by solid state reaction at 4.0 GPa and 1090 deg. C. The peak positions of binding energies determined by linear background subtraction and Gaussian fit are presented. XPS analysis indicates that the mixed-valent Eu 3+ /Eu 2+ ions at A-site and Ti 4+ /Ti 3+ ions at B-site coexisted in the Ba 1-x Eu x TiO 3 powder surface, and the amount of Eu 2+ ions is equal to Eu 3+ ions

Electronic structure simulation of chromium aluminum oxynitride by discrete variational-X{alpha} method and X-ray photoelectron spectroscopy

Energy Technology Data Exchange (ETDEWEB)

Choi, Youngmin; Chang, Hyunju; Lee, Jae Do [Korea Research Inst. of Chemical Technology, Taejon (Korea); Kim, Eunah; No, Kwangsoo [Korea Advanced Inst. of Science and Technology, Taejon (Korea)

2002-09-01

We use a first-principles discrete variational (DV)-X{alpha} method to investigate the electronic structure of chromium aluminum oxynitride. When nitrogen is substituted for oxygen in the Cr-Al-O system, the N2p level appears in the energy range between O2p and Cr3d levels. Consequently, the valence band of chromium aluminum oxynitride becomes broader and the band gap becomes smaller than that of chromium aluminum oxide, which is consistent with the photoelectron spectra for the valence band using X-ray photoelectron spectroscopy (XPS) and ultraviolet photoelectron spectroscopy (UPS). We expect that this valence band structure of chromium aluminum oxynitride will modify the transmittance slope which is a requirement for photomask application. (author)

Complete k-space visualization of x-ray photoelectron diffraction

International Nuclear Information System (INIS)

Denlinger, J.D.; Lawrence Berkeley Lab., CA; Rotenberg, E.; Lawrence Berkeley Lab., CA; Kevan, S.D.; Tonner, B.P.

1996-01-01

A highly detailed x-ray photoelectron diffraction data set has been acquired for crystalline Cu(001). The data set for bulk Cu 3p emission encompasses a large k-space volume (k = 3--10 angstrom -1 ) with sufficient energy and angular sampling to monitor the continuous variation of diffraction intensities. The evolution of back-scattered intensity oscillations is visualized by energy and angular slices of this volume data set. Large diffraction data sets such as this will provide rigorous experimental tests of real-space reconstruction algorithms and multiple-scattering simulations

Passivity of 316L stainless steel in borate buffer solution studied by Mott-Schottky analysis, atomic absorption spectrometry and X-ray photoelectron spectroscopy

International Nuclear Information System (INIS)

Feng Zhicao; Cheng Xuequn; Dong Chaofang; Xu Lin; Li Xiaogang

2010-01-01

Research highlights: → The polarization curve of 316L SS possesses five turning potentials in passive region. → Films formed at turning potentials perform different electrochemical and semiconductor properties. → Dissolutions and regenerations of passive film at turning potentials are obtained by AAS and XPS. → Turning potentials appearing in passive region are ascribed to the changes of the compositions of the passive films. - Abstract: The passivity of 316L stainless steel in borate buffer solution has been investigated by Mott-Schottky, atomic absorption spectrometry (AAS) and X-ray photoelectron spectroscopy (XPS). The results indicate that the polarization curve in the passive region possesses several turning potentials (0 V SCE , 0.2 V SCE , 0.4 V SCE , 0.6 V SCE and 0.85 V SCE ). The passive films formed at turning potentials perform different electrochemical and semiconductor properties. Further, the compositions of the passive films formed at turning potentials are investigated. The results reasonably explain why these potentials appear in the passive region and why specimens perform different properties at turning potentials.

A lab-based ambient pressure x-ray photoelectron spectrometer with exchangeable analysis chambers

Energy Technology Data Exchange (ETDEWEB)

Newberg, John T., E-mail: jnewberg@udel.edu; Arble, Chris; Goodwin, Chris; Khalifa, Yehia; Broderick, Alicia [Department of Chemistry & Biochemistry, University of Delaware, Newark, Delaware 19716 (United States); Åhlund, John [Scienta AB, Box 15120, 750 15 Uppsala (Sweden)

2015-08-15

Ambient pressure X-ray photoelectron spectroscopy (APXPS) is a powerful spectroscopy tool that is inherently surface sensitive, elemental, and chemical specific, with the ability to probe sample surfaces under Torr level pressures. Herein, we describe the design of a new lab-based APXPS system with the ability to swap small volume analysis chambers. Ag 3d(5/2) analyses of a silver foil were carried out at room temperature to determine the optimal sample-to-aperture distance, x-ray photoelectron spectroscopy analysis spot size, relative peak intensities, and peak full width at half maximum of three different electrostatic lens modes: acceleration, transmission, and angular. Ag 3d(5/2) peak areas, differential pumping pressures, and pump performance were assessed under varying N{sub 2}(g) analysis chamber pressures up to 20 Torr. The commissioning of this instrument allows for the investigation of molecular level interfacial processes under ambient vapor conditions in energy and environmental research.

X-ray fluorescence imaging with polycapillary X-ray optics

International Nuclear Information System (INIS)

Yonehara, Tasuku; Yamaguchi, Makoto; Tsuji, Kouichi

2010-01-01

X-ray fluorescence spectrometry imaging is a powerful tool to provide information about the chemical composition and elemental distribution of a specimen. X-ray fluorescence spectrometry images were conventionally obtained by using a μ-X-ray fluorescence spectrometry spectrometer, which requires scanning a sample. Faster X-ray fluorescence spectrometry imaging would be achieved by eliminating the process of sample scanning. Thus, we developed an X-ray fluorescence spectrometry imaging instrument without sample scanning by using polycapillary X-ray optics, which had energy filter characteristics caused by the energy dependence of the total reflection phenomenon. In the present paper, we show that two independent straight polycapillary X-ray optics could be used as an energy filter of X-rays for X-ray fluorescence. Only low energy X-rays were detected when the angle between the two optical axes was increased slightly. Energy-selective X-ray fluorescence spectrometry images with projection mode were taken by using an X-ray CCD camera equipped with two polycapillary optics. It was shown that Fe Kα (6.40 keV) and Cu Kα (8.04 keV) could be discriminated for Fe and Cu foils.

Quadrupole effects in core and valence photoelectron emission from crystalline germanium measured via a spatially modulated x-ray interference field

International Nuclear Information System (INIS)

Nelson, E.J.; Woicik, J.C.; Pianetta, P.; Vartanyants, I.A.; Cooper, J.W.

2002-01-01

Near a crystal x-ray Bragg reflection, the incident and reflected x-ray beams that travel with opposite wave vectors create an x-ray standing-wave (XSW) interference field. The quadrupole (and higher order nondipole) contributions to the photoelectron emission matrix element differ for these two beams due to their different wave vectors. By monitoring the angle-resolved photoelectron yield as a function of photon energy near the (11-1) Bragg back-reflection condition of crystalline Ge, we measure the contribution of nondipole effects to Ge 3p, Ge 3d, and Ge valence-band (4s and 4p) XSW photoelectron emission. Significant changes due to nondipole emission are measured in both the apparent amplitude and phase of the Ge structure factor relative to the true Ge atomic distribution, and compared to theory

Time-resolved x-ray laser induced photoelectron spectroscopy of isochoric heated copper

International Nuclear Information System (INIS)

Nelson, A.J.; Dunn, J.; Hunter, J.; Widmann, K.

2005-01-01

Time-resolved x-ray photoelectron spectroscopy is used to probe the nonsteady-state evolution of the valence band electronic structure of laser heated ultrathin (50 nm) copper. A metastable phase is studied using a 527 nm wavelength 400 fs laser pulse containing 0.1-2.5 mJ laser energy focused in a large 500x700 μm 2 spot to create heated conditions of 0.07-1.8x10 12 W cm -2 intensity. Valence band photoemission spectra are presented showing the changing occupancy of the Cu 3d level with heating are presented. These picosecond x-ray laser induced time-resolved photoemission spectra of laser-heated ultrathin Cu foil show dynamic changes in the electronic structure. The ultrafast nature of this technique lends itself to true single-state measurements of shocked and heated materials

X-ray photoelectron spectroscopy study of the functionalization of carbon metal-containing nanotubes with phosphorus atoms

International Nuclear Information System (INIS)

Shabanova, I.N.; Terebova, N.S.

2013-01-01

Highlights: •Carbon metal-containing nanotubes (Me–Cu, Ni, Fe) were functionalized with chemical groups containing different concentrations of phosphorous. •The C1s and Me3s spectra were measured by the X-ray photoelectron spectroscopy method. •The values of the atomic magnetic moment of the carbon metal-containing nanotubes were determined. -- Abstract: In the present paper, carbon metal-containing (Me: Cu, Ni, Fe) nanotubes functionalized with phosphorus atoms (ammonium polyphosphate) were studied by X-ray photoelectron spectroscopy (XPS) on an X-ray electron magnetic spectrometer. It is found that the functionalization leads to the change of the metal atomic magnetic moment, i.e. the value of the atomic magnetic moment in the functionalized carbon metal-containing (Cu, Ni, Fe) nanotubes increases and is higher than that in pristine nanotubes. It is shown that the covalent bond of Me and P atoms is formed. This leads to an increase in the activity of the nanostructure surface which is necessary for the modification of materials

X-ray photoelectron spectroscopic study of catalyst based zinc oxide thin films

International Nuclear Information System (INIS)

Shinde, S.S.; Rajpure, K.Y.

2011-01-01

Research highlights: → The two step approach for quantitative XPS analysis of ZnO films has been reported. → Surface composition and chemical states of F and In/ZnO catalysts have been studied. → The chemical shifts and Auger parameter have been investigated. - Abstract: X-ray photoelectron spectroscopy (XPS) is a powerful tool for surface and interface analysis, providing an elemental composition of surfaces and the local chemical environment of adsorbed species. The surface composition and chemical states of the F/ZnO and In/ZnO catalysts deposited using spray technique have been studied by high resolution and high sensitivity X-ray photoelectron spectroscopy. A hybrid multiline method is proposed for quantitative XPS analysis that combines the first principles approach with the experimental determination of overall response function. The chemical shifts of XPS core lines for Zn (2P 3/2 , F 1s and In 3d) and Auger parameter for zinc (β Zn = 2012.6, 2011.48 eV for F/ZnO and In/ZnO, respectively) have been calculated. The results have been used to determine the bond iconicity (0.55).

X-ray photoelectron spectroscopy in North America - the early years

International Nuclear Information System (INIS)

Shirley, D.A.; Fadley, C.S.

2004-01-01

In this paper, we present a brief overview of the beginning years of X-ray photoelectron spectroscopy in the USA, with particular emphasis on activities in Berkeley with which we are more familiar, but comments also on some other significant developments during this period. With some arbitrariness, we have limited ourselves to topics that were at least underway by the time of the first conference in this series in 1971, and thus finally published by 1973 or so. Some key first results or analyses are illuminated with figures from the literature

Use of X-Ray Fluorescence Spectrometry to Determine Trace ...

African Journals Online (AJOL)

This paper deals with application of X-ray fluorescence spectrometry for the detection of trace elements in graphic. An X-ray spectrometer was constructed and used to carry out measurements on graphite spheres impregnated with different chemical elements. The intensities of the lines of these trace elements, as function of ...

X-ray photoelectron spectroscopy study of the metal/cermet interface

International Nuclear Information System (INIS)

Lu Hua; Shen Dianhong; Xue Qikun

2001-01-01

Interfacial reactions between aluminium and polycrystalline cermet TiC 0.6 were investigated using x-ray photo-electron spectroscopy, Auger electron spectroscopy and x-ray diffraction. It was found that titanium exists in two chemical states. The carbide and oxide of titanium can be detected simultaneously, and the atomic ratio of Ti:C:O is 5:3:2. This suggests that TiC 0.6 is a Ti-oxycarbide or oxygenated Tic composite: Ti 5 C 3 O 2 (TiO 2 + 4TiC 0.75 ). When Al is deposited in vacuum on the Ti-oxycarbide surface, the active Al atoms react chemically only with TiO 2 at room temperature, but not with TiC 0.75 in Ti-oxycarbide. The reaction products are Al 2 O 3 and the intermetallic compound Al 3 Ti. Annealing the Al/TiC 0.6 interface at 750 degree C, Al reacts also with TiC 0.75 to form a brittle Al 4 C 3 phase

Adsorbate induced surface alloy formation investigated by near ambient pressure X-ray photoelectron spectroscopy

DEFF Research Database (Denmark)

Nierhoff, Anders Ulrik Fregerslev; Conradsen, Christian Nagstrup; McCarthy, David Norman

2014-01-01

for engineering of more active or selective catalyst materials. Dynamical surface changes on alloy surfaces due to the adsorption of reactants in high gas pressures are challenging to investigate using standard characterization tools. Here we apply synchrotron illuminated near ambient pressure X-ray photoelectron...

Dealloying of Cu{sub x}Au studied by hard X-ray photoelectron spectroscopy

Energy Technology Data Exchange (ETDEWEB)

Rajput, Parasmani, E-mail: parasmani.rajput@northwestern.edu [European Synchrotron Radiation Facility, 6 rue Jules Horowitz, F-38043 Grenoble (France); Gupta, Ajay [UGC-DAE Consortium for Scientific Research, University Campus, Khandwa Road, Indore 452 017 (India); Detlefs, Blanka [European Synchrotron Radiation Facility, 6 rue Jules Horowitz, F-38043 Grenoble (France); Kolb, Dieter M. [Institute for Electrochemistry, University of Ulm, D-89069 Ulm (Germany); Potdar, Satish [UGC-DAE Consortium for Scientific Research, University Campus, Khandwa Road, Indore 452 017 (India); Zegenhagen, Jörg [European Synchrotron Radiation Facility, 6 rue Jules Horowitz, F-38043 Grenoble (France)

2013-10-15

Highlights: ► The shift in binding energy of Cu and Au lines in CuAu alloys is opposite to expected from the nobility of the elements. ► The magnitude of the chemical shifts of the metal lines in CuAu alloys is strongly influenced by finite size effects and disorder. ► Cu 3s and/or Au 4f cross-sections are not well described by theory (Scofield). The Cu 3s photoabsorption cross-section seems to be strongly overestimated. ► We find/confirm that (CuAu) dealloying proceeds into depth like a spinodal decomposition. -- Abstract: We studied pristine and leached ultra-thin Cu{sub x}Au (x ≈ 4) films by hard X-ray photoelectron spectroscopy. The Au 4f and Cu 3s core levels show a shift in binding energy which is opposite to expected from the nobility of the elements, which is explained by charge transfer involving differently screening s and d valence levels of the elements [W. Eberhardt, S.C. Wu, R. Garrett, D. Sondericker, F. Jona, Phys. Rev. B 31 (1985) 8285]. The magnitude of the chemical shifts of the metal lines is strongly influenced by the finite size and disorder of the films. Angular dependent photoelectron emission allowed to assess the alloy composition as a function of depth larger than 5 nm. The potential controlled dealloying proceeds into depth like a spinodal decomposition with Cu going into solution and the remaining Au accumulating in the surface region. The compositional gradient did not lead to a significant broadening of the metal photoelectron lines suggesting a non-local screening mechanism.

Determination of electronic and atomic properties of surface, bulk and buried interfaces: Simultaneous combination of hard X-ray photoelectron spectroscopy and X-ray diffraction

Energy Technology Data Exchange (ETDEWEB)

Rubio-Zuazo, J., E-mail: rubio@esrf.fr [SpLine, Spanish CRG BM25 Beamline at the ESRF, ESRF, B.P. 220, F-38043 Grenoble (France); Instituto de Ciencia de Materiales de Madrid, ICMM, CSIC, Cantoblanco, E-28049 Madrid (Spain); Castro, G.R. [SpLine, Spanish CRG BM25 Beamline at the ESRF, ESRF, B.P. 220, F-38043 Grenoble (France); Instituto de Ciencia de Materiales de Madrid, ICMM, CSIC, Cantoblanco, E-28049 Madrid (Spain)

2013-10-15

Highlights: •We have developed a novel and exceptional tool for non-destructive characterization of bulk and buried interfaces that combine XRD and HAXPES. •We studied the correlation between the atomic, electronic and transport properties of oxygen deficient manganite thin films. •The diffraction data showed a cooperative tilt of the MnO{sub 6} block along the out-of-plane direction. •We shown the absence of the conventional basal plane rotation for the oxygen deficient samples. -- Abstract: Hard X-ray photoelectron spectroscopy (HAXPES) is a powerful novel emerging technique for bulk compositional, chemical and electronic properties determination in a non-destructive way. It benefits from the exceptionally large escape depth of high kinetic energy photoelectrons enabling the study of bulk and buried interfaces up to several tens of nanometres depth. Its advantage over conventional XPS is based on the long mean free path of high kinetic energetic photoelectrons. Using the advantage of tuneable X-ray radiation provided by synchrotron sources the photoelectron kinetic energy, i.e. the information depth can be changed and consequently electronic and compositional depth profiles can be obtained. The combination of HAXPES with an atomic structure sensitive technique, as X-ray diffraction, opens a new research field with great potential for many systems in which their electronic properties are intimately linked to their crystallographic structure. At SpLine, the Spanish CRG Beamline at the European Synchrotron Radiation Facility (ESRF) we have developed a novel and exceptional set-up that combine grazing incidence X-ray diffraction (GIXRD) and HAXPES. Both techniques can be operated simultaneously on the same sample and using the same excitation source. The set-up includes a heavy 2S+3D diffractometer and UHV chamber equipped with an electrostatic analyzer. The UHV chamber has also MBE evaporation sources, an ion gun, a LEED optic, a sample heating and cooling

X-ray photoelectron spectroscopy of graphitic carbon nanomaterials doped with heteroatoms

Directory of Open Access Journals (Sweden)

Toma Susi

2015-01-01

Full Text Available X-ray photoelectron spectroscopy (XPS is one of the best tools for studying the chemical modification of surfaces, and in particular the distribution and bonding of heteroatom dopants in carbon nanomaterials such as graphene and carbon nanotubes. Although these materials have superb intrinsic properties, these often need to be modified in a controlled way for specific applications. Towards this aim, the most studied dopants are neighbors to carbon in the periodic table, nitrogen and boron, with phosphorus starting to emerge as an interesting new alternative. Hundreds of studies have used XPS for analyzing the concentration and bonding of dopants in various materials. Although the majority of works has concentrated on nitrogen, important work is still ongoing to identify its precise atomic bonding configurations. In general, care should be taken in the preparation of a suitable sample, consideration of the intrinsic photoemission response of the material in question, and the appropriate spectral analysis. If this is not the case, incorrect conclusions can easily be drawn, especially in the assignment of measured binding energies into specific atomic configurations. Starting from the characteristics of pristine materials, this review provides a practical guide for interpreting X-ray photoelectron spectra of doped graphitic carbon nanomaterials, and a reference for their binding energies that are vital for compositional analysis via XPS.

X-ray-excited Auger and photoelectron spectroscopy

International Nuclear Information System (INIS)

Weightman, P.

1982-01-01

This article reviews developments in the understanding of x-ray-excited Auger and photoelectron spectra in the light of theoretical developments in atomic, molecular and solid-state physics. After reviewing progress in XPS and AES separately emphasis is placed on the inter-relationship between the two fields: Auger rates, for example, are the dominant contribution to core-level XPS linewidths and by combining XPS and AES it is possible to deduce information about Coster-Kronig processes which are difficult to study directly. An account is given of how the combination of measurements of environmentally dependent shifts in XPS and AES energies allows one to isolate initial- and final-state contributions which can then be related to the results of other experimental techniques. There is a brief discussion of many-electron effects and a discussion of how the combination of XPS and AES spectra involving valence levels enables the effects of hole-state localisation to be studied. (author)

X-Ray Photoelectron Spectroscopic Characterization of Iron Oxide Nanoparticles

Energy Technology Data Exchange (ETDEWEB)

Radu, T., E-mail: Teodora.Radu@itim-cj.ro [National Institute for Research and Development of Isotopic and Molecular Technologies, 67-103 Donat Street, 400293, Cluj Napoca (Romania); Iacovita, C. [Department of Pharmaceutical Physics-Biophysics, Faculty of Pharmacy, “Iuliu Hatieganu” University of Medicine and Pharmacy, 400349, Cluj-Napoca (Romania); Benea, D. [Faculty of Physics, Babes Bolyai University, 400271, Cluj-Napoca (Romania); Turcu, R. [National Institute for Research and Development of Isotopic and Molecular Technologies, 67-103 Donat Street, 400293, Cluj Napoca (Romania)

2017-05-31

Highlights: • Characterization of three types of iron oxides magnetic nanoparticles. • A correlation between valence band XPS and the degree of iron oxidation is proposed. • Theoretical contributions of Fe in tetragonal and octahedral environment are shown. - Abstract: We report X-ray photoelectron spectroscopy (XPS) results on iron oxide magnetic nanoparticle (Fe{sub 3}O{sub 4}) synthesized using solvothermal reduction in the presence of polyethylene glycol. The magnetite obtained was employed as precursor for the synthesis of γ-Fe{sub 2}O{sub 3} (by oxygen dissociation) which in turn was transformed into α-Fe{sub 2}O{sub 3}. We confirmed the magnetite, maghemite and hematite structure by Fourier Transformed Spectroscopy (FTIR) and X-ray diffraction (XRD). The analysis of the XPS core level and valence band (VB) photoemission spectra for all investigated samples is discussed in terms of the degree of iron oxidation. This is of fundamental importance to better understand the electronic structure of the obtained iron oxide nanoparticles in order to control and improve their quality for specific biomedical applications. Moreover, theoretical band structure calculations are performed for magnetite and the separate contributions of Fe in tetragonal and octahedral environment are shown.

Development of a portable system of X-ray fluorescence spectrometry

International Nuclear Information System (INIS)

Mantuano, Andrea; Crisostomo, Jose V.V.; Barros, Mariana J.; Oliveira, Luis F.; Barroso, Regina C.

2009-01-01

This paper develops a compact and portable spectrometry system that will be used at the Laboratory of Applied Physics to the Biomedical and Environmental Sciences of the Institute of Physics/UERJ, Rio de Janeiro, Brazil. The laboratory both prepares the samples and develops the X-ray spectrometry techniques. The techniques of X-ray diffraction and fluorescence on various samples (biological, industrial and environmental) are used, attending to pos-graduation and graduation students, with multidisciplinary characteristics. The Mini-X system consists of X-ray mini tube MINI-X from Amptek with tungsten (W) target, and a compact spectrometer X123, also from Amptek that includes a detector, pre-amplifier, digital pulse processor, and multichannel. All the system is controlled by dedicated microprocessor. This work will present both a methodology for alignment and calibration of the system as far the first measurements performed using the X-ray fluorescence technique on standard samples. The multi elementary analysis by X-ray fluorescence (XRF) is based on the measurements of the characteristic X-ray intensity emitted by the chemical elements components of the samples when excited. Therefore, from the development of this compact and versatile system it will be possible to obtain the fluorescent intensities of the analysed samples at the Laboratory, not only at the research area but at the teaching area. Besides, new laboratory practices are being developed for the discipline of medical physics

X-ray spectrometry

International Nuclear Information System (INIS)

Markowicz, A.A.; Van Grieken, R.E.

1986-01-01

In the period under review, i.e, through 1984 and 1985, some 600 articles on XRS (X-ray spectrometry) were published; most of these have been scanned and the most fundamental ones are discussed. All references will refer to English-language articles, unless states otherwise. Also general books have appeared on quantitative EPXMA (electron-probe X-ray microanalysis) and analytical electron microscopy (AEM) as well as an extensive review on the application of XRS to trace analysis of environmental samples. In the period under review no radically new developments have been seen in XRS. However, significant improvements have been made. Gain in intensities has been achieved by more efficient excitation, higher reflectivity of dispersing media, and better geometry. Better understanding of the physical process of photon- and electron-specimen interactions led to complex but more accurate equations for correction of various interelement effects. Extensive use of micro- and minicomputers now enables fully automatic operation, including qualitative analysis. However, sample preparation and presentation still put a limit to further progress. Although some authors find XRS in the phase of stabilization or even stagnation, further gradual developments are expected, particularly toward more dedicated equipment, advanced automation, and image analysis systems. Ways are outlined in which XRS has been improved in the 2 last years by excitation, detection, instrumental, methodological, and theoretical advances. 340 references

X-ray photoelectron spectrometer calibration and thin film investigations on germanium oxides

OpenAIRE

Deegan, Terri

1998-01-01

The first aim of this project was the characterisation of the VG Scientific Clam 100 based, XPS (X-ray Photoelectron Spectroscopy). Spectrometer in the Physics department at Dublin City University Detailed energy scale and intensity scale calibrations were carried out using sputter-cleaned Au (Gold), Ag (Silver), Cu (Copper) and Pd (Palladium) foil samples. Analysis of these calibration spectra against standard reference spectra led to an accurate energy calibration and the production of indi...

Recent progress of soft X-ray photoelectron spectroscopy studies of uranium compounds

Energy Technology Data Exchange (ETDEWEB)

Fujimori, Shin-ichi; Takeda, Yukiharu; Okane, Tetsuo; Saitoh, Yuji [Condensed Matter Science Divisions, Japan Atomic Energy Agency, Sayo, Hyogo (Japan); Fujimori, Atsushi [Condensed Matter Science Divisions, Japan Atomic Energy Agency, Sayo, Hyogo (Japan); Department of Physics, University of Tokyo, Hongo, Tokyo 113-0033 (Japan); Yamagami, Hiroshi [Condensed Matter Science Divisions, Japan Atomic Energy Agency, Sayo, Hyogo (Japan); Department of Physics, Faculty of Science, Kyoto Sangyo University, Kyoto 603-8555 (Japan); Yamamoto, Etsuji; Haga, Yoshinori [Advanced Science Research Center, Japan Atomic Energy Agency, Tokai, Ibaraki 319-1195 (Japan); Ōnuki, Yoshichika [Advanced Science Research Center, Japan Atomic Energy Agency, Tokai, Ibaraki 319-1195 (Japan); Faculty of Science, University of the Ryukyus, Nishihara, Okinawa 903-0213 (Japan)

2016-04-15

Recent progresses in the soft X-ray photoelectron spectroscopy (PES) studies (hν ≳ 100 eV) for uranium compounds are briefly reviewed. The soft X-ray PES has enhanced sensitivities for the bulk U 5f electronic structure, which is essential to understand the unique physical properties of uranium compounds. In particular, the recent remarkable improvement in energy resolutions from an order of 1 eV to 100 meV made it possible to observe fine structures in U 5f density of states. Furthermore, soft X-ray ARPES becomes available due to the increase of photon flux at beamlines in third generation synchrotron radiation facilities.The technique made it possible to observe bulk band structures and Fermi surfaces of uranium compounds and therefore, the results can be directly compared with theoretical models such as band-structure calculations. The core-level spectra of uranium compounds show a systematic behavior depending on their electronic structures, suggesting that they can be utilized to determine basic physical parameters such as the U 5f-ligand hybridizations or Comlomb interaction between U 5f electrons. It is shown that soft X-ray PES provides unique opportunities to understand the electronic structures of uranium compounds.

Determination of rare-earth elements in rocks by isotope-excited X-ray fluorescence spectrometry

DEFF Research Database (Denmark)

Kunzendorf, Helmar; Wollenberg, H.A.

1970-01-01

Isotope-excited X-ray fluorescence spectrometry furnishes a rapid determination of rare-earth elements in unprepared rock samples. The samples are excited by 241Am γ-rays, generating X-ray spectra on a multichannel pulse-height analyser. Gaussian peaks of the Kα and Kβ X-ray energies are treated ......-ray spectrometric scan of a longitudinally sliced drill core showed a close correlation between rare-earth abundances and appropriate minerals.......Isotope-excited X-ray fluorescence spectrometry furnishes a rapid determination of rare-earth elements in unprepared rock samples. The samples are excited by 241Am γ-rays, generating X-ray spectra on a multichannel pulse-height analyser. Gaussian peaks of the Kα and Kβ X-ray energies are treated...

use of x-ray fluorescence spectrometry to determine trace elements ...

African Journals Online (AJOL)

NIJOTECH

Abstract. This paper deals with application of X-ray fluorescence spectrometry for the detection of trace elements in graphic. An X-ray spectrometer was constructed and used to carry out measurements on graphite spheres impregnated with different chemical elements. The intensities of the lines of these trace elements, ...

X-ray fluorescence spectrometry - an introduction course

International Nuclear Information System (INIS)

Salvador, V.L.R.

1989-01-01

The theoretical and experimental principles of the X-ray fluorescence spectrometry, is presented the text is a synthesis of the most important literature in this area. The authors included are: E.P. Bertin, R. Jenkins, J.L. Devries, R. Muller, R. Tertian, F. Claisse e K.L. Willians. (author)

The application of X-ray fluorescence spectrometry to prospecting potential gold deposits

International Nuclear Information System (INIS)

Shang Fengjun; Wang Haixia; Zhou Rongsheng

2001-01-01

The fieldwork high-sensitivity X-ray fluorescence analysis (FXFA) adopting miniaturized X-ray tube, Si-PIN detector with peltier cooler and notebook PC spectrometry is presented. Using this system, the authors carried out a preliminary research of its application to some gold mine in Sichuan. According to the close relationship between the high-grade element arsenic and gold in ore-forming components, X-ray fluorescence spectrometry can be used to reveal the existence of potential gold mineralization in fields rapidly. This is of great significance in guiding the field geological collection

Reduction of Kondo lattice effects in Yb1-xLuxAl3 observed by soft x-ray photoelectron spectroscopy

International Nuclear Information System (INIS)

Yamaguchi, J; Sekiyama, A; Imada, S; Yamasaki, A; Tsunekawa, M; Muro, T; Ebihara, T; Onuki, Y; Suga, S

2007-01-01

We have carried out the bulk-sensitive and high-resolution soft x-ray photoelectron spectroscopy on Lu substituted intermediate-valence compound Yb 1-x Lu x Al 3 (x = 0.4) at temperatures from 200 to 20 K. The temperature dependences of the bulk Yb 4f photoelectron spectra revealed in our preceding works on high purity YbAl 3 have not been observed in this Lu substituted system. The temperature dependences of the bulk Yb 4f peak positions and the Yb valence in this system can be well reproduced by the single impurity Anderson model (SIAM), whereas the spectral behaviors in YbAl 3 were not at all reproduced by the SIAM. These results confirm the importance of the Kondo lattice effects for YbAl 3 , for which the coherent lattice periodicity plays essential roles

X-Ray Photoelectron Spectroscopic Characterization of Chemically Modified Electrodes Used as Chemical Sensors and Biosensors: A Review

Directory of Open Access Journals (Sweden)

Elio Desimoni

2015-04-01

Full Text Available The characterization of chemically modified sensors and biosensors is commonly performed by cyclic voltammetry and electron microscopies, which allow verifying electrode mechanisms and surface morphologies. Among other techniques, X-ray photoelectron spectroscopy (XPS plays a unique role in giving access to qualitative, quantitative/semi-quantitative and speciation information concerning the sensor surface. Nevertheless, XPS remains rather underused in this field. The aim of this paper is to review selected articles which evidence the useful performances of XPS in characterizing the top surface layers of chemically modified sensors and biosensors. A concise introduction to X-ray Photoelectron Spectroscopy gives to the reader the essential background. The application of XPS for characterizing sensors suitable for food and environmental analysis is highlighted.

Assessment of nanocomposite photonic systems with the X-ray photoelectron spectroscopy

Institute of Scientific and Technical Information of China (English)

L. Minati; G. Speranza; M. Anderle; M. Ferrari; A. Chiasera; G. C. Righini

2007-01-01

The chemical compositions of Ag-Er co-doped phosphate and silicate glasses were investigated with X-ray photoelectron spectroscopy with the purpose to identify the chemical state of silver. The analysis of the Ag 3d core lines show the presence of nanometer-sized silver particles in each of the annealed samples, even if these Ag 3d lines appear to be very different from each other. We explain these results as a different interaction of silver with the two glasses matrix, which leads to a different nucleation rate of the Ag clusters.

Practical chemical analysis of Pt and Pd based heterogeneous catalysts with hard X-ray photoelectron spectroscopy

Energy Technology Data Exchange (ETDEWEB)

Yoshikawa, H., E-mail: YOSHIKAWA.Hideki@nims.go.jp [National Institute for Materials Science, 1-2-1 Sengen, Tsukuba, Ibaraki 305-0047 (Japan); Matolínová, I.; Matolín, V. [Charles University in Prague, Faculty of Mathematics and Physics, V Holešovičkách 2, 18000 Prague 8 (Czech Republic)

2013-10-15

Highlights: •Hard X-ray photoelectron spectroscopy (HAXPES) enables interface analysis of catalyst. •HAXPES enables overall analysis of porous film of Pt-doped CeO{sub 2} and related catalyst. •HAXPES enables analysis of trace elements for Pd and Pt{sub 3}Ni nanoparticle catalysts. -- Abstract: Interfacial properties including configuration, porosity, chemical states, and atomic diffusion greatly affect the performance of supported heterogeneous catalysts. Hard X-ray photoelectron spectroscopy (HAXPES) can be used to analyze the interfaces of heterogeneous catalysts because of its large information depth of more than 20 nm. We use HAXPES to examine Pt-doped CeO{sub 2} and related thin film catalysts evaporated on Si, carbon, and carbon nanotube substrates, because Pt-doped CeO{sub 2} has great potential as a noble metal-based heterogeneous catalyst for fuel cells. The HAXPES measurements clarify that the dopant material, substrate material, and surface pretreatment of substrate are important parameters that affect the interfacial properties of Pt-doped CeO{sub 2} and related thin film catalysts. Another advantage of HAXPES measurement of heterogeneous catalysts is that it can be used for chemical analysis of trace elements by detecting photoelectrons from deep core levels, which have large photoionization cross-sections in the hard X-ray region. We use HAXPES for chemical analysis of trace elements in Pd nanoparticle catalysts immobilized on sulfur-terminated substrates and Pt{sub 3}Ni nanoparticle catalysts enveloped by dendrimer molecules.

X-ray Photoelectron Spectroscopy Investigation on Electrochemical Degradation of Proton Exchange Membrane Fuel Cell Electrodes

DEFF Research Database (Denmark)

Andersen, Shuang Ma; Dhiman, Rajnish; Skou, Eivind Morten

2015-01-01

X-ray photoelectron spectroscopy studies were systematically carried out on the electrodes before and after the electrochemical stress tests in an aqueous electrolyte at 20 °C and 70 °C. The electrodes have different ionomer structures (no ionomer, only ionomer, physically mixed ionomer and hot p...

Compilation of monographs on α-, β-, γ- and X-ray spectrometry

International Nuclear Information System (INIS)

Debertin, K.

1977-11-01

The working group 'α-, β-, γ-Ray Spectrometry' of the International Committee for Radionuclide Metrology (ICRM) compiled about 35 monographs on α-, β-, γ- and X-ray spectrometry which were published in the years 1970 to 1976. Support was obtained by the Zentralstelle fuer Atomkernenergie-Dokumentation (ZAED) in Karlsruhe. (orig.) [de

X-ray photoelectron spectroscopy characterization of the ω phase in water quenched Ti-5553 alloy

International Nuclear Information System (INIS)

Qin, Dongyang; Lu, Yafeng; Zhang, Kong; Liu, Qian; Zhou, Lian

2012-01-01

X-ray photoelectron spectroscopy was used to investigate the ω phase in water quenched Ti-5553 alloy with a nominal composition of Ti–5Al–5V–5Mo–3Cr (wt.%), and the ω and the β phase were distinguished by deconvoluting the XPS spectra of Al2p, V2p and Cr2p core level regions. In addition, it is found that the binding energy of core level electron of alloying elements shifts comparing with that of pure metals, and the fact was interpreted by charge redistribution model. X-ray photoelectron spectroscopy technique could be used to characterize the nano-scale ω phase in β alloys. - Highlights: ► We characterize the ω phase in Ti-5553 alloy by XPS. ► Binding energy of Al2p, V2p and Cr2p electron are different in the ω and β phase. ► Structural difference leads to the binding energy gap.

Certification of reference materials by energy-dispersive x-ray fluorescence spectrometry?

DEFF Research Database (Denmark)

Christensen, Leif Højslet; Heydorn, Kaj

1985-01-01

This paper studies the precision and accuracy that can be achieved using energy-dispersive x-ray fluorescence spectrometry for the determination of total sulphur content in BCR 38 Fly Ash issued by the European Community Bureau of Reference.......This paper studies the precision and accuracy that can be achieved using energy-dispersive x-ray fluorescence spectrometry for the determination of total sulphur content in BCR 38 Fly Ash issued by the European Community Bureau of Reference....

An X-ray photoelectron spectroscopic study of the B-N-Ti system

Energy Technology Data Exchange (ETDEWEB)

Seal, S. [Lawrence Berkeley National Lab., CA (United States); Barr, T.L. [Univ. of Wisconsin, Milwaukee, WI (United States); Sobczak, N. [Foundry Research Inst., Cracow (Poland); Benko, E. [Inst. of Metal Cutting, Cracow (Poland); Morgiel, J. [Polish Academy of Sciences, Cracow (Poland). Inst. of Metallurgy and Materials Science

1997-03-01

Composite nitrides (such as BN, TiN) are widely used in various industrial applications because of their extreme wear and corrosion resistance, thermal and electrical properties. In order to obtain composite materials with these optimal properties, it is important to elucidate whether any chemical reactions occur at nitride/metal interfaces, e.g., those involving BN-Ti/TiN. Materials of interest include the deposition by PVD of Ti and TiN on BN substrates. Some of these systems were then subjected to varying degrees of physical and thermal alteration. Detailed X-ray photoelectron spectroscopy (XPS) has therefore been rendered of these interfaces using cross-sectional display and sputter etching. Resulting structural and morphological features have been investigated with transmission electron microscopy (TEM) and X-ray diffraction (XRD). Diffusion of the nitridation, oxynitride formation and interfacial growth are of general interest.

X-ray photoelectron spectroscopy study of pyrolytically coated graphite platforms submitted to simulated electrothermal atomic absorption spectrometry conditions

International Nuclear Information System (INIS)

Ruiz, Frine; Benzo, Zully; Quintal, Manuelita; Garaboto, Angel; Albornoz, Alberto; Brito, Joaquin L.

2006-01-01

The present work is part of an ongoing project aiming to a better understanding of the mechanisms of atomization on graphite furnace platforms used for electrothermal atomic absorption spectrometry (ETAAS). It reports the study of unused pyrolytic graphite coated platforms of commercial origin, as well as platforms thermally or thermo-chemically treated under simulated ETAAS analysis conditions. X-ray photoelectron spectroscopy (XPS) was employed to study the elements present at the surfaces of the platforms. New, unused platforms showed the presence of molybdenum, of unknown origin, in concentrations up to 1 at.%. Species in two different oxidations states (Mo 6+ and Mo 2+ ) were detected by analyzing the Mo 3d spectral region with high resolution XPS. The analysis of the C 1s region demonstrated the presence of several signals, one of these at 283.3 eV related to the presence of Mo carbide. The O 1s region showed also various peaks, including a signal that can be attributed to the presence of MoO 3 . Some carbon and oxygen signals were consistent with the presence of C=O and C-O- (probably C-OH) groups on the platforms surfaces. Upon thermal treatment up to 2900 deg. C, the intensity of the Mo signal decreased, but peaks due to Mo oxides (Mo 6+ and Mo 5+ ) and carbide (Mo 2+ ) were still apparent. Thermo-chemical treatment with 3 vol.% HCl solutions and heating up to 2900 deg. C resulted in further diminution of the Mo signal, with complete disappearance of Mo carbide species. Depth profiling of unused platforms by Ar + ion etching at increasing time periods demonstrated that, upon removal of several layers of carbonaceous material, the Mo signal disappears suggesting that this contamination is present only at the surface of the pyrolytic graphite platform

Introduction to x-ray photoelectron spectroscopy (XPS)

International Nuclear Information System (INIS)

Liesegang, J.; Pigram, P.J.

1999-01-01

Full text: XPS is one of several important surface analytical tools. Developed in Sweden in the 1960s, it was originally named by Kai Siegbahn as Electron Spectroscopy for Chemical Analysis or ESCA; and although it is the best method for non-invasively determining the elemental composition of the first 10 nm of any surface, modern XPS systems are capable of much more than elemental chemical analysis. High resolution photoelectron energy analysis (c. 0.2 eV) now permits easy identification of chemical state as well as concentration; angular variation of detection and depth profiling allow quantitative analysis as a function of depth below a sample surface; energy loss mechanisms may be studied; Auger peaks can be measured in an XPS system; and developments in the area of photoelectron imaging allow high resolution (c. 7 μm) mapping of the distribution of elements and their chemical states to be determined spatially on non-homogeneous surfaces. The workshop sessions will outline the link between the physics and chemistry of surfaces and the process of photoemission. The presentation will illustrate the features and capabilities of a newly acquired Kratos (UK) Axis Ultra XPS and Imaging System recently installed in the Centre for Materials and Surface Science at La Trobe University, and its capabilities regarding the foregoing issues. The first part of the presentation will outline the basics of XPS and the second part will illustrate its usefulness, and in particular, will illustrate the power of the instrumentation through the presentation of several applications of both fundamental and industrial significance. Copyright (1999) Australian X-ray Analytical Association Inc

Surface analysis of Al alloys with X-ray photoelectron and Auger electron spectroscopies

International Nuclear Information System (INIS)

Sakairi, Masatoshi; Suzuki, Keita; Sasaki, Ryo

2015-01-01

In this paper, X-ray photoelectron spectroscopy (XPS) and Auger electron spectroscopy (AES) were applied to investigate passive films formed on aluminum alloy in 0.5 kmol m -3 H 3 BO 3 /0.05 kmol m -3 Na 2 B 4 O 7 with different metal cations. The metal cation is classified by metal cation hardness, X, which are calculated based on the concept of hard and soft acids and bases (HSAB) of the acid and base in Lewis's rule. From XPS analysis, the metal cations with X > 4 were incorporated in passive films. The area-selected surface analysis of AES was also introduced. (author)

X-ray photoelectron spectroscopy study of β-BaB2O4 optical surface

International Nuclear Information System (INIS)

Atuchin, V.V.; Kesler, V.G.; Kokh, A.E.; Pokrovsky, L.D.

2004-01-01

An X-ray photoelectron spectroscopy (XPS) study has been performed for (0 0 1) BaB 2 O 4 . The crystal surface has been polished mechanically and cleaned by chemical etching. In XPS observation, depth profiling has been produced by sputtering with Ar + 3 keV ions. Photoelectron binding energies of original element core levels and valence band have been measured as a function of sputtering time. The persistence of binding energies of barium and boron core levels and valence band structure has been found. For O 1 s core level the formation of new spectral components with lower binding energies has been revealed

Study of non stoichiometric pure and Zr-Doped yttria surfaces by X-Ray photoelectron spectroscopy and scanning electron microscopy

International Nuclear Information System (INIS)

Gautier, M.; Duraud, J.P.; Jollet, F.; Thromat, N.; Maire, P.; Le Gressus, C.

1988-01-01

Surfaces of oxygen-deficient yttrium oxide, pure or Zr-doped, have been studied by means of X-ray photoelectron spectroscopy and scanning electron microscopy. The bulk local geometric structure of these non-stoichiometric compounds was previously determined around the Y atom by an EXAFS (Extended X-ray absorption fine structure) study. The local electronic structure around both Y and O, at the surface, was investigated by X-ray photoelectron spectroscopy. The partial transfer of the electronic distribution between the anion and the cation was probed using the Auger parameter. Coupling of these experiments with microscopic observations show that: - In the pure oxygen-deficient sample, the concentration of oxygen vacancies appears to be increased at the grain boundaries. - The Auger parameter shows upon reduction an evolution of the Y-O bond towards a more covalent one, this evolution being modulated with the presence of Zr0 2

Target characterization by PIXE, alpha spectrometry and X-ray absorption

International Nuclear Information System (INIS)

Kheswa, N.Y.; Papka, P.; Pineda-Vargas, C.A.; Newman, R.T.

2011-01-01

We report on the thickness and homogeneity characterization of thin metallic targets of Zr-96 by means of alpha absorption spectrometry, Particle Induced X-ray Emission (PIXE) and X-ray absorption. The target thicknesses determined by means of the above mentioned methods are critically compared. The thicknesses were determined before and after irradiation with a 70 MeV beam of 14 N ions.

Hard X-ray PhotoElectron Spectroscopy of transition metal oxides: Bulk compounds and device-ready metal-oxide interfaces

International Nuclear Information System (INIS)

Borgatti, F.; Torelli, P.; Panaccione, G.

2016-01-01

Highlights: • Hard X-ray PhotoElectron Spectroscopy (HAXPES) applied to buried interfaces of systems involving Transition Metal Oxides. • Enhanced contribution of the s states at high kinetic energies both for valence and core level spectra. • Sensitivity to chemical changes promoted by electric field across metal-oxide interfaces in resistive switching devices. - Abstract: Photoelectron spectroscopy is one of the most powerful tool to unravel the electronic structure of strongly correlated materials also thanks to the extremely large dynamic range in energy, coupled to high energy resolution that this form of spectroscopy covers. The kinetic energy range typically used for photoelectron experiments corresponds often to a strong surface sensitivity, and this turns out to be a disadvantage for the study of transition metal oxides, systems where structural and electronic reconstruction, different oxidation state, and electronic correlation may significantly vary at the surface. We report here selected Hard X-ray PhotoElectron Spectroscopy (HAXPES) results from transition metal oxides, and from buried interfaces, where we highlight some of the important features that such bulk sensitive technique brings in the analysis of electronic properties of the solids.

Hard X-ray PhotoElectron Spectroscopy of transition metal oxides: Bulk compounds and device-ready metal-oxide interfaces

Energy Technology Data Exchange (ETDEWEB)

Borgatti, F., E-mail: francesco.borgatti@cnr.it [Istituto per lo Studio dei Materiali Nanostrutturati (ISMN), Consiglio Nazionale delle Ricerche (CNR), via P. Gobetti 101, Bologna I-40129 (Italy); Torelli, P.; Panaccione, G. [Istituto Officina dei Materiali (IOM)-CNR, Laboratorio TASC, Area Science Park, Trieste I-34149 (Italy)

2016-04-15

Highlights: • Hard X-ray PhotoElectron Spectroscopy (HAXPES) applied to buried interfaces of systems involving Transition Metal Oxides. • Enhanced contribution of the s states at high kinetic energies both for valence and core level spectra. • Sensitivity to chemical changes promoted by electric field across metal-oxide interfaces in resistive switching devices. - Abstract: Photoelectron spectroscopy is one of the most powerful tool to unravel the electronic structure of strongly correlated materials also thanks to the extremely large dynamic range in energy, coupled to high energy resolution that this form of spectroscopy covers. The kinetic energy range typically used for photoelectron experiments corresponds often to a strong surface sensitivity, and this turns out to be a disadvantage for the study of transition metal oxides, systems where structural and electronic reconstruction, different oxidation state, and electronic correlation may significantly vary at the surface. We report here selected Hard X-ray PhotoElectron Spectroscopy (HAXPES) results from transition metal oxides, and from buried interfaces, where we highlight some of the important features that such bulk sensitive technique brings in the analysis of electronic properties of the solids.

Determination of chlorine in coal by X-ray fluorescence spectrometry method

Energy Technology Data Exchange (ETDEWEB)

Marek, S.; Bojarska, K. [Central Mining Institute, Katowice (Poland). Dept. of Environmental Monitoring

1997-12-31

Determination of chlorine contents in coal is essential for both environmental protection and its technological use. The existing method of chlorine determination in coal are titration methods which have considerable errors particularly in the low concentration range. The elaborated method with the use of X-ray fluorescence spectrometry in a comparison to the other methods is much faster and has better precision and accuracy. The principle of the method lies in the measurement of X-ray fluorescence radiation intensity which is emitted by chlorine in a sample and its comparison with standards. The calibration of the elaborated XRF method is based on natural coals having various concentrations of chlorine within the whole range of its occurrence in Polish coals. Concentrations for the calibration purpose were obtained by the determination of chlorine contents in selected coals by atomic absorption spectrometry method. The procedure of sample preparation for direct X-ray measurements, instrumental measuring conditions and the way of calibration curve preparation are described in the paper. All X-ray measurements were done with a Phillips sequential X-ray fluorescence spectrometer. A double anode Cr-Au X-ray tube with maximum power 3000 MW was used as the excitation source. 5 figs., 4 tabs.

Electrostatic X-ray image recording device with mesh-base photocathode photoelectron discriminator means

International Nuclear Information System (INIS)

1977-01-01

An electrostatic X-ray image recording device having a pair of spaced electrodes with a gas-filled gap therebetween, and including discrimination means, having a conductive mesh supporting a photocathodic material, positioned in the gas-filled gap between a first electrode having a layer of ultraviolet-emitting fluorescent material and a second electrode having a plastic sheet adjacent thereto for receiving photoelectrons emitted by the photocathodic material and accelerated to the second electrode by an applied field. The photoconductor-mesh element discriminates against fast electrons, produced by direct impingement of X-rays upon the photocathode to substantially reduce secondary electron production and amplification, thereby increasing both the signal-to-noise and contrast ratios. The electrostatic image formed on the plastic sheet is developed by zerographic techniques after exposure. (Auth.)

Analysis of eight argonne premium coal samples by X-ray fluorescence spectrometry

Science.gov (United States)

Evans, J.R.; Sellers, G.A.; Johnson, R.G.; Vivit, D.V.; Kent, J.

1990-01-01

X-ray fluorescence spectrometric methods were used in the analysis of eight Argonne Premium Coal Samples. Trace elements (Cr, Ni, Cu, Zn, Rb, Sr, Y, Zr, Nb, Ba, La, and Ce) in coal ash were determined by energy-dispersive X-ray fluorescence spectrometry; major elements (Na, Mg, Al, Si, P, S, K, Ca, Ti, Mn, and Fe) in coal ash and trace elements (Cl and P) in whole coal were determined by wavelength-dispersive X-ray fluorescence spectrometry. The results of this study will be used in a geochemical database compiled for these materials from various analytical techniques. The experimental XRF methods and procedures used to determine these major and trace elements are described.

Method for detecting binding events using micro-X-ray fluorescence spectrometry

Science.gov (United States)

Warner, Benjamin P.; Havrilla, George J.; Mann, Grace

2010-12-28

Method for detecting binding events using micro-X-ray fluorescence spectrometry. Receptors are exposed to at least one potential binder and arrayed on a substrate support. Each member of the array is exposed to X-ray radiation. The magnitude of a detectable X-ray fluorescence signal for at least one element can be used to determine whether a binding event between a binder and a receptor has occurred, and can provide information related to the extent of binding between the binder and receptor.

Installation for β- and X-ray spectrometry

International Nuclear Information System (INIS)

Sokolov, A.D.; Pchelintsev, A.B.; Lupilov, A.V.; Zalinkevich, V.A.; Lapenas, A.

2002-01-01

Paper presents design and parameters of an installation for spectrometry of β- particles and conversion electrons within 15-3000 keV energy range and for X-ray radiation within 2-60 keV range. Si(Li) detector with 500 mm 2 area and 4.5 mm sensitive range thickness is used to record radiation. Energy resolution for 624 keV energy conversion electrons constitutes [ru

X-ray and photoelectron spectroscopy of the structure, reactivity, and electronic structure of semiconductor nanocrystals

Energy Technology Data Exchange (ETDEWEB)

Hamad, Kimberly Sue [Univ. of California, Berkeley, CA (United States)

2000-01-01

Semiconductor nanocrystals are a system which has been the focus of interest due to their size dependent properties and their possible use in technological applications. Many chemical and physical properties vary systematically with the size of the nanocrystal and thus their study enables the investigation of scaling laws. Due to the increasing surface to volume ratio as size is decreased, the surfaces of nanocrystals are expected to have a large influence on their electronic, thermodynamic, and chemical behavior. In spite of their importance, nanocrystal surfaces are still relatively uncharacterized in terms of their structure, electronic properties, bonding, and reactivity. Investigation of nanocrystal surfaces is currently limited by what techniques to use, and which methods are suitable for nanocrystals is still being determined. This work presents experiments using x-ray and electronic spectroscopies to explore the structure, reactivity, and electronic properties of semiconductor (CdSe, InAs) nanocrystals and how they vary with size. Specifically, x-ray absorption near edge spectroscopy (XANES) in conjunction with multiple scattering simulations affords information about the structural disorder present at the surface of the nanocrystal. X-ray photoelectron spectroscopy (XPS) and ultra-violet photoelectron spectroscopy (UPS) probe the electronic structure in terms of hole screening, and also give information about band lineups when the nanocrystal is placed in electric contact with a substrate. XPS of the core levels of the nanocrystal as a function of photo-oxidation time yields kinetic data on the oxidation reaction occurring at the surface of the nanocrystal.

Assembly of positioner of automated two-dimensional scan coupled to X-ray fluorescence spectrometry

International Nuclear Information System (INIS)

Silva, Leonardo Santiago Melgaço

2011-01-01

This work describes the design and assembling of a prototype automated positioner two-dimensional scanning coupled to X-ray fluorescence spectrometry. The work aims to achieve a portable and easy to use, device of broad utility in the analysis of samples by X-ray fluorescence area of expertise and research. The two-dimensional scanning of the positioner is by means of two stepper motors controlled by a microcontroller PIC 16F877A, encoder and optical sensors. The user interacts with the XY table through an interface program for the Windows operating system, which communicates with the microcontroller through the serial port. The system of Fluorescence Spectroscopy incorporated into the positioner consists of a system commercially available system from the company AMPTEK, where the primary source of excitation of the sample was a source of 241 Am of 59.5 KeV emissions. Resolution and accuracy of tests were performed in the XY scanning process and reproducibility of the same kit with the fluorescence spectrometry X-ray. Qualitative tests by X-ray fluorescence spectrometry in samples were performed to demonstrate the applicability and versatility of the project. It follows that the prototype illustrates a possible adequately to portable device for X-ray spectrometry of two-dimensional. (author)

Determination of 239Pu and 240Pu isotope ratio for a nuclear bomb particle using X-ray spectrometry in conjunction with γ-ray spectrometry and non-destructive α-particle spectrometry

International Nuclear Information System (INIS)

Poellaenen, R.; Ruotsalainen, K.; Toivonen, H.

2009-01-01

A nuclear bomb particle from Thule containing Pu and U was analyzed using X-ray spectrometry in combination with γ-ray spectrometry and non-destructive α-spectrometry. The main objective was to investigate the possibility to determine the 239 Pu and 240 Pu isotope ratios. Previously, X-ray spectrometry together with the above-mentioned methods has been successfully applied for radiochemically processed samples, but not for individual particles. In the present paper we demonstrate the power of non-destructive analysis. The 239 Pu/( 239 Pu+ 240 Pu) atom ratio for the Thule particle was determined, using two different approaches, to be 0.93±0.07 and 0.91±0.05. These results are consistent with weapons-grade material and the results obtained by other investigators.

p-Type dopant incorporation and surface charge properties of catalyst-free GaN nanowires revealed by micro-Raman scattering and X-ray photoelectron spectroscopy.

Science.gov (United States)

Wang, Q; Liu, X; Kibria, M G; Zhao, S; Nguyen, H P T; Li, K H; Mi, Z; Gonzalez, T; Andrews, M P

2014-09-07

Micro-Raman scattering and X-ray photoelectron spectroscopy were employed to investigate Mg-doped GaN nanowires. With the increase of Mg doping level, pronounced Mg-induced local vibrational modes were observed. The evolution of longitudinal optical phonon-plasmon coupled mode, together with detailed X-ray photoelectron spectroscopy studies, show that the near-surface region of nanowires can be transformed from weakly n-type to p-type with the increase of Mg doping.

Hybridization and bond-orbital components in site-specific X-ray photoelectron spectra of rutile TiO2

International Nuclear Information System (INIS)

Woicik, J.C.; Nelson, E.J.; Kronik, Leeor; Jain, Manish; Chelikowsky, James R.; Heskett, D.; Berman, L.E.; Herman, G.S.

2002-01-01

We have determined the Ti and O components of the rutile TiO 2 valence band using the method of site-specific x-ray photoelectron spectroscopy. Comparisons with calculations based on pseudopotentials within the local density approximation reveal the hybridization of the Ti 3d, 4s, and 4p states, and the O 2s and 2p states on each site. These chemical effects are observed due to the large differences between the angular-momentum dependent matrix elements of the photoelectron process

Depth-profiling using X-ray photoelectron spectroscopy

International Nuclear Information System (INIS)

Pijolat, M.; Hollinger, G.

1980-12-01

The possibilities of X-ray photoelectron spectroscopy (or ESCA) for depth-profiling into shallow depths (approximately 10-100 A) have been studied. The method of ion-sputtering removal has first been investigated in order to improve its depth-resolution (approximately 50-150 A). A procedure which eliminates the effects due to the resolution function of the instrumental probe (analysed depth approximately 50 A) has been settled; but it is not yet sufficient, and the sputter - broadening due to the ion-induced damages must be taken into account (broadening function approximately 50 A for approximately 150 A removal). Because of serious difficulties in estimating the broadening function an alternative is to develop non destructive methods, so a new method based on the dependence of the analysed depth with the electron emission angle is presented. The extraction of the concentration profile from angular distribution experiments is achieved, in the framework of a flat-layer model, by minimizing the difference between theoretical and experimental relative intensities. The applicability and limitations of the method are discussed on the basis of computer simulation results. The depth probed is of the order of 3 lambda (lambda being the value of the inelastic mean free path, typically 10-20 A) and the depth-resolution is of the order of lambda/3 [fr

X-ray photoelectron spectroscopy of the uranium/oxygen system: Part 13

International Nuclear Information System (INIS)

Allen, G.C.; Stevens, J.C.H.

1987-02-01

The reaction between commercial H 2 and uranium metal leads to the formation of UO 2 due to traces of water vapour or oxygen. When extremely pure H 2 is used uranium hydride may be formed but, even with 99.9999% H 2 , uranium dioxide forms preferentially. The present work identifies the presence of UH 3 in the X-ray photoelectron spectrum of a uranium sample which has been exposed to ∼ 5 mbar H 2 at ∼ 200 0 C for 1 hour. This spectrum indicates that the hydride possesses a high degree of covalency, since the oxidation state of uranium in UH 3 appears to be ∼ 1.4. (U.K.)

Electronic structure simulation of chromium aluminum oxynitride by discrete variational-Xα method and X-ray photoelectron spectroscopy

International Nuclear Information System (INIS)

Choi, Youngmin; Chang, Hyunju; Lee, Jae Do; Kim, Eunah; No, Kwangsoo

2002-01-01

We use a first-principles discrete variational (DV)-Xα method to investigate the electronic structure of chromium aluminum oxynitride. When nitrogen is substituted for oxygen in the Cr-Al-O system, the N2p level appears in the energy range between O2p and Cr3d levels. Consequently, the valence band of chromium aluminum oxynitride becomes broader and the band gap becomes smaller than that of chromium aluminum oxide, which is consistent with the photoelectron spectra for the valence band using X-ray photoelectron spectroscopy (XPS) and ultraviolet photoelectron spectroscopy (UPS). We expect that this valence band structure of chromium aluminum oxynitride will modify the transmittance slope which is a requirement for photomask application. (author)

X-ray fluorescence spectrometry applied to soil analysis

International Nuclear Information System (INIS)

Salvador, Vera Lucia Ribeiro; Sato, Ivone Mulako; Scapin Junior, Wilson Santo; Scapin, Marcos Antonio; Imakima, Kengo

1997-01-01

This paper studies the X-ray fluorescence spectrometry applied to the soil analysis. A comparative study of the WD-XRFS and ED-XRFS techniques was carried out by using the following soil samples: SL-1, SOIL-7 and marine sediment SD-M-2/TM, from IAEA, and clay, JG-1a from Geological Survey of Japan (GSJ)

Characterization of Colloidal Quantum Dot Ligand Exchange by X-ray Photoelectron Spectroscopy

Science.gov (United States)

Atewologun, Ayomide; Ge, Wangyao; Stiff-Roberts, Adrienne D.

2013-05-01

Colloidal quantum dots (CQDs) are chemically synthesized semiconductor nanoparticles with size-dependent wavelength tunability. Chemical synthesis of CQDs involves the attachment of long organic surface ligands to prevent aggregation; however, these ligands also impede charge transport. Therefore, it is beneficial to exchange longer surface ligands for shorter ones for optoelectronic devices. Typical characterization techniques used to analyze surface ligand exchange include Fourier-transform infrared spectroscopy, x-ray diffraction, transmission electron microscopy, and nuclear magnetic resonance spectroscopy, yet these techniques do not provide a simultaneously direct, quantitative, and sensitive method for evaluating surface ligands on CQDs. In contrast, x-ray photoelectron spectroscopy (XPS) can provide nanoscale sensitivity for quantitative analysis of CQD surface ligand exchange. A unique aspect of this work is that a fingerprint is identified for shorter surface ligands by resolving the regional XPS spectrum corresponding to different types of carbon bonds. In addition, a deposition technique known as resonant infrared matrix-assisted pulsed laser evaporation is used to improve the CQD film uniformity such that stronger XPS signals are obtained, enabling more accurate analysis of the ligand exchange process.

X-ray photoelectron spectroscopy study of synchrotron radiation irradiation of a polytetrafluoroethylene surface

CERN Document Server

Haruyama, Y; Matsui, S; Ideta, T; Ishigaki, H

2003-01-01

The effect of synchrotron radiation (SR) irradiation of a polytetrafluoroethylene (PTFE) surface was investigated using X-ray photoelectron spectroscopy (XPS). After the SR irradiation, the relative intensity of the F ls peak to the C ls peak decreased markedly. The chemical composition ratio to the F atoms to C atoms was estimated to be 0.29. From the curve fitting analysis of C ls and F ls XPS spectra, the chemical components and their intensity ratio were determined. The reason for the chemical composition change by the SR irradiation was discussed. (author)

X-ray photoelectron spectroscopy of HUPA organic substances: natural and synthetic humic compounds

International Nuclear Information System (INIS)

Barre, N.; Mercier-Bion, F.; Reiller, P.

2004-01-01

X-ray photoelectron spectroscopy (XPS) results on the characterisation of the HUPA organic materials, i.e. natural humic substances ''GOHY 573'' (fulvic acid FA and humic acid HA) extracted from the Gorleben ground waters, and synthetic humic acids ''M1'' and ''M42'' obtained from a standard melanoidin preparation from FZ Rossendorf, are presented in this paper. XPS investigations were focused on the determination of the chemical environment of the major elements as carbon, nitrogen, oxygen and sulphur, and on the identification of trace metals trapped by these organic compounds. (orig.)

Possible Radiation-Induced Damage to the Molecular Structure of Wooden Artifacts Due to Micro-Computed Tomography, Handheld X-Ray Fluorescence, and X-Ray Photoelectron Spectroscopic Techniques

Directory of Open Access Journals (Sweden)

Madalena Kozachuk

2016-05-01

Full Text Available This study was undertaken to ascertain whether radiation produced by X-ray photoelectron spectroscopy (XPS, micro-computed tomography (μCT and/or portable handheld X-ray fluorescence (XRF equipment might damage wood artifacts during analysis. Changes at the molecular level were monitored by Fourier transform infrared (FTIR analysis. No significant changes in FTIR spectra were observed as a result of μCT or handheld XRF analysis. No substantial changes in the collected FTIR spectra were observed when XPS analytical times on the order of minutes were used. However, XPS analysis collected over tens of hours did produce significant changes in the FTIR spectra.

Effect of oxide charge trapping on x-ray photoelectron spectroscopy of HfO2/SiO2/Si structures

International Nuclear Information System (INIS)

Abe, Yasuhiro; Miyata, Noriyuki; Suzuki, Haruhiko; Kitamura, Koji; Igarashi, Satoru; Nohira, Hiroshi; Ikenaga, Eiji

2009-01-01

We examined the effects of interfacial SiO 2 layers and a surface metal layer on the photoelectron spectra of HfO 2 /SiO 2 /Si structures by hard X-ray photoemission spectroscopy with synchrotron radiation as well as conventional X-ray photoelectron spectroscopy (XPS). The Hf 4f and Hf 3d photoelectron peaks broadened and shifted toward a higher binding energy with increasing thickness of the interfacial SiO 2 layer, even though photoelectrons may have been emitted from the HfO 2 layer with the same chemical composition. Thinning the interfacial Si oxide layer to approximately one monolayer and depositing a metal layer on the HfO 2 surface suppressed these phenomena. The O 1s photoelectron spectra revealed marked differences between the metal- and nonmetal-deposited HfO 2 /SiO 2 /Si structures; HfO 2 and SiO 2 components in the O 1s photoelectron spectra for the metal-deposited structures were observed at reasonably separated binding energies, but those for the nonmetal-deposited structures were not separated clearly. From this behavior concerning the effects of interfacial SiO 2 and surface metal layers, we concluded that the Hf 4f, Hf 3d, and O 1s spectra measured from the HfO 2 /SiO 2 /Si structures did not reflect actual chemical bonding states. We consider that potential variations in the HfO 2 film owing to charge trapping strongly affect the measured photoelectron spectra. On the basis of angle-resolved XPS measurements, we propose that positive charges are trapped at the HfO 2 surface and negative charges are trapped inside the HfO 2 layer. (author)

Soft X ray spectrometry at high count rates

International Nuclear Information System (INIS)

Blanc, P.; Brouquet, P.; Uhre, N.

1978-06-01

Two modifications of the classical method of X-ray spectrometry by a semi-conductor diode permit a count rate of 10 5 c/s with an energy resolution of 350 eV. With a specially constructed pulse height analyzer, this detector can measure four spectra of 5 ms each, in the range of 1-30 keV, during a plasma shot

X-ray photoelectron spectroscopy study of {beta}-BaB{sub 2}O{sub 4} optical surface

Energy Technology Data Exchange (ETDEWEB)

Atuchin, V.V.; Kesler, V.G.; Kokh, A.E.; Pokrovsky, L.D

2004-02-29

An X-ray photoelectron spectroscopy (XPS) study has been performed for (0 0 1) BaB{sub 2}O{sub 4}. The crystal surface has been polished mechanically and cleaned by chemical etching. In XPS observation, depth profiling has been produced by sputtering with Ar{sup +} 3 keV ions. Photoelectron binding energies of original element core levels and valence band have been measured as a function of sputtering time. The persistence of binding energies of barium and boron core levels and valence band structure has been found. For O 1 s core level the formation of new spectral components with lower binding energies has been revealed.

Determination of rare-earth elements in rocks by isotope-excited X-ray fluorescence spectrometry

DEFF Research Database (Denmark)

Kunzendorf, Helmar; Wollenberg, H.A.

1970-01-01

Isotope-excited X-ray fluorescence spectrometry furnishes a rapid determination of rare-earth elements in unprepared rock samples. The samples are excited by 241Am γ-rays, generating X-ray spectra on a multichannel pulse-height analyser. Gaussian peaks of the Kα and Kβ X-ray energies are treated......-ray spectrometric scan of a longitudinally sliced drill core showed a close correlation between rare-earth abundances and appropriate minerals....

X-Ray Fluorescence Spectrometry. II. Determination of Uranium in ores

International Nuclear Information System (INIS)

Bermudez Polonio, J.; Crus Castillo, F. de la; Fernandez Cellini, R.

1961-01-01

A method of analysis of uranium in ores by X-ray spectrometry was developed, using the internal standard technique. Strontium was found to be the most suitable internal standard for general use. A Norelco Philips X-ray fluorescent spectrometer was used in this work, equipped with a lithium fluoride crystal acting as a diffraction grating analyzer. The intensity of the uranium-L α 1 spectral line is calculated and related to corresponding strontium-K α spectral line, both detected with a Scintillation Counter. (Author) 31 refs

Hard-X-ray photoelectron spectroscopy of NaxCoO2.yH2O

International Nuclear Information System (INIS)

Chainani, A.; Yokoya, T.; Takata, Y.; Tamasaku, K.; Taguchi, M.; Shimojima, T.; Kamakura, N.; Horiba, K.; Tsuda, S.; Shin, S.; Miwa, D.; Nishino, Y.; Ishikawa, T.; Yabashi, M.; Kobayashi, K.; Namatame, H.; Taniguchi, M.; Takada, K.; Sasaki, T.; Sakurai, H.; Takayama-Muromachi, E.

2005-01-01

We study the bulk electronic structure of Na x CoO 2 .yH 2 O using Hard X-ray (HX, hν = 5.95KeV) synchrotron photoelectron spectroscopy (PES). The Co 2p core level spectra show well-separated Co 3+ and Co 4+ ions. Cluster calculations suggest low spin Co 3+ and Co 4+ character, and a moderate on-site Coulomb correlation energy U dd ∼3-5.5eV. Photon-dependent valence band PES identifies Co 3d and O 2p derived states, in near agreement with band structure calculations. We discuss the importance of HX-PES for studying correlated transition metal oxides

X rays and condensed matter

International Nuclear Information System (INIS)

Daillant, J.

1997-01-01

After a historical review of the discovery and study of X rays, the various interaction processes between X rays and matter are described: Thomson scattering, Compton scattering, X-photon absorption through photoelectric effect, and magnetic scattering. X ray sources such as the European Synchrotron Radiation Facility (ESRF) are described. The various X-ray applications are presented: imagery such as X tomography, X microscopy, phase contrast; X-ray photoelectron spectroscopy and X-ray absorption spectroscopy; X-ray scattering and diffraction techniques

Application of total reflection X-ray fluorescence spectrometry for ...

Indian Academy of Sciences (India)

Applicability of total reflection X-ray fluorescence (TXRF) spectrometry for trace elemental analysis of rainwater samples was studied. The study was used to develop these samples as rainwater standards by the National University of Singapore (NUS). Our laboratory was one of the participants to use TXRF for this study.

X-ray photoelectron spectroscopy, high-resolution X-ray diffraction ...

Indian Academy of Sciences (India)

the crystalline quality through full-width at half-maximum values. .... angular divergence of ∆α = 12 arc sec. X-rays generated from the monochromator were diffracted from (0 0 6) LiNbO3 atomic planes with the (+, −, −, +, +) geometry. [8].

Automatic sample changer system for a chain of X-Ray Spectrometry

International Nuclear Information System (INIS)

Kall, B.

2004-01-01

Nowadays, the science evolves and the used techniques become more pointed. At the same time, instruments are more powerful. This rule also applies in the domain of the nuclear science. The object of these works goes in this sense and touch the branch of the X-Ray spectrometry and that brings back himself to the conception and the realization of an automatic sample changer system for the chain of X-Ray Spectrometry. Baptized KEN-001 , it is an instrument of sample changer ordered from certain distance. Indeed, the sample carriers are placed of advance in compartments on its tray and by a control, KEN-001 put one by one those reflectors in the carries reflective for analysis. Once the analysis is finished, the system is in charge of taking and replacing the reflector in its compartment of origin. Of this way, one wins in time and therefore in number of analysis to do in an interval of time given. This instrument of precision contributes to the improvement of the analysis and the evolution of the technique of the X-Ray fluorescence [fr

Structural and X-Ray Photoelectron Spectroscopy Study of Al-Doped Zinc-Oxide Thin Films

Directory of Open Access Journals (Sweden)

Bong Ju Lee

2015-01-01

Full Text Available Al-doped zinc-oxide (AZO thin films were prepared by RF magnetron sputtering at different oxygen partial pressures and substrate temperatures. The charge-carrier concentrations in the films decreased from 1.69 × 1021 to 6.16 × 1017 cm−3 with increased gas flow rate from 7 to 21 sccm. The X-ray diffraction (XRD patterns show that the (002/(103 peak-intensity ratio decreased as the gas flow rate increased, which was related to the increase of AZO thin film disorder. X-ray photoelectron spectra (XPS of the O1s were decomposed into metal oxide component (peak A and the adsorbed molecular oxygen on thin films (peak B. The area ratio of XPS peaks (A/B was clearly related to the stoichiometry of AZO films; that is, the higher value of A/B showed the higher stoichiometric properties.

Assigning Oxidation States to Organic Compounds via Predictions from X-ray Photoelectron Spectroscopy: A Discussion of Approaches and Recommended Improvements

Energy Technology Data Exchange (ETDEWEB)

Gupta, Vipul; Ganegoda, Hasitha; Engelhard, Mark H.; Terry, Jeff H.; Linford, Matthew R.

2014-02-11

The traditional assignment of oxidation numbers to organic molecules is problematic. Accordingly, in 1999, Calzaferri proposed a simple and elegant solution that is based on the similar electronegativities of carbon and hydrogen: hydrogen would be assigned an oxidation number of zero when bonded to carbon. Here we show that X-ray photoelectron spectroscopy (XPS), a core electron spectroscopy that is sensitive to oxidation states of elements, confirms his suggestion. In particular, in this work we: (i) list the typical rules for assigning oxidation numbers, (ii) discuss the traditional assignment of oxidation numbers to organic molecules, (iii) review Calzaferri’s solution, (iv) introduce X-ray photoelectron spectroscopy (XPS), (v) show the consistency of Calzaferri’s suggestion with XPS results, (vi) provide supporting examples from the literature, (vii) provide examples from our own research, and (viii) further confirm the Calzaferri suggestion/photoelectron spectroscopy results by discussing two organic well-known reactions. We end by reechoing Calzaferri’s suggestion that the traditional rules for assigning oxidation numbers to organic molecules be modified.

Surface characterization of uranium metal and uranium dioxide using X-ray photoelectron spectroscopy

International Nuclear Information System (INIS)

Allen, G.C.; Trickle, I.R.; Tucker, P.M.

1981-01-01

X-ray photoelectron spectra of pure uranium metal and stoichiometric uranium dioxide have been obtained using an AEI ES300 spectrometer. Binding energy values for core and valence electrons have been determined using an internally calibrated energy scale and monochromatic Al Kα radiation. Satellite peaks observed accompanying certain principal core ionizations are discussed in relation to the mechanisms by which they arise. Confirmation is obtained that for stoichiometric UOsub(2.00) a single shake-up satellite is observed accompanying the U 4fsub(7/2,5/2) principal core lines, separated by 6.8 eV to higher binding energy. (author)

X-Ray Spectrometry for Preventive Conservation Research

International Nuclear Information System (INIS)

Grieken, V. R.

2008-01-01

Preventive conservation studies the influence of environmental conditions on the durability of works of art. X-ray spectrometry (XRS), in its many forms, is one of the main physical analysis techniques used in the context of cultural heritage in view of its non-destructive nature; it is also highly indicated for studying the composition of e.g. harmful atmospheric particles in e.g. museums. A short literature overview will be to illustrate the important role of XRS in conservation. Then some of our own applications of XRS (especially automated electron probe X-ray microanalysis for individual atmospheric particles) will be shown. These include studies in the Wawel Castle in Cracow, Poland (where outdoor soot nanoparticles and deicing salts brought in by visitors were most threatening for the wall tapestry collections) and the Metropolitan Museum in New York, USA (where sodium nitrate particles from the reaction of sea spray with car exhaust gases were predominant in some rooms)

Near edge x-ray spectroscopy theory

International Nuclear Information System (INIS)

1994-01-01

We propose to develop a quantitative theory of x-ray spectroscopies in the near edge region, within about 100 eV of threshold. These spectroscopies include XAFS (X-ray absorption fine structure), photoelectron diffraction (PD), and diffraction anomalous fine structure (DAFS), all of which are important tools for structural studies using synchrotron radiation x-ray sources. Of primary importance in these studies are many-body effects, such as the photoelectron self-energy, and inelastic losses. A better understanding of these quantities is needed to obtain theories without adjustable parameters. We propose both analytical and numerical calculations, the latter based on our x-ray spectroscopy codes FEFF

Summary: Update to ASTM guide E 1523 to charge control and charge referencing techniques in x-ray photoelectron spectroscopy

International Nuclear Information System (INIS)

Baer, D.R.

2005-01-01

An updated version of the American Society for Testing and Materials (ASTM) guide E 1523 to the methods to charge control and charge referencing techniques in x-ray photoelectron spectroscopy has been released by ASTM [Annual Book of ASTM Standards Surface Analysis (American Society for Testing and Materials, West Conshohocken, PA, 2004), Vol. 03.06]. The guide is meant to acquaint x-ray photoelectron spectroscopy (XPS) users with the various charge control and charge referencing techniques that are and have been used in the acquisition and interpretation of XPS data from surfaces of insulating specimens. The current guide has been expanded to include new references as well as recommendations for reporting information on charge control and charge referencing. The previous version of the document had been published in 1997 [D. R. Baer and K. D. Bomben, J. Vac. Sci. Technol. A 16, 754 (1998)

Spectrum unfolding in X-ray spectrometry using the maximum entropy method

International Nuclear Information System (INIS)

Fernandez, Jorge E.; Scot, Viviana; Di Giulio, Eugenio

2014-01-01

The solution of the unfolding problem is an ever-present issue in X-ray spectrometry. The maximum entropy technique solves this problem by taking advantage of some known a priori physical information and by ensuring an outcome with only positive values. This method is implemented in MAXED (MAXimum Entropy Deconvolution), a software code contained in the package UMG (Unfolding with MAXED and GRAVEL) developed at PTB and distributed by NEA Data Bank. This package contains also the code GRAVEL (used to estimate the precision of the solution). This article introduces the new code UMESTRAT (Unfolding Maximum Entropy STRATegy) which applies a semi-automatic strategy to solve the unfolding problem by using a suitable combination of MAXED and GRAVEL for applications in X-ray spectrometry. Some examples of the use of UMESTRAT are shown, demonstrating its capability to remove detector artifacts from the measured spectrum consistently with the model used for the detector response function (DRF). - Highlights: ► A new strategy to solve the unfolding problem in X-ray spectrometry is presented. ► The presented strategy uses a suitable combination of the codes MAXED and GRAVEL. ► The applied strategy provides additional information on the Detector Response Function. ► The code UMESTRAT is developed to apply this new strategy in a semi-automatic mode

Accurate argon cluster-ion sputter yields: Measured yields and effect of the sputter threshold in practical depth-profiling by x-ray photoelectron spectroscopy and secondary ion mass spectrometry

Energy Technology Data Exchange (ETDEWEB)

Cumpson, Peter J.; Portoles, Jose F.; Barlow, Anders J.; Sano, Naoko [National EPSRC XPS User' s Service (NEXUS), School of Mechanical and Systems Engineering, Newcastle University, Newcastle upon Tyne, NE1 7RU (United Kingdom)

2013-09-28

Argon Gas Cluster-Ion Beam sources are likely to become widely used on x-ray photoelectron spectroscopy and secondary ion mass spectrometry instruments in the next few years. At typical energies used for sputter depth profiling the average argon atom in the cluster has a kinetic energy comparable with the sputter threshold, meaning that for the first time in practical surface analysis a quantitative model of sputter yields near threshold is needed. We develop a simple equation based on a very simple model. Though greatly simplified it is likely to have realistic limiting behaviour and can be made useful for estimating sputter yields by fitting its three parameters to experimental data. We measure argon cluster-ion sputter yield using a quartz crystal microbalance close to the sputter threshold, for silicon dioxide, poly(methyl methacrylate), and polystyrene and (along with data for gold from the existing literature) perform least-squares fits of our new sputter yield equation to this data. The equation performs well, with smaller residuals than for earlier empirical models, but more importantly it is very easy to use in the design and quantification of sputter depth-profiling experiments.

Characterization of sintered samples of La/Sr/Cu/O by X-ray diffraction, scanning electron microscopy (SEM) and X-ray photoelectron spectroscopy (XPS)

International Nuclear Information System (INIS)

Gonzalez, C.O. de; Polla, Griselda; Manghi, Estela

1987-01-01

Samples of La/Sr/Cu/O were sinterized by solid state reaction starting from a nominal composition of La 1 .8, Sr 0 .2, CuO 4 . They presented superconductive properties with T c = 40.9 K (onset) and δ T c = 17 K. Two phases were observed by X-ray diffraction and the more abundant was the tetragonal phase. The mean grain size was 1-5 μm. The X-ray photoelectron spectroscopy measurements were carried out using Mg kα (1486.6 eV) as incident radiation. Sample temperature was varied between -180 deg C and 420 deg C, approximately. The temperature variation produces a change in the atomic concentration of the surface components. Deconvolutions of the O 1s peaks show three components with binding energies (B.E.). The decomposition of Cu 2p 3 /2 peaks presents two components corresponding to Cu + and Cu 2+ . (Author) [es

X-ray photoelectron spectroscopy study of excimer laser treated alumina films

Science.gov (United States)

Georgiev, D. G.; Kolev, K.; Laude, L. D.; Mednikarov, B.; Starbov, N.

1998-01-01

Amorphous alumina layers are deposited on a single crystal Si substrate by a e-gun evaporation technique. These films are then thermally annealed in oxygen to be crystallized and, further, irradiated with an excimer laser beam. At each stage of the film preparation, an x-ray photoelectron spectroscopy analysis is performed at the film surface and in depth, upon ion beam grinding. Results give evidence for the formation of an aluminosilicate upon thermal annealing of the film in oxygen. At the surface itself, this compound is observed to decompose upon excimer laser irradiation at energy densities exceeding 1.75 J/cm2, giving rise to free Si atoms and SiO2, however with complete disappearance of Al atoms. Model photochemical reactions are proposed to explain such transformations.

Radiation effects and metalloproteins studied by x-ray photoelectron spectroscopy

International Nuclear Information System (INIS)

Wurzbach, J.A.

1975-07-01

X-ray photoelectron spectroscopy (XPS) is used to study the bonding structure at the iron site of cytochrome c and the bonding of rare earth ions to the phosphate oxygens of ATP. Radiation effects are studied on several amino acid and simple peptide model systems. The emission spectrum of the x-ray source is calculated from literature references. The distributions of photon energy as a function of photon frequency and as a function of take-off angle are obtained. From these distributions, the radiation dose absorbed by an organic sample is found to be 10 6 rads/sec. The C 1s and N 1s spectra of amino acids and peptides are studied to characterize an internal reference standard for protein XPS spectra. Samples of native cytochrome c prepared from solutions of pH 1.5, 3, 7, and 11 are studied. Control samples include porphyrin cytochrome c (PCC), the metal free analogue of the native protein, and microperoxidase (MP), a mixture of heme peptides derived from the peptic digestion of cytochrome c. These samples show two S 2p peaks. The first peak has a binding energy (BE) of 163 eV, which corresponds to the S containing amino acids; the second peak is shifted to 167 eV. This large shift may be the result of Fe-S binding, or oxidation, or both. Low spin ferricytochrome c and ferri-MP were found to have Fe 3p BE's that are unusually low (51 eV) compared to other ferric compounds (54 to 58 eV) and even Fe metal (53 eV). X-ray crystal structures of these compounds show that low spin heme Fe lies in the porphyrin plane; while, high spin heme Fe is displaced above the plane. The N 1s and P 2p spectra of ATP show no change except slight broadening when Nd 3+ is substituted for Na + . Thus, there is no inconsistency with proposals that rare earth ions might be useful as substitutes for alkali metal ions and alkaline earth ions in proteins

X-ray photoelectron spectroscopy study of CO2 reaction with polycrystalline uranium surface

International Nuclear Information System (INIS)

Liu Kezhao; Yu Yong; Zhou Juesheng; Wu Sheng; Wang Xiaolin; Fu Yibei

1999-10-01

The adsorption of CO 2 on 'clean' depleted polycrystalline uranium metal surface has been studied by X-ray photoelectron spectroscopy (XPS) at 300 K. The 'clean' surface were prepared by Ar + ion sputtering under ultra-high vacuum (UHV) condition with a base pressure 6.7 x 10 -8 Pa. The result s shows that adsorption of CO 2 on 'clean' uranium metal took place in total dissociation, and leads to the formation of uranium dioxide, uranium carbides and free carbon. The total dissociation of CO 2 produced carbon, oxygen species, CO 2 2- and CO 3 2- species. The diffusion tendency of carbon was much stronger than that of oxygen, and led to form a carbide in oxide-metal interface while the oxygen remained on their surface as an oxide

Structure of Se-rich As-Se glasses by high-resolution x-ray photoelectron spectroscopy

International Nuclear Information System (INIS)

Golovchak, R.; Kovalskiy, A.; Miller, A. C.; Jain, H.; Shpotyuk, O.

2007-01-01

To establish the validity of various proposed structural models, we have investigated the structure of the binary As x Se 100-x chalcogenide glass family (x≤40) by high-resolution x-ray photoelectron spectroscopy. From the composition dependence of the valence band, the contributions to the density of states from the 4p lone pair electrons of Se and the 4p bonding states and 4s electrons of Se and As are identified in the top part of the band. The analysis of Se 3d and As 3d core-level spectra supports the so-called chain crossing model for the atomic structure of Se-rich As x Se 100-x bulk glasses. The results also indicate small deviations (∼3-8%) from this model, especially for glass compositions with short Se chains (25 40 Se 60 and of Se-Se-Se fragments in a glass with composition x=30 is established

Valence band offset of β-Ga2O3/wurtzite GaN heterostructure measured by X-ray photoelectron spectroscopy.

Science.gov (United States)

Wei, Wei; Qin, Zhixin; Fan, Shunfei; Li, Zhiwei; Shi, Kai; Zhu, Qinsheng; Zhang, Guoyi

2012-10-10

A sample of the β-Ga2O3/wurtzite GaN heterostructure has been grown by dry thermal oxidation of GaN on a sapphire substrate. X-ray diffraction measurements show that the β-Ga2O3 layer was formed epitaxially on GaN. The valence band offset of the β-Ga2O3/wurtzite GaN heterostructure is measured by X-ray photoelectron spectroscopy. It is demonstrated that the valence band of the β-Ga2O3/GaN structure is 1.40 ± 0.08 eV.

Changes in X-ray photoelectron spectra of yttria-tetragonal zirconia polycrystal by ion sputtering

Energy Technology Data Exchange (ETDEWEB)

Watanabe, Eiko; Yoshinari, Masao [Tokyo Dental College, Oral Health Science Center, Tokyo, Chiyoda-ku (Japan)

2016-04-15

This paper reports changes in X-ray photoelectron spectroscopy spectra of yttria-tetragonal zirconia polycrystal (Y-TZP) brought about by Ar ion sputtering. The changes in the core-level spectra of Y-TZP suggest that preferential sputtering of oxygen occurred. A new peak was observed near 0 eV binding energy accompanied with changes in the core-level spectra by the sputtering. After 18 h in a high vacuum following the sputtering, the spectra changed by the sputtering were returned to their original shapes. In contrast, the color of Y-TZP was changed from white to pale brown by X-ray irradiation and was changed from pale brown to dark gray by ion sputtering. However, when the new peak near 0 eV decreased after 18 h, no color change was observed. Therefore, it is thought that the new peak was mainly derived from electrons trapped in various kinds of oxygen vacancies created by the sputtering in other than color centers. (orig.)

Design of a tritium gas cell for beta-ray induced X-ray spectrometry using Monte Carlo simulation

Energy Technology Data Exchange (ETDEWEB)

Hara, Masanori, E-mail: masahara@ctg.u-toyama.ac.jp [Hydrogen Isotope Research Center, Organization for Promotion of Research, University of Toyama, 3190 Gofuku, Toyama City, Toyama 930-8555 (Japan); Abe, Shinsuke; Matsuyama, Masao [Hydrogen Isotope Research Center, Organization for Promotion of Research, University of Toyama, 3190 Gofuku, Toyama City, Toyama 930-8555 (Japan); Aso, Tsukasa [Electronics and Computer Engineering, National Institute of Technology, Toyama College, 1-2 Ebie-neriya, Imizu City, Toyama 933-0293 (Japan); Tatenuma, Katsuyoshi; Kawakami, Tomohiko; Ito, Takeshi [KAKEN Company Limited, 1044 Horimachi, Mito City, Ibaraki 310-0903 (Japan)

2017-06-15

Highlights: • Beta-ray induced X-ray spectrometry (BIXS) is a method for tritium gas analysis. • Gas cell for BIXS was designed by Monte Carlo simulations. • The optimum thickness of the gold layer on a beryllium window was around 150 nm. • This simulation model considered the self-absorption with increasing the cell length. - Abstract: One of the methods used for tritium gas analysis is beta-ray induced X-ray spectrometry (BIXS). Gas cell design is important in this method. The structure of the gas cell for BIXS was optimized by Monte Carlo simulation of beta-ray induced X-ray spectra in various window geometries using the Geant4 tool kit (version 10.01.p02). The simulated spectrum from tritium decay fitted the observed one, and the simulation model was used to obtain the cell parameters for BIXS. The optimum thickness of the gold layer on a beryllium window was around 150 nm. This simulation model also considered the relationship between self-absorption by hydrogen gas and the cell length. Self-absorption increased with increasing cell length and the relationship between the sample pressure and cell length was formulated.

X-ray photoelectron spectrometry

International Nuclear Information System (INIS)

Ebel, M.F.

1986-01-01

The subject is treated under the following headings: historical development, characteristics, qualitative analysis, calibration of the energy scale, unfolding, layer thickness determination, quantitative analysis of non-stoichiometric compounds, and supplementations. 187 references, 29 figures, and 7 tables are given

Analysis of Ti/Mo film by X-ray photoelectron spectroscopy

International Nuclear Information System (INIS)

Mou Fangming; Tu Bing; Yao Bing; Liu Jinhua; Long Xinggui

2002-01-01

Chemical elements and their electronic binding energy on surface of Ti film and bulk are analyzed by X-ray photoelectron spectroscopy (XPS) and Ar + etching. The results show that the surface of specimens is contaminated by carbon and oxygen. Mo on surface of Ti film is from substrate. The XPS spectra of Ti 2p of the etched specimens are fitted on. The results show that Ti chemical states on surface of Ti film are TiO 2 with a content of approaching to 100% and a little Ti. Some TiO 2 will be reduced to low chemical states with the increasing of etching time. The chemical states of Mo on surface of Ti film are MoO 3 and Mo. The content of Mo increases as etching time increasing. Chemical state of carbon on the surface of film is graphite and carbide with binding energy of 288.2-288.9 eV

The Buried Carbon/Solid Electrolyte Interphase in Li-ion Batteries Studied by Hard X-ray Photoelectron Spectroscopy

International Nuclear Information System (INIS)

Ciosek Högström, Katarzyna; Malmgren, Sara; Hahlin, Maria; Gorgoi, Mihaela; Nyholm, Leif; Rensmo, Håkan; Edström, Kristina

2014-01-01

In cycled Li-ion batteries, the carbon negative electrode is buried under a thin passivating layer referred to as the solid electrolyte interphase (SEI). In the present study, the increased depth sensitivity of hard X-ray photoelectron spectroscopy (HAXPES) as compared to conventional X-ray photoelectron spectroscopy (XPS) is used to study electrochemical changes at such a buried carbon/SEI. Samples from graphite/LiFePO 4 cells cycled to specific potentials during the first four charge/discharge cycles were studied. The results show dynamic changes in the SEI during cycling. Reversible, state of charge (SOC) dependent changes in the SEI thickness as well as amounts of lithium oxide, lithium fluoride, lithium and carbon active material were discussed. Moreover, the results indicate lithium enrichment close to the carbon active material surface, which could not be explained by intercalation of lithium into carbon with LiC 6 structure or by SEI formation at the surface. Potential dependent shifts in the binding energy of the carbon active material C1s feature showed the importance of internal energy calibration with an SEI feature rather than carbon active material

X-ray photoelectron spectroscopy investigation of the carburization of 310 stainless steel

International Nuclear Information System (INIS)

Tabet, N.; Allam, I.; Yin, R.C.

2003-01-01

The surface of 310 stainless steel (310SS) samples was investigated by X-ray photoelectron spectroscopy (XPS) after 500 h cyclic exposure to two carburizing atmospheres: CH 4 (2%)-H 2 (98%) at 800 deg. C, and CH 4 (10%)-H 2 (90%) at 1100 deg. C. The depth distribution of various elements in the surface region was obtained by XPS after successive cycles of argon etching. The microstructure of the alloy was observed by scanning electron microscopy (SEM) and the phases formed during the exposure were analyzed by X-ray diffraction (XRD). The results showed that the major phases that were formed within few micrometer depth during exposure at 800 deg. C include both iron and chromium carbides. (Mn, Cr) oxide was also formed as a result of the reaction with the residual oxygen of the atmosphere. A region of few microns width that was relatively depleted of chromium was formed under the surface as a result of the outwards diffusion of chromium. The exposure to the reducing atmosphere at 1100 deg. C led to the formation of various iron and chromium carbides. No oxide was formed during exposure. In all exposed samples, the surface was Cr enriched while nickel remained buried under the surface region that reacted with the atmosphere

Physical methods for studying minerals and solid materials: X-ray, electron and neutron diffraction; scanning and transmission electron microscopy; X-ray, electron and ion spectrometry

International Nuclear Information System (INIS)

Eberhart, J.-P.

1976-01-01

The following topics are discussed: theoretical aspects of radiation-matter interactions; production and measurement of radiations (X rays, electrons, neutrons); applications of radiation interactions to the study of crystalline materials. The following techniques are presented: X-ray and neutron diffraction, electron microscopy, electron diffraction, X-ray fluorescence analysis, electron probe microanalysis, surface analysis by electron emission spectrometry (ESCA and Auger electrons), scanning electron microscopy, secondary ion emission analysis [fr

Combined X-ray CT and mass spectrometry for biomedical imaging applications

Science.gov (United States)

Schioppa, E., Jr.; Ellis, S.; Bruinen, A. L.; Visser, J.; Heeren, R. M. A.; Uher, J.; Koffeman, E.

2014-04-01

Imaging technologies play a key role in many branches of science, especially in biology and medicine. They provide an invaluable insight into both internal structure and processes within a broad range of samples. There are many techniques that allow one to obtain images of an object. Different techniques are based on the analysis of a particular sample property by means of a dedicated imaging system, and as such, each imaging modality provides the researcher with different information. The use of multimodal imaging (imaging with several different techniques) can provide additional and complementary information that is not possible when employing a single imaging technique alone. In this study, we present for the first time a multi-modal imaging technique where X-ray computerized tomography (CT) is combined with mass spectrometry imaging (MSI). While X-ray CT provides 3-dimensional information regarding the internal structure of the sample based on X-ray absorption coefficients, MSI of thin sections acquired from the same sample allows the spatial distribution of many elements/molecules, each distinguished by its unique mass-to-charge ratio (m/z), to be determined within a single measurement and with a spatial resolution as low as 1 μm or even less. The aim of the work is to demonstrate how molecular information from MSI can be spatially correlated with 3D structural information acquired from X-ray CT. In these experiments, frozen samples are imaged in an X-ray CT setup using Medipix based detectors equipped with a CO2 cooled sample holder. Single projections are pre-processed before tomographic reconstruction using a signal-to-thickness calibration. In the second step, the object is sliced into thin sections (circa 20 μm) that are then imaged using both matrix-assisted laser desorption/ionization mass spectrometry (MALDI-MS) and secondary ion (SIMS) mass spectrometry, where the spatial distribution of specific molecules within the sample is determined. The

Fessibility Study on Nitrogen in Explosives using X-ray Photoelectron Spectroscopy: Chemical Fertilizer

International Nuclear Information System (INIS)

Dararutana, P.

2014-01-01

It was known that an explosive is defined as a material which contains a large amount of energy stored in chemical bonds. The energetic stability of gaseous products, and hence, their generation come from the strong bond formation of carbon (mono/di)oxide and (di)nitrogen. Consequently, most commercial explosives are contained -NO 2 , -ONO 2 and/or -NHNO 2 groups which when detonated release gases like the aforementioned ones, e.g., nitroglycerin, TNT, HMX, PETN, nitrocellulose, etc. It was revealed that the elemental compositions, especially N was found in most of the explosive and fertilizer. Chemical fertilizers that used as explosive stimulants were analyzed using X-ray photoelectron spectroscopy (XPS) and scanning electron microscope coupled with energy-dispersive X-ray fluorescence spectroscopy (SEM-EDS). XPS spectra showed relatively high amount of nitrogen (N) in the various samples, especially sample #6 and #7. In addition, the elemental analysis revealed the presence of trace elements. Explosives and fertilizers have differences in specific compositions. It can be concluded that these methods seem to be used as a fingerprint examination to identify various kinds of explosives and fertilizers.

Cu,Cr and As determination in preserved woods (Eucalyptus ssp.) by X-ray fluorescence spectrometries

International Nuclear Information System (INIS)

Pereira Junior, Sergio Matias

2014-01-01

Brazil produces around 2.2 millions of cubic meters of treated wood to meet the annual demand of railway, electric, rural and construction sectors. The most used wood species are eucalyptus (Eucalyptus ssp.) and pine (Pinus ssp.).The treated woods used for poles, sleepers, fence posts and plywoods should be according to Brazilian norms requirements. The most usual wood preservative products used in Brazil are CCA (chromated copper arsenate) and CCB (copper chromium and boron salt). The analytical methods, such as flame atomic absorption spectrometry (FAAS), plasma inductively coupled optical emission spectrometry (ICPOES) and X-ray fluorescence spectrometry (XRFS) have been used for the analytical control of those treatment processes. In this work, the eucalyptus trees (Eucalyptus ssp) samples was obtained from Minas Gerais State, Brazil, cut plantation areas. Under pressure, eucalyptus wood samples were submitted to different concentration of CCA solution reaching 3.9, 6.7, 9.1, 12.4 and 14.0 kg of CCA by m-³ sapwood retentions. Samples in cylinders and sawdust forms were obtained from treated wood samples. Copper, chromium and arsenic determination was performed using the energy dispersive X-ray fluorescence spectrometry (EDXRFS), portable X-ray fluorescence spectrometry (PXRFS), flame atomic absorption spectrometry (FAAS) and instrumental neutron activation analysis. In this work, the method of analysis, sensitivity, precision and accuracy performances of the related techniques were outlined. (author)

X-ray emission spectroscopy. X-ray fluorescence

International Nuclear Information System (INIS)

Despujols, J.

1992-01-01

Principles of X-ray emission spectrometry are first recalled, then wave-length dispersive and energy dispersive X-ray fluorescence spectrometer are described. They are essentially designed for qualitative and quantitative analysis of elements (Z>10). Sample preparation, calibration, corrections, interferences, accuracy are reviewed. Examples of use in different industries are given. (71 refs.)

An X-ray photoelectron spectroscopic study of a nitric acid/argon ion cleaned uranium metal surface at elevated temperature

International Nuclear Information System (INIS)

Paul, A.J.; Sherwood, P.M.A.

1987-01-01

X-ray photoelectron spectroscopy has been used to study the surface of uranium metal cleaned by nitric acid treatment and argon ion etching, followed by heating in a high vacuum. The surface is shown to contain UOsub(2-x) species over the entire temperature range studied. Heating to temperatures in the range 400-600 0 C generates a mixture of this oxide, the metal and a carbide and/or oxycarbide species. (author)

Radiation effects and metalloproteins studied by x-ray photoelectron spectroscopy

Energy Technology Data Exchange (ETDEWEB)

Wurzbach, J.A.

1975-07-01

X-ray photoelectron spectroscopy (XPS) is used to study the bonding structure at the iron site of cytochrome c and the bonding of rare earth ions to the phosphate oxygens of ATP. Radiation effects are studied on several amino acid and simple peptide model systems. The emission spectrum of the x-ray source is calculated from literature references. The distributions of photon energy as a function of photon frequency and as a function of take-off angle are obtained. From these distributions, the radiation dose absorbed by an organic sample is found to be 10/sup 6/ rads/sec. The C 1s and N 1s spectra of amino acids and peptides are studied to characterize an internal reference standard for protein XPS spectra. Samples of native cytochrome c prepared from solutions of pH 1.5, 3, 7, and 11 are studied. Control samples include porphyrin cytochrome c (PCC), the metal free analogue of the native protein, and microperoxidase (MP), a mixture of heme peptides derived from the peptic digestion of cytochrome c. These samples show two S 2p peaks. The first peak has a binding energy (BE) of 163 eV, which corresponds to the S containing amino acids; the second peak is shifted to 167 eV. This large shift may be the result of Fe-S binding, or oxidation, or both. Low spin ferricytochrome c and ferri-MP were found to have Fe 3p BE's that are unusually low (51 eV) compared to other ferric compounds (54 to 58 eV) and even Fe metal (53 eV). X-ray crystal structures of these compounds show that low spin heme Fe lies in the porphyrin plane; while, high spin heme Fe is displaced above the plane. The N 1s and P 2p spectra of ATP show no change except slight broadening when Nd/sup 3 +/ is substituted for Na/sup +/. Thus, there is no inconsistency with proposals that rare earth ions might be useful as substitutes for alkali metal ions and alkaline earth ions in proteins.

Probing hot-electron effects in wide area plasmonic surfaces using X-ray photoelectron spectroscopy

Energy Technology Data Exchange (ETDEWEB)

Ayas, Sencer; Cupallari, Andi; Dana, Aykutlu, E-mail: aykutlu@unam.bilkent.edu.tr [UNAM Institute of Materials Science and Nanotechnology, Bilkent University, 06800 Ankara (Turkey)

2014-12-01

Plasmon enhanced hot carrier formation in metallic nanostructures increasingly attracts attention due to potential applications in photodetection, photocatalysis, and solar energy conversion. Here, hot-electron effects in nanoscale metal-insulator-metal (MIM) structures are investigated using a non-contact X-ray photoelectron spectroscopy based technique using continuous wave X-ray and laser excitations. The effects are observed through shifts of the binding energy of the top metal layer upon excitation with lasers of 445, 532, and 650 nm wavelength. The shifts are polarization dependent for plasmonic MIM grating structures fabricated by electron beam lithography. Wide area plasmonic MIM surfaces fabricated using a lithography free route by the dewetting of evaporated Ag on HfO{sub 2} exhibit polarization independent optical absorption and surface photovoltage. Using a simple model and making several assumptions about the magnitude of the photoemission current, the responsivity and external quantum efficiency of wide area plasmonic MIM surfaces are estimated as 500 nA/W and 11 × 10{sup −6} for 445 nm illumination.

Wavelength Dispersive X-ray Fluorescence Spectrometry for the Analysis of Organic Polymer Film

International Nuclear Information System (INIS)

Choi, Yong Suk; Park, Yong Joon; Kim, Jong Yun

2008-01-01

Recently, many studies have been focused on the thin films because there are numerous industrial processes relevant to thin films such as fuel cells, sensors, lubricants, coatings, and so on. Physical and chemical properties of solid surface have been modified by ultra-thin coatings such as Langmuir-Blodgett (LB) method with a variety of types of organic functional materials for the specific purposes in many applications. In addition, the layer-by-layer technique using polyelectrolyte films are now of interest as biosensors, electrochromic and electroluminescent devices, etc. In general, several methods such as X-ray or neutron reflectivity, and quartz crystal microbalance (QCM) have been utilized for the thin film analysis. These optical techniques can measure the film thicknesses up to hundreds of nanometers while X-ray photoelectron spectroscopy is widely used to study a few nanometers thick films. Other methods such as X-ray Photoelectron spectroscopy (XPS), scanning electron microscopy (SEM), transmission electron microscopy (TEM), and atom force microscopy (AFM) have also been used in the film analysis in spite of some disadvantages for each method. X-ray fluorescence (XRF) has long been used as a rapid and simple analytical tool for the analysis of elemental composition of materials. XRF technique is suitable for on-line or in-line real-time monitoring because it is a non-destructive and rapid analysis with good precision and good accuracy at low cost. The aim of this work is to develop a new analytical technique for the quantitative analysis of polymer film on metal substrate. In the present study, Compton peak profile was investigated under different experimental conditions by using wavelength-dispersive XRF (WD-XRF). Compared to energy-dispersive XRF (ED-XRF), WD-XRF is more adequate in an accurate quantitative analysis of thin organic film

Use of X-ray photoelectron spectroscopy to study radiation and thermal effects in polytetrafluoroethylene

International Nuclear Information System (INIS)

Wheeler, D.R.; Pepper, S.V.

1990-01-01

X-ray photoelectron spectroscopy of the surface and mass spectroscopy of the gas evolved during irradiation and subsequent heating of irradiated polytetrafluoroethylene (PTFE) indicated that the effect of electron irradiation was the same as that of x-irradiation. Saturated fluorocarbon gas was evolved during irradiation and a cross-linked or branched network formed in the surface region. Heating irradiated PTFE to temperatures below 200C resulted in the evolution of additional saturated fluorocarbon gas but no change in the surface. From 200C to 300C, lightly damaged PTFE did not change further, but severely damaged PTFE emitted unsaturated fluorocarbons while the surface underwent apparent partial recovery. These observations demonstrate the thermal instability of the irradiated PTFE surface and allow elaboration of the existing model of radiation damage in PTFE

Valence change detection in memristive oxide based heterostructure cells by hard X-ray photoelectron emission spectroscopy

Science.gov (United States)

Kindsmüller, A.; Schmitz, C.; Wiemann, C.; Skaja, K.; Wouters, D. J.; Waser, R.; Schneider, C. M.; Dittmann, R.

2018-04-01

The switching mechanism of valence change resistive memory devices is widely accepted to be an ionic movement of oxygen vacancies resulting in a valence change of the metal cations. However, direct experimental proofs of valence changes in memristive devices are scarce. In this work, we have employed hard X-ray photoelectron emission microscopy (PEEM) to probe local valence changes in Pt/ZrOx/Ta memristive devices. The use of hard X-ray radiation increases the information depth, thus providing chemical information from buried layers. By extracting X-ray photoelectron spectra from different locations in the PEEM images, we show that zirconia in the active device area is reduced compared to a neighbouring region, confirming the valence change in the ZrOx film during electroforming. Furthermore, we succeeded in measuring the Ta 4f spectrum for two different resistance states on the same device. In both states, as well as outside the device region, the Ta electrode is composed of different suboxides without any metallic contribution, hinting to the formation of TaOx during the deposition of the Ta thin film. We observed a reduction of the Ta oxidation state in the low resistance state with respect to the high resistive state. This observation is contradictory to the established model, as the internal redistribution of oxygen between ZrOx and the Ta electrode during switching would lead to an oxidation of the Ta layer in the low resistance state. Instead, we have to conclude that the Ta electrode takes an active part in the switching process in our devices and that oxygen is released and reincorporated in the ZrOx/TaOx bilayer during switching. This is confirmed by the degradation of the high resistance state during endurance measurements under vacuum.

Low-energy X-ray and gamma spectrometry using silicon photodiodes

International Nuclear Information System (INIS)

Silva, Iran Jose Oliveira da

2000-08-01

The use of semiconductor detectors for radiation detection has increased in recent years due to advantages they present in comparison to other types of detectors. As the working principle of commercially available photodiodes is similar to the semiconductor detector, this study was carried out to evaluate the use of Si photodiodes for low energy x-ray and gamma spectrometry. The photodiodes investigated were SFH-205, SFH-206, BPW-34 and XRA-50 which have the following characteristics: active area of 0,07 cm 2 and 0,25 cm 2 , thickness of the depletion ranging from 100 to 200 μm and junction capacitance of 72 pF. The photodiode was polarized with a reverse bias and connected to a charge sensitive pre-amplifier, followed by a amplifier and multichannel pulse analyzer. Standard radiation source used in this experiment were 241 Am, 109 Cd, 57 Co and 133 Ba. The X-ray fluorescence of lead and silver were also measured through K- and L-lines. All the measurements were made with the photodiodes at room temperature.The results show that the responses of the photodiodes very linear by the x-ray energy and that the energy resolution in FWHM varied between 1.9 keV and 4.4 keV for peaks corresponding to 11.9 keV to 59 keV. The BPW-34 showed the best energy resolution and the lower dark current. The full-energy peak efficiency was also determined and it was observed that the peak efficiency decreases rapidly above 50 keV. The resolution and efficiency are similar to the values obtained with other semiconductor detectors, evidencing that the photodiodes used in that study can be used as a good performance detector for low energy X-ray and gamma spectrometry. (author)

X-ray photoelectron spectrometry and binding energies of Be 1s and O 1s core levels in clinobarylite, BaBe2Si2O7, from Khibiny massif, Kola peninsula

International Nuclear Information System (INIS)

Atuchin, V.V.; Kesler, V.G.; Sapozhnikov, V.K.; Yakovenchuk, V.N.

2008-01-01

The electronic structure of BaBe 2 Si 2 O 7 , clinobarylite, has been investigated by means of X-ray photoelectron spectroscopy (XPS). The valence band of the crystal is mainly formed by Ba 5p, Ba 3s and O 2s states. At higher binding energies the emission lines related to the Si 2p, Be 1s, Si 2s, O 1s and numerous Ba-related states were analyzed in the photoemission spectrum. The Si KLL Auger line has been measured under excitation by the bremsstrahlung X-rays from the Al anode. Chemical bonding effects for Be 1s core level have been considered by comparison with electronic parameters measured for other beryllium containing oxides

X-ray photoelectron spectra structure of actinide compounds stipulated by electrons of the inner valence molecular orbitals (IVMO)

International Nuclear Information System (INIS)

Teterin, Yu. A.; Ivanov, K. E.

1997-01-01

Development of precise X-ray photoelectron spectroscopy using X-ray radiation hν< 1.5 KeV allowed to carry out immediate investigations of fine spectra structure of both weakly bond and deep electrons. Based on the experiments and the obtained results it may be concluded: 1. Under favourable conditions the inner valence molecular orbitals (IVMO) may form in all actinide compounds. 2. The XPS spectra fine structure stipulated by IVMO electrons allows to judge upon the degree of participation of the filled AO electrons in the chemical bond, on the structure o considered atom close environment and the bond lengths in compounds. For amorphous compounds the obtaining of such data based on X-ray structure analysis is restricted. 3. The summary contribution of IVMO electrons to the absolute value of the chemical bonding is comparable with the corresponding value of OMO electrons contribution to the atomic bonding. This fact is very important and new in chemistry. (author)

Structure determination of a multilayer with an island-like overlayer using hard x-ray photoelectron spectroscopy

Energy Technology Data Exchange (ETDEWEB)

Isomura, N., E-mail: isomura@mosk.tytlabs.co.jp; Kataoka, K.; Horibuchi, K.; Dohmae, K.; Kitazumi, K.; Takahashi, N.; Kimoto, Y. [Toyota Central R& D Laboratories, Inc., 41-1 Yokomichi, Nagakute, Aichi 480-1192 (Japan); Oji, H.; Cui, Y.-T.; Son, J.-Y. [Japan Synchrotron Radiation Research Institute (JASRI), 1-1-1 Kouto, Sayo, Hyogo 679-5198 (Japan)

2016-07-27

We use hard X-ray photoelectron spectroscopy (HAXPES) to obtain the surface structure of a multilayer Au/SiO{sub 2}/Si substrate sample with an island-like overlayer. Photoelectron intensities are measured as a function of incident photon energy (PE) and take-off angle (TOA, measured from the sample surface). The Au layer coverage and Au and SiO{sub 2} layer thicknesses are obtained by the PE dependence, and are used for the following TOA analysis. The Au island lateral width in the cross section is obtained by the TOA dependence, including information about surface roughness, in consideration of the island shadowing at small TOAs. In both cases, curve-fitting analysis is conducted. The surface structure, which consists of layer thicknesses, overlayer coverage and island width, is determined nondestructively by a combination of PE and TOA dependent HAXPES measurements.

Silica-supported silicotungstic acid: A study by X-ray photoelectron spectroscopy

Energy Technology Data Exchange (ETDEWEB)

Berry, Frank J.; Derrick, Glyn R. [Department of Chemistry and Analytical Sciences, Robert Hooke Building, Open University, Walton Hall, Milton Keynes, MK7 6AA (United Kingdom); Marco, Jose F. [Instituto de Quimica -Fisica ' Rocasolano' , Consejo Superior de Investigaciones Cientificas, Serrano 119, 28006 Madrid (Spain); Mortimer, Michael [Department of Chemistry and Analytical Sciences, Robert Hooke Building, Open University, Walton Hall, Milton Keynes, MK7 6AA (United Kingdom)], E-mail: m.mortimer@open.ac.uk

2009-04-15

W 4f and O 1s X-ray photoelectron spectra for silicotungstic acid, H{sub 4}SiW{sub 12}O{sub 40}, in pure and silica-supported form are reported. W 4f XP spectra for the supported acid are analysed in terms of contributions from two W(VI) spin-orbit doublets arising from tungsten atoms in terminal W=O bonds some of which directly interact with the silica surface. At low loading (3.2 wt.%) significant changes in the relative contributions and binding energies of the two spin-orbit doublets are taken as evidence of a strong interaction of individual [SiW{sub 12}O{sub 40}]{sup 4-} anions with highly active sites on the silica surface. It is suggested that selective ordering of silanol groups can occur on the silica surface in order to accommodate the adsorption of individual [SiW{sub 12}O{sub 40}]{sup 4-} anions.

Photoelectron spectroscopy

International Nuclear Information System (INIS)

Shirley, D.A.

1976-01-01

Research activities in photoelectron spectroscopy at Lawrence Radiation Laboratory during 1976 are described. Topics covered include: the orientation of CO on Pt(III) and Ni(III) surfaces from angle-resolved photoemission; photoemission from CO on Pt(III) in the range 40 eV less than or equal to dirac constant ω less than or equal to 150 eV; photoemission studies of electron states at clean surfaces using synchrotron radiation; angle and energy dependent photoemission studies of plasmon loss structure in Al and In; d-orbital directed photoemission from copper; interpretation of angle-resolved x-ray photoemission from valence bands; atomic cross-section effects in soft x-ray photoemission from Ag, Au, and Pt valence bands; x-ray photoelectron spectroscopic studies of the electronic structure of transition metal difluorides; x-ray photoemission investigation of the density of states of B'-NiAl; the electronic structure of SrTiO 3 and some simple related oxides; fluorescence lifetime measurements of np 5 (n+1)S' states in krypton and xenon; Zeeman beats in the resonance fluorescence of the 3P 1 , states in krypton and xenon; lifetime measurements of rare-gas dimers; configuration interaction effects in the atomic photoelectron spectra of Ba, Sm, Eu, and Yb; glow discharge lamps as electron sources for electron impact excitation; electron impact excitation of electron correlation states in Ca, Sr, and Ba; photoelectron spectroscopy of atomic and molecular bismuth; relativistic effects in the uv photoelectron spectra of group VI diatomic molecules; and relative gas-phase acidities and basicities from a proton potential model

Lyophilized histidine investigated using X-ray photoelectron spectroscopy and cryogenics: Deprotonation in vacuum

Energy Technology Data Exchange (ETDEWEB)

Cardenas, Juan F. [Inorganic Chemistry, Umeaa University, 90187 Umeaa (Sweden)]. E-mail: juan.cardenas@chem.umu.se; Groebner, Gerhard [Biophysical Chemistry, Umeaa University, 90187 Umeaa (Sweden)

2005-08-15

Lyophilized histidine samples were investigated using X-ray photoelectron spectroscopy (XPS). Lyophilized samples were prepared from aqueous solutions at a pH in the range between {approx}1.5 and {approx}10, and with no further addition of electrolyte. The use of cryogenics allowed the determination of protonated to unprotonated molar ratios of sites in L-histidine, which correlates well with the dissociation constants of the residual amino acid sites. When cryogenics was not used deprotonation of the lyophilized samples occurred, where the degree and the total concentration of deprotonated sites correlates well with the formation constants and the decrease in Cl concentration, respectively. This later relation clearly indicates a correlation between deprotonation and the desorption of HCl from lyophilized samples.

Lyophilized histidine investigated using X-ray photoelectron spectroscopy and cryogenics: Deprotonation in vacuum

International Nuclear Information System (INIS)

Cardenas, Juan F.; Groebner, Gerhard

2005-01-01

Lyophilized histidine samples were investigated using X-ray photoelectron spectroscopy (XPS). Lyophilized samples were prepared from aqueous solutions at a pH in the range between ∼1.5 and ∼10, and with no further addition of electrolyte. The use of cryogenics allowed the determination of protonated to unprotonated molar ratios of sites in L-histidine, which correlates well with the dissociation constants of the residual amino acid sites. When cryogenics was not used deprotonation of the lyophilized samples occurred, where the degree and the total concentration of deprotonated sites correlates well with the formation constants and the decrease in Cl concentration, respectively. This later relation clearly indicates a correlation between deprotonation and the desorption of HCl from lyophilized samples

Analysis of electron-irradiated poly-ether ether ketone by X-ray photoelectron spectroscopy

International Nuclear Information System (INIS)

Oyabu, Matashige; Kobayashi, Yoshinori; Seguchi, Tadao; Sasuga, Tsuneo; Kudoh, Hisaaki.

1995-01-01

Organic polymers used in atomic power plants or space are damaged by ionizing irradiation. Radicals produced by irradiation cause oxidation, chain scission and crosslinking, all of which lead to degradation of the material. In this paper, the surface of electron-irradiated poly-ether ether ketone (PEEK) was studied by X-ray photoelectron spectroscopy (XPS). The irradiation in air was found to oxidize the PEEK surface producing carboxyl groups, the content of which dependant on the dose. Carboxyl groups were not produced in helium gas. Quantitative spectral analysis indicated that the aromatic structure might be decomposed. Some comparison was made between the semicrystalline and amorphous samples. The oxygen content resulting from irradiation, of semicrystalline PEEK increased more than that of amorphous PEEK. (author)

Study of strontium- and magnesium-doped lanthanum gallate solid electrolyte surface by X-ray photoelectron spectroscopy

International Nuclear Information System (INIS)

Datta, Pradyot; Majewski, Peter; Aldinger, Fritz

2008-01-01

The chemical states of the surface of the oxygen ion conducting solid electrolyte La 0.9 Sr 0.1 Ga 0.85 Mg 0.15 O 3-δ (LSGM 1015) as prepared by solid-state synthesis was analyzed by X-ray photoelectron spectroscopy. It was found that adventitious carbon did not interact with any of the constituent elements of LSGM 1015. Ga and La were found to exist in trivalent states. But, due to ionic bombardment presence of Mg could not be detected in the electrolyte surface

UHV photoelectron x-ray beam position monitor

International Nuclear Information System (INIS)

Johnson, E.D.; Oversluizen, T.

1989-01-01

As part of our research program to develop viable beam position monitors for both the X-ray and VUV beamlines at the NSLS, we have constructed vertical photon beam position monitors which are presently mounted in two front-ends in the X-ray ring. These area-type detectors are located before the safety shutters and are, therefore, able to monitor the beam position even during injection. The features of this type of monitor which contribute to its long-term stability, position sensitivity, and immunity to horizontal beam motion have been examined and will be discussed. 6 refs., 4 figs

X-ray sky

International Nuclear Information System (INIS)

Gruen, M.; Koubsky, P.

1977-01-01

The history is described of the discoveries of X-ray sources in the sky. The individual X-ray detectors are described in more detail, i.e., gas counters, scintillation detectors, semiconductor detectors, and the principles of X-ray spectrometry and of radiation collimation aimed at increased resolution are discussed. Currently, over 200 celestial X-ray sources are known. Some were identified as nebulae, in some pulsations were found or the source was identified as a binary star. X-ray bursts of novae were also observed. The X-ray radiation is briefly mentioned of spherical star clusters and of extragalactic X-ray sources. (Oy)

Magnetic x-ray dichroism in ultrathin epitaxial films

Energy Technology Data Exchange (ETDEWEB)

Tobin, J.G.; Goodman, K.W. [Lawrence Berkeley National Lab., CA (United States); Cummins, T.R. [Univ. of Missouri, Rolla, MO (United States)] [and others

1997-04-01

The authors have used Magnetic X-ray Linear Dichroism (MXLD) and Magnetic X-ray Circular Dichroism (MXCD) to study the magnetic properties of epitaxial overlayers in an elementally specific fashion. Both MXLD and MXCD Photoelectron Spectroscopy were performed in a high resolution mode at the Spectromicroscopy Facility of the ALS. Circular Polarization was obtained via the utilization of a novel phase retarder (soft x-ray quarter wave plate) based upon transmission through a multilayer film. The samples were low temperature Fe overlayers, magnetic alloy films of NiFe and CoNi, and Gd grown on Y. The authors results include a direct comparison of high resolution angle resolved Photoelectron Spectroscopy performed in MXLD and MXCD modes as well as structural studies with photoelectron diffraction.

Magnetic x-ray dichroism in ultrathin epitaxial films

International Nuclear Information System (INIS)

Tobin, J.G.; Goodman, K.W.; Cummins, T.R.

1997-01-01

The authors have used Magnetic X-ray Linear Dichroism (MXLD) and Magnetic X-ray Circular Dichroism (MXCD) to study the magnetic properties of epitaxial overlayers in an elementally specific fashion. Both MXLD and MXCD Photoelectron Spectroscopy were performed in a high resolution mode at the Spectromicroscopy Facility of the ALS. Circular Polarization was obtained via the utilization of a novel phase retarder (soft x-ray quarter wave plate) based upon transmission through a multilayer film. The samples were low temperature Fe overlayers, magnetic alloy films of NiFe and CoNi, and Gd grown on Y. The authors results include a direct comparison of high resolution angle resolved Photoelectron Spectroscopy performed in MXLD and MXCD modes as well as structural studies with photoelectron diffraction

Standard test methods for chemical analysis of ceramic whiteware materials using wavelength dispersive X-Ray fluorescence spectrometry

CERN Document Server

American Society for Testing and Materials. Philadelphia

2004-01-01

1.1 These test methods cover the determination of ten major elements (SiO2, Al2O3, Fe2O3, MgO, CaO, Na2O, K2O, TiO2, P2O5, MnO, and LOI in ceramic whitewares clays and minerals using wavelength dispersive X-ray fluorescence spectrometry (WDXRF). The sample is first ignited, then fused with lithium tetraborate and the resultant glass disc is introduced into a wavelength dispersive X-ray spectrometer. The disc is irradiated with X-rays from an X-ray tube. X-ray photons emitted by the elements in the samples are counted and concentrations determined using previously prepared calibration standards. (1) In addition to 10 major elements, the method provides a gravimetric loss-on-ignition. Note 1—Much of the text of this test method is derived directly from Major element analysis by wavelength dispersive X-ray fluorescence spectrometry, included in Ref (1). 1.2 Interferences, with analysis by WDXRF, may result from mineralogical or other structural effects, line overlaps, and matrix effects. The structure of the...

Dynamic secondary ion mass spectrometry and X-ray photoelectron spectroscopy on artistic bronze and copper artificial patinas

International Nuclear Information System (INIS)

Balta, I.Z.; Pederzoli, S.; Iacob, E.; Bersani, M.

2009-01-01

To prevent the natural processes of decay and to develop and improve the treatments of conservation and restoration of artistic bronzes meaning statues and sculptures, it is important understanding the patination processes and the knowledge of artificially corroded surfaces. Chemical and physical characterization of artificial patinas obtained on artistic bronzes and coppers by using the 19th century Western traditional patination techniques and recipes by means of SEM-EDS, light microscopy and ATR/FT-IR has been done in previous studies [I.Z. Balta, L. Robbiola, Characterization of artificial black patinas on artistic cast bronze and pure copper by using SEM-EDS and light microscopy, in: Proceedings of the 13th European Microscopy Congress, 22-27 August 2004, Antwerp, Belgium, EMC 2004 CD-Rom Conference Preprints; I.Z. Balta, L. Robbiola, Traditional artificial artistic bronze and copper patinas-an investigation by SEM-EDS and ATR/FT-IR, in: Proceedings of the 8th International Conference on Non Destructive Investigations and Microanalysis for the Diagnostics and Conservation of the Cultural and Environmental Heritage, 15-19 May 2005, Lecce, Italy, ART'05 CD-Rom Conference Preprints]. Differences in morphology (structure, thickness, porosity, adherence, compactity, uniformity, homogeneity) and also in composition, on both artistic cast bronze and pure copper patinas, were clearly evidenced. Further in-depth investigation is required to be carried out in order to better understand the patinas mechanisms of formation and the layers kinetics of growth. The elemental and chemical analysis, either on a surface monolayer or in a depth profile, by using the Secondary Ion Mass Spectrometry (SIMS) and X-ray Photoelectron Spectroscopy (XPS) techniques, can provide this kind of information, unique at trace-level sensitivity. SIMS has proved to be a suitable analytical technique for analyzing small amounts of material with high atomic sensitivity (ppm or even ppb) and high

Dynamic secondary ion mass spectrometry and X-ray photoelectron spectroscopy on artistic bronze and copper artificial patinas

Energy Technology Data Exchange (ETDEWEB)

Balta, I.Z., E-mail: balta_z_i@yahoo.com [National Research Institute for Conservation and Restoration, Calea Victoriei 12, Sector 3, 030026 Bucharest (Romania); Pederzoli, S.; Iacob, E.; Bersani, M. [Fondazione Bruno Kessler - IRST, Centro per la Ricerca Scientifica e Tecnologica, Trento (Italy)

2009-04-01

To prevent the natural processes of decay and to develop and improve the treatments of conservation and restoration of artistic bronzes meaning statues and sculptures, it is important understanding the patination processes and the knowledge of artificially corroded surfaces. Chemical and physical characterization of artificial patinas obtained on artistic bronzes and coppers by using the 19th century Western traditional patination techniques and recipes by means of SEM-EDS, light microscopy and ATR/FT-IR has been done in previous studies [I.Z. Balta, L. Robbiola, Characterization of artificial black patinas on artistic cast bronze and pure copper by using SEM-EDS and light microscopy, in: Proceedings of the 13th European Microscopy Congress, 22-27 August 2004, Antwerp, Belgium, EMC 2004 CD-Rom Conference Preprints; I.Z. Balta, L. Robbiola, Traditional artificial artistic bronze and copper patinas-an investigation by SEM-EDS and ATR/FT-IR, in: Proceedings of the 8th International Conference on Non Destructive Investigations and Microanalysis for the Diagnostics and Conservation of the Cultural and Environmental Heritage, 15-19 May 2005, Lecce, Italy, ART'05 CD-Rom Conference Preprints]. Differences in morphology (structure, thickness, porosity, adherence, compactity, uniformity, homogeneity) and also in composition, on both artistic cast bronze and pure copper patinas, were clearly evidenced. Further in-depth investigation is required to be carried out in order to better understand the patinas mechanisms of formation and the layers kinetics of growth. The elemental and chemical analysis, either on a surface monolayer or in a depth profile, by using the Secondary Ion Mass Spectrometry (SIMS) and X-ray Photoelectron Spectroscopy (XPS) techniques, can provide this kind of information, unique at trace-level sensitivity. SIMS has proved to be a suitable analytical technique for analyzing small amounts of material with high atomic sensitivity (ppm or even ppb) and

A high pressure x-ray photoelectron spectroscopy experimental method for characterization of solid-liquid interfaces demonstrated with a Li-ion battery system

Energy Technology Data Exchange (ETDEWEB)

Maibach, Julia; Xu, Chao; Gustafsson, Torbjörn; Edström, Kristina [Department of Chemistry–Ångström Laboratory, Uppsala University, Box 538, SE-751 21 Uppsala (Sweden); Eriksson, Susanna K. [Department of Chemistry–Ångström Laboratory, Uppsala University, Box 523, SE-751 20 Uppsala (Sweden); Åhlund, John [VG Scienta AB, Box 15120, SE-750 15 Uppsala (Sweden); Siegbahn, Hans; Rensmo, Håkan; Hahlin, Maria, E-mail: maria.hahlin@physics.uu.se [Department of Physics and Astronomy, Uppsala University, Box 516, SE-751 20 Uppsala (Sweden)

2015-04-15

We report a methodology for a direct investigation of the solid/liquid interface using high pressure x-ray photoelectron spectroscopy (HPXPS). The technique was demonstrated with an electrochemical system represented by a Li-ion battery using a silicon electrode and a liquid electrolyte of LiClO{sub 4} in propylene carbonate (PC) cycled versus metallic lithium. For the first time the presence of a liquid electrolyte was realized using a transfer procedure where the sample was introduced into a 2 mbar N{sub 2} environment in the analysis chamber without an intermediate ultrahigh vacuum (UHV) step in the load lock. The procedure was characterized in detail concerning lateral drop gradients as well as stability of measurement conditions over time. The X-ray photoelectron spectroscopy (XPS) measurements demonstrate that the solid substrate and the liquid electrolyte can be observed simultaneously. The results show that the solid electrolyte interphase (SEI) composition for the wet electrode is stable within the probing time and generally agrees well with traditional UHV studies. Since the methodology can easily be adjusted to various high pressure photoelectron spectroscopy systems, extending the approach towards operando solid/liquid interface studies using liquid electrolytes seems now feasible.

X-ray photoelectron spectroscopic evidence for bacteria-enhanced dissolution of hornblende

Science.gov (United States)

Kalinowski, B. E.; Liermann, L. J.; Brantley, S. L.; Barnes, A.; Pantano, C. G.

2000-04-01

An Arthrobacter species capable of extracting Fe from hornblende was isolated from a soil from the Adirondacks, NY (USA). This bacteria isolate, used in batch experiments with hornblende, accelerated the release of Fe from hornblende without measurably affecting Al release. The isolate produces both low molecular weight organic acids (LMWOA) and a catecholate siderophore. Polished hornblende (glass and crystal) discs were analyzed with X-ray photoelectron spectroscopy (XPS) before and after incubation with growing Arthrobacter sp. to investigate whether the bacteria caused a distinguishable chemical signature on the upper 100 Å of mineral surface. After removal of the arthrobacter grown on hornblende crystal or glass substrates using lysozyme, XPS revealed surface depletion of Fe for samples grown for several days in buffered (crystal) and unbuffered (crystal and glass) media. Fe/Si ratios of hornblende surfaces dissolved under biotic conditions are significantly lower than Fe/Si ratios on surfaces dissolved under abiotic conditions for similar amounts of time. Enhanced Fe release and the formation of Fe-depleted surfaces is inferred to be caused by catechol complexation at the mineral surface. Because natural siderophore was not isolated in sufficient quantities to run bacteria-free leaching experiments, parallel investigations were run with a commercially available siderophore (desferrioxamine B). Desferrioxamine B was observed to enhance release of Fe, Si, and Al from hornblende both with and without added bacteria. Formation of desferrioxamine-Fe surface complexes were probed by studying the multiple splitting and shift in intensities of the N 1s line analyzed by XPS on siderophore ± Fe on gold surfaces and siderophore + hornblende crystal surfaces. Based upon the observed formation of an hydroxamate (desferrioxamine) surface complex on hornblende, we infer that catecholate siderophores, such as those produced by the arthrobacter, also complex on the

Influence of polymolybdate adsorbates on electrooxidation of ethanol at PtRu nanoparticles: Combined electrochemical, mass spectrometric and X-ray photoelectron spectroscopic studies

Science.gov (United States)

Gralec, Barbara; Lewera, Adam; Kulesza, Pawel J.

2016-05-01

The role Keggin-type phosphomolybdate (PMo12O403-) ions (adsorbed on carbon-supported PtRu, PtRu/C) on electrooxidation of ethanol is addressed here. The combined results obtained using Differential Electrochemical Mass Spectrometry, X-ray Photoelectron Spectroscopy and Cyclic Voltammetry are consistent with the view that presence of the Keggin-type polyoxometallate, phosphomolybdate, ions (adsorbates) leads to enlargement of the current densities associated with electrooxidation of ethanol at potentials greater than 700 mV vs. RHE. This increase of the anodic currents is correlated with the higher acetaldehyde yield which is likely to reflect changes in the reaction kinetics (e.g. more dynamic dehydrogenation of ethanol leading to acetaldehyde) or in the reaction mechanism defined by the preferential surface modification resulting not only in faster kinetics but also in higher selectivity with respect to acetaldehyde production. It is apparent from the spectroscopic data that modification of PtRu/C nanoparticles with phosphomolybdate ions leads to suppression of the formation of Ru surface oxides.

Chemical analysis of zinc electroplating solutions by x-ray fluorescence spectrometry

International Nuclear Information System (INIS)

Jung, Sung-Mo; Cho, Young-Mo; Na, Han-Gil

2007-01-01

A quantitative analysis method used to analyze chlorine, iron and zinc in electroplating solutions, using X-ray spectrometry in atmospheric He mode, is proposed. The present research concerns the replacement of the conventional analyses of electroplating solutions with rapid and reproducible quantification using X-ray fluorescence spectrometer. An in-depth investigation conducted in the present study identifies the species present in the real electroplating solutions. XRD patterns and semi-quantitative results for the electroplating solutions show synthetic standards based on the compositional range of solutions by analyzing the electroplating solutions obtained in real processes. 28 calibration standard solutions are prepared by diluting liquid standard solutions certified by titration and ICP-OES analyses used to construct the XRF calibration curves for Cl, Fe and Zn. The suggested method showed satisfactory precision and accuracy in the analysis of electroplating solutions. The present study provides evidences that the proposed XRF spectrometry could be an alternative analytical method to replace the conventional techniques by comparing the uncertainties estimated for each method. (author)

Non-destructive assessment of the polarity of GaN nanowire ensembles using low-energy electron diffraction and x-ray photoelectron diffraction

Czech Academy of Sciences Publication Activity Database

Romanyuk, Olexandr; Fernández-Garrido, S.; Jiříček, Petr; Bartoš, Igor; Geelhaar, L.; Brandt, O.; Paskova, T.

2015-01-01

Roč. 106, č. 2 (2015), "021602-1"-"021602-4" ISSN 0003-6951 Grant - others:AVČR(CZ) M100101201 Institutional support: RVO:68378271 Keywords : GaN nanowires * X-ray photoelectron diffraction * LEED I-V * GaN polarity Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 3.142, year: 2015

Is scanning electron microscopy/energy dispersive X-ray spectrometry (SEM/EDS) quantitative?

Science.gov (United States)

Newbury, Dale E; Ritchie, Nicholas W M

2013-01-01

Scanning electron microscopy/energy dispersive X-ray spectrometry (SEM/EDS) is a widely applied elemental microanalysis method capable of identifying and quantifying all elements in the periodic table except H, He, and Li. By following the "k-ratio" (unknown/standard) measurement protocol development for electron-excited wavelength dispersive spectrometry (WDS), SEM/EDS can achieve accuracy and precision equivalent to WDS and at substantially lower electron dose, even when severe X-ray peak overlaps occur, provided sufficient counts are recorded. Achieving this level of performance is now much more practical with the advent of the high-throughput silicon drift detector energy dispersive X-ray spectrometer (SDD-EDS). However, three measurement issues continue to diminish the impact of SEM/EDS: (1) In the qualitative analysis (i.e., element identification) that must precede quantitative analysis, at least some current and many legacy software systems are vulnerable to occasional misidentification of major constituent peaks, with the frequency of misidentifications rising significantly for minor and trace constituents. (2) The use of standardless analysis, which is subject to much broader systematic errors, leads to quantitative results that, while useful, do not have sufficient accuracy to solve critical problems, e.g. determining the formula of a compound. (3) EDS spectrometers have such a large volume of acceptance that apparently credible spectra can be obtained from specimens with complex topography that introduce uncontrolled geometric factors that modify X-ray generation and propagation, resulting in very large systematic errors, often a factor of ten or more. © Wiley Periodicals, Inc.

Energy dispersive x-ray spectrometry by microcalorimetry for the SEM

CERN Document Server

Newbury, D; Sae Woo Nam; Hilton, G; Irwin, K; Small, J; Martinis, J

2002-01-01

Analytical x-ray spectrometry for electron beam instruments has advanced significantly with the development of the microcalorimeter energy dispersive x-ray spectrometer (mu cal EDS). The mu cal EDS operates by measuring the temperature rise when a single photon is absorbed in a metal target. A cryoelectronic circuit with electrothermal feedback and a superconducting transition edge sensor serves as the thermometer. Spectral resolution approaching 4.5 eV for high energy photons (6000 eV) and 2 eV for low energy photons below 2000 eV has been demonstrated in energy dispersive operation across a photon energy range from 250 eV to 8 keV. Spectra of a variety of materials demonstrate the power of the mu cal EDS to solve practical problems while operating on a scanning electron microscope platform. (author)

X-ray fluorescence spectrometry and related techniques an introduction

CERN Document Server

Margui, Eva

2013-01-01

X-ray fluorescence spectrometry (XRF) is a well-established analytical technique for qualitative and quantitative elemental analysis of a wide variety of routine quality control and research samples. Among its many desirable features, it delivers true multi-element character analysis, acceptable speed and economy, easy of automation, and the capacity to analyze solid samples. This remarkable contribution to this field provides a comprehensive and up-to-date account of basic principles, recent developments, instrumentation, sample preparation procedures, and applications of XRF analysis. If you are a professional in materials science, analytic chemistry, or physics, you will benefit from not only the review of basics, but also the newly developed technologies with XRF. Those recent technological advances, including the design of low-power micro- focus tubes and novel X-ray optics and detectors, have made it possible to extend XRF to the analysis of low-Z elements and to obtain 2D or 3D information on a microme...

Application of high resolution x-ray spectrometry preceded by neutron activation for elemental analysis of soil samples

International Nuclear Information System (INIS)

Hernandez Rivero, A.; Capote Rodriguez, G.; Herrera Peraza, E.

1996-01-01

Utilization of High Resolution X-Ray Spectrometry preceded by activation of the samples by irradiation with neutron fluxes (NAA R X) is a relatively modern trend in application of nuclear techniques. This method may complement advantageously the usual Neutron Activation Analysis by means of Gamma Spectrometry (NAA-G) In this work results obtained by the application of NAA-RX for non-destructive analysis of Cuban soil samples are discussed. The samples were irradiated with reactor neutron fluxes and the induced characteristic X-rays were measured by using Si(li)-detector. Concentrations of Fe, Zn and Eu as determined by NAA-RX are compared with both NAA-G and XRF data. For the elaboration of X-ray and Gamma Spectra the computer programs AXIL and ACTAN were used respectively

Ultrahigh-vacuum in situ electrochemistry with solid polymer electrolyte and x-ray photoelectron spectroscopy studies of polypyrrole

International Nuclear Information System (INIS)

Skotheim, T.A.; Florit, M.I.; Melo, A.; O'Grady, W.E.

1984-01-01

A new in situ combined electrochemistry and x-ray-photoelectron-spectroscopy (XPS) technique using solid polymer electrolytes has been used to characterize electrically conducting films of polypyrrole perchlorate. The technique allows in situ electrochemical oxidation and reduction (doping and undoping) in ultrahigh vacuum and the simultaneous study of the polymer with XPS as a function of its electrochemical potential. We demonstrate that some anion species interact strongly electrostatically with the nitrogen heteroatoms. We also show conclusively that the electrochemistry of polypyrrole is highly irreversible

Forensic application of total reflection X-ray fluorescence spectrometry for elemental characterization of ink samples

International Nuclear Information System (INIS)

Dhara, Sangita; Misra, N.L.; Maind, S.D.; Kumar, Sanjukta A.; Chattopadhyay, N.; Aggarwal, S.K.

2010-01-01

The possibility of applying Total Reflection X-ray Fluorescence for qualitative and quantitative differentiation of documents printed with rare earth tagged and untagged inks has been explored in this paper. For qualitative differentiation, a very small amount of ink was loosened from the printed documents by smoothly rubbing with a new clean blade without destroying the manuscript. 50 μL of Milli-Q water was put on this loose powder, on the manuscript, and was agitated by sucking and releasing the suspension two to three times with the help of a micropipette. The resultant dispersion was deposited on quartz sample support for Total Reflection X-ray Fluorescence measurements. The Total Reflection X-ray Fluorescence spectrum of tagged and untagged inks could be clearly differentiated. In order to see the applicability of Total Reflection X-ray Fluorescence for quantitative determinations of rare earths and also to countercheck such determinations in ink samples, the amounts of rare earth in painted papers with single rare earth tagged inks were determined by digesting the painted paper in HNO 3 /HClO 4 , mixing this solution with the internal standard and recording their Total Reflection X-ray Fluorescence spectra after calibration of the instrument. The results thus obtained were compared with those obtained by Inductively Coupled Plasma Mass Spectrometry and were found in good agreement. The average precision of the Total Reflection X-ray Fluorescence determinations was 5.5% (1σ) and the average deviation of Total Reflection X-ray Fluorescence determined values with that of Inductively Coupled Plasma Mass Spectrometry was 7.3%. These studies have shown that Total Reflection X-ray Fluorescence offers a promising and potential application in forensic work of this nature.

Forensic application of total reflection X-ray fluorescence spectrometry for elemental characterization of ink samples

Energy Technology Data Exchange (ETDEWEB)

Dhara, Sangita [Fuel Chemistry Division, Bhabha Atomic Research Centre, Mumbai 400 085 (India); Misra, N.L., E-mail: nlmisra@barc.gov.i [Fuel Chemistry Division, Bhabha Atomic Research Centre, Mumbai 400 085 (India); Maind, S.D. [NAA Unit of Central Forensic Science Laboratory Hyderabad at Analytical Chemistry Division, Bhabha Atomic Research Centre, Mumbai 400 085 (India); Kumar, Sanjukta A. [Analytical Chemistry Division, Bhabha Atomic Research Centre, Mumbai 400 085 (India); Chattopadhyay, N. [NAA Unit of Central Forensic Science Laboratory Hyderabad at Analytical Chemistry Division, Bhabha Atomic Research Centre, Mumbai 400 085 (India); Aggarwal, S.K. [Fuel Chemistry Division, Bhabha Atomic Research Centre, Mumbai 400 085 (India)

2010-02-15

The possibility of applying Total Reflection X-ray Fluorescence for qualitative and quantitative differentiation of documents printed with rare earth tagged and untagged inks has been explored in this paper. For qualitative differentiation, a very small amount of ink was loosened from the printed documents by smoothly rubbing with a new clean blade without destroying the manuscript. 50 muL of Milli-Q water was put on this loose powder, on the manuscript, and was agitated by sucking and releasing the suspension two to three times with the help of a micropipette. The resultant dispersion was deposited on quartz sample support for Total Reflection X-ray Fluorescence measurements. The Total Reflection X-ray Fluorescence spectrum of tagged and untagged inks could be clearly differentiated. In order to see the applicability of Total Reflection X-ray Fluorescence for quantitative determinations of rare earths and also to countercheck such determinations in ink samples, the amounts of rare earth in painted papers with single rare earth tagged inks were determined by digesting the painted paper in HNO{sub 3}/HClO{sub 4}, mixing this solution with the internal standard and recording their Total Reflection X-ray Fluorescence spectra after calibration of the instrument. The results thus obtained were compared with those obtained by Inductively Coupled Plasma Mass Spectrometry and were found in good agreement. The average precision of the Total Reflection X-ray Fluorescence determinations was 5.5% (1sigma) and the average deviation of Total Reflection X-ray Fluorescence determined values with that of Inductively Coupled Plasma Mass Spectrometry was 7.3%. These studies have shown that Total Reflection X-ray Fluorescence offers a promising and potential application in forensic work of this nature.

X-Ray photoelectron spectroscopy and diffractometry of MnOx catalysts: surface to bulk composition relationships

International Nuclear Information System (INIS)

Zaki, M.I.; Kappenstein, C.

1992-01-01

Surface and bulk analyses of variously-composed, synthetic MnO x catalysts were carried out by means of X-ray photoelectron spectroscopy (XPS) and diffractometry (XRD), respectively. The data obtained were processed for a comprehensive assessment of bulk and surface compositions, surface oxidation state, and crystalline size. The XPS data processing revealed that a credible assessment of the surface composition (MnO x (OH) y (OH 2 ) z necessitates: (i) the implementation of experimental sensitivity factors determined on a local reference surface maintaining a close chemical similarity to the test materials, and (ii) the fine evaluation of contributions of various oxygen-containing surface species to the O 1s electron emission. The most prominent result of the present investigation is that the exposure of the bulk composition at the surface is quite proportioned. Such a surface to bulk intimacy is thought to enable genesizing the surface composition appropriate for certain catalytic and selectivity, via a possible control over the bulk formation events. (orig.)

Elemental analysis of air particulate samples in Jakarta area by x-ray fluorescence spectrometry

International Nuclear Information System (INIS)

Yumiarti; Yusuf, M.; Mellawati, June; Menry, Yulizon; Surtipanti S

1998-01-01

Determination of elements in air particulate samples collected from Jakarta, especially from industrial area Pulo Gadung, also from residence, office, and recreation sites had been carried out. The samples collected periodically from August through December 1996. The elements were analyzed by X-ray fluorescence spectrometry method. Quantitative and qualitative analyses were done using QXAS AXIL (Quantitative X-ray Analysis System of x-ray Spectra by Iterative Least squares fitting) and QAES (Quantitative Analyses of Environmental Samples) package program. Results of the analyses showed that the content of heavy metal elements in air particulate samples from all areas studied were still below the maximum permissible concentration. (authors)

Photoelectron spectroscopy study of the X-ray-induced decomposition of some gold(III) dithiocarbamates

International Nuclear Information System (INIS)

Attekum, P.M.Th.M. van; Trooster, J.M.

1980-01-01

The factors influencing the decomposition rate of two gold(III) complexes, [AuMe 2 (S 2 CNMe 2 )] and [AuBr 2 (S 2 CNPr 2 sup(n))]; in an X-ray photoelectron spectroscopy experiment have been studied. It is shown that the decomposition rate can be slowed down by using graphite as substrate and by lowering the sample temperature. From the Au(4f) spectrum a direct measure has been made of the shift in the binding energy between Ausup(III) and Ausup(I) and this shift is shown to be dependent on the electronegativity of the ligands. The valence bands of the complexes show a narrow Au(5d) band with a spin-orbit splitting of ca. 1.6 eV. (author)

Characterization of the implantation damage in SiO2 with x-ray photoelectron spectroscopy

International Nuclear Information System (INIS)

Ajioka, T.; Ushio, S.

1986-01-01

X-ray photoelectron spectroscopy (XPS) has been applied to characterize the damage introduced into SiO 2 by ion implantation. By measuring the peak width of Si/sub 2p/ from SiO 2 which corresponds to perturbation of the SiO 2 network, good depth profiles of the damage have been obtained for implanted samples and subsequently annealed samples. The results show that the damage distributed more widely than that calculated from energy deposition and that the perturbation of the network is caused not only by radiation damage but also by the existence of impurities in the network. It has been found that the XPS method is effective to understand the atomic structure, and thus, electrical properties of SiO 2

Determination of 4f energy levels for trivalent lanthanide ions in YAlO{sub 3} by X-ray photoelectron spectroscopy

Energy Technology Data Exchange (ETDEWEB)

Shimizu, Yuhei; Ueda, Kazushige, E-mail: kueda@che.kyutech.ac.jp

2016-09-01

A simple method to analyze 4f energy levels of trivalent lanthanide (Ln) ions was demonstrated by conventional X-ray photoelectron spectroscopy (XPS) measurements using Ln ions doped YAlO{sub 3} sintered polycrystalline samples. Although XPS peaks derived from Ln 4f states overlapped with the host's valence band consisting of O 2p states, the difference XPS spectra between Ln doped and non-doped samples showed only the Ln 4f peaks due to the large difference of photoionization cross sections between Ln 4f and O 2p orbitals. The difference spectra showing Ln 4f states were aligned at the valence band maximum (VBM) making use of the peaks of Al 2p inner shells, and the Ln{sup 3+} 4f energy levels referred to the VBM were determined from the Ln{sup 3+} 4f peak energies. The Ln{sup 3+} 4f energy levels obtained by this simple method were in good agreement with those previously obtained by resonant ultraviolet photoelectron spectroscopy measurements using single crystal samples. - Highlights: • Lanthanide (Ln) 4f energy in YAlO{sub 3} was studied by X-ray photoelectron spectroscopy. • The method used differences in photoionization probability between Ln 4f and O 2p. • Ln 4f states were obtained by difference spectra between Ln- and non-doped samples. • Obtained 4f energy levels agreed with those reported by a sophisticated method.

Photoelectron spectroscopy

International Nuclear Information System (INIS)

Price, W.C.

1974-01-01

A survey is given of the development of x-ray and ultraviolet photoelectron spectroscopy. Applications of photoelectron spectroscopy to studies of atomic electronic configurations are discussed, including photoelectron spectra of hydrides isoelectronic with the inert gases; photoelectron spectra of the halogen derivatives of methane; photoelectron spectra of multiple bonded diatomic molecules; spectra and structure of some multiple bonded polyatomic molecules; spectra and structure of triatomic molecules; and methods of orbital assignment of bands in photoelectron spectra. Physical aspects are considered, including intensities; selection rules; dependence of cross section on photoelectron energy; autoionization; angular distribution of photoelectrons; electron-molecule interactions; and transient species. (26 figures, 54 references) (U.S.)

Research and industrial application of x-ray photoelectron spectroscopy (XPS) in Malaysia

International Nuclear Information System (INIS)

Mohd Ambar Yarmo; Abd Razak Daud; Abdul Kariem Arof

2000-01-01

As a developing country, Malaysia is fully committed to research and development especially for industrial development. One of priority fields is advanced materials and surface analysis of such materials is an important aspect in research. Among the tools for surface science analysis is x-ray photoelectron spectroscopy (XPS) which can be considered new to this country. The industrial sector is also keen to solve their problems and developing their products using XPS. The microelectronic and electrical industries are interested in solving problems related to metal-metal joining , gold silica peeling, surface corrosion and surface coating. The glove industry uses XPS to solve problems due to staining and color fading of their products. Research conducted in universities and research institutes that mainly deal with catalysis, membranes for fuel cells, sensors, batteries, corrosion phenomena and interface interaction in coating finds XPS a useful technique for surface studies. Specific examples from various sectors will be presented in this paper. (Author)

Surface characterization of IM7/5260 composites by x-ray photoelectron spectroscopy

International Nuclear Information System (INIS)

Ohno, Satomi; Lee, Moon-Hwan; Lin, Kuen Y.; Ohuchi, Fumio S.

2001-01-01

Surfaces of high-performance carbon fiber/bismeleimide (BMI) composites (IM7/5260) have been characterized by x-ray photoelectron spectroscopy. An experimental technique to separately examine the chemical natures of the carbon fibers and BMI resin in the composite form was developed. This technique uses a flood gun to establish differential charging conditions on the BMI resin. The binding energies from the BMI resin were shifted by an amount of voltage applied to the flood gun, whereas those from the carbon fibers were uniquely determined due to their electrically conducting nature. By adding external bias voltage to the sample, the binding energies for conducting fibers were further shifted from those of the BMI resin, thereby separating the IM7 phase completely from the BMI phase in the binding energy scale, allowing independent measurement of the chemical changes associated with those peaks. Using this technique, the effects of thermal aging and surface plasma treatment on the IM7/5260 composite were studied

X-ray photoelectron spectroscopy study of radiofrequency-sputtered refractory compound steel interfaces

Science.gov (United States)

Wheeler, D. R.; Brainard, W. A.

1978-01-01

Radiofrequency sputtering was used to deposit Mo2C, Mo2B5, and MoSi2 coatings on 440C steel substrates. Both sputter etched and preoxidized substrates were used, and the films were deposited with and without a substrate bias of -300 V. The composition of the coatings was measured as a function of depth by X-ray photoelectron spectroscopy combined with argon ion etching. In the interfacial region there was evidence that bias produced a graded interface in Mo2B5 but not in Mo2C. Oxides of iron and of all film constituents except carbon were presented in all cases but the iron oxide concentration was higher and the layer thicker on the preoxidized substrates. The film and iron oxides were mixed in the MoSi2 and Mo2C films but layered in the Mo2B5 film. The presence of mixed oxides correlates with enhanced film adhesion.

Lab-based ambient pressure X-ray photoelectron spectroscopy from past to present

Science.gov (United States)

Arble, Chris; Jia, Meng; Newberg, John T.

2018-05-01

Chemical interactions which occur at a heterogeneous interface between a gas and substrate are critical in many technological and natural processes. Ambient pressure X-ray photoelectron spectroscopy (AP-XPS) is a powerful spectroscopy tool that is inherently surface sensitive, elemental and chemical specific, with the ability to probe sample surfaces in the presence of a gas phase. In this review, we discuss the evolution of lab-based AP-XPS instruments, from the first development by Siegbahn and coworkers up through modern day systems. A comprehensive overview is given of heterogeneous experiments investigated to date via lab-based AP-XPS along with the different instrumental metrics that affect the quality of sample probing. We conclude with a discussion of future directions for lab-based AP-XPS, highlighting the efficacy for this in-demand instrument to continue to expand in its ability to significantly advance our understanding of surface chemical processes under in situ conditions in a technologically multidisciplinary setting.

Hard X-ray photoelectron spectroscopy of bulk and thin films of Heusler compounds

Energy Technology Data Exchange (ETDEWEB)

Kozina, Xeniya

2012-03-26

X-ray photoemission spectroscopy (XPS) is one of the most universal and powerful tools for investigation of chemical states and electronic structures of materials. The application of hard X-rays increases the inelastic mean free path of the emitted electrons within the solid and thus makes hard X-ray photoelectron spectroscopy (HAXPES) a bulk sensitive probe for solid state research and especially a very effective nondestructive technique to study buried layers. This thesis focuses on the investigation of multilayer structures, used in magnetic tunnel junctions (MTJs), by a number of techniques applying HAXPES. MTJs are the most important components of novel nanoscale devices employed in spintronics. The investigation and deep understanding of the mechanisms responsible for the high performance of such devices and properties of employed magnetic materials that are, in turn, defined by their electronic structure becomes feasible applying HAXPES. Thus the process of B diffusion in CoFeB-based MTJs was investigated with respect to the annealing temperature and its influence on the changes in the electronic structure of CoFeB electrodes that clarify the behaviour and huge TMR ratio values obtained in such devices. These results are presented in chapter 6. The results of investigation of the changes in the valence states of buried off-stoichiometric Co{sub 2}MnSi electrodes were investigated with respect to the Mn content {alpha} and its influence on the observed TMR ratio are described in chapter 7. Magnetoelectronic properties such as exchange splitting in ferromagnetic materials as well as the macroscopic magnetic ordering can be studied by magnetic circular dichroism in photoemission (MCDAD). It is characterized by the appearance of an asymmetry in the photoemission spectra taken either from the magnetized sample with the reversal of the photon helicity or by reversal of magnetization direction of the sample when the photon helicity direction is fixed. Though

X-ray fluorescence and gamma-ray spectrometry combined with multivariate analysis for topographic studies in agricultural soil

International Nuclear Information System (INIS)

Castilhos, Natara D.B. de; Melquiades, Fábio L.; Thomaz, Edivaldo L.; Bastos, Rodrigo Oliveira

2015-01-01

Physical and chemical properties of soils play a major role in the evaluation of different geochemical signature, soil quality, discrimination of land use type, soil provenance and soil degradation. The objectives of the present study are the soil elemental characterization and soil differentiation in topographic sequence and depth, using Energy Dispersive X-Ray Fluorescence (EDXRF) as well as gamma-ray spectrometry data combined with Principal Component Analysis (PCA). The study area is an agricultural region of Boa Vista catchment which is located at Guamiranga municipality, Brazil. PCA analysis was performed with four different data sets: spectral data from EDXRF, spectral data from gamma-ray spectrometry, concentration values from EDXRF measurements and concentration values from gamma-ray spectrometry. All PCAs showed similar results, confirmed by hierarchical cluster analysis, allowing the data grouping into top, bottom and riparian zone samples, i.e. the samples were separated due to its landscape position. The two hillslopes present the same behavior independent of the land use history. There are distinctive and characteristic patterns in the analyzed soil. The methodologies presented are promising and could be used to infer significant information about the region to be studied. - Highlights: • Characterization of topographic sequence of two hillslopes from agricultural soil. • Employment of EDXRF and gamma-ray spectrometry data combined with PCA. • The combination of green analytical methodologies with chemometric studies allowed soil differentiation. • The innovative methodology is promising for direct characterization of agricultural catchments

High resolution X-ray photoelectron spectroscopy of styrene oxide adsorption and reaction on Ag(1 1 1)

Science.gov (United States)

Piao, H.; Enever, M. C. N.; Adib, K.; Hrbek, J.; Barteau, M. A.

2004-11-01

Synchrotron-based X-ray photoelectron spectroscopy (XPS) has been used to investigate the adsorption and reaction of styrene oxide on Ag(1 1 1). When adsorption is carried out at 250 K or above, ring opening of styrene oxide forms a stable surface oxametallacycle intermediate which eventually reacts at 485 K to regenerate styrene oxide. High resolution XPS is capable of distinguishing the oxametallacycle from molecularly adsorbed and condensed styrene oxide on the basis of different C1s peak separations. The observed separations are well accounted for by the results of DFT calculations.

In Situ X-Ray Photoelectron Spectroscopy of Model Catalysts: At the Edge of the Gap

Science.gov (United States)

Blomberg, S.; Hoffmann, M. J.; Gustafson, J.; Martin, N. M.; Fernandes, V. R.; Borg, A.; Liu, Z.; Chang, R.; Matera, S.; Reuter, K.; Lundgren, E.

2013-03-01

We present high-pressure x-ray photoelectron spectroscopy (HP-XPS) and first-principles kinetic Monte Carlo study addressing the nature of the active surface in CO oxidation over Pd(100). Simultaneously measuring the chemical composition at the surface and in the near-surface gas phase, we reveal both O-covered pristine Pd(100) and a surface oxide as stable, highly active phases in the near-ambient regime accessible to HP-XPS. Surprisingly, no adsorbed CO can be detected during high CO2 production rates, which can be explained by a combination of a remarkably short residence time of the CO molecule on the surface and mass-transfer limitations in the present setup.

Evaluation of an automated assay system to measure soil radionuclides by L x-ray and gamma-ray spectrometry

International Nuclear Information System (INIS)

Nyhan, J.W.; Drennon, B.J.; Crowell, J.M.

1982-08-01

An automated radionuclide assay system for conducting soil radioassays using L x-ray and gamma-ray spectrometry was evaluated. Wet chemistry assay procedures were shown to be considerably more time consuming than similar analyses of soil on this radionuclide assay system. The detection limits of 241 Am and plutonium were determined, as well as the reproducibility of radionuclide assay results. The L x-ray spectrometric measurements were compared with radiochemical analyses on several tuff samples. The assay system's intrinsic germanium detector was found to respond linearly to varying low concentrations of 241 Am and plutonium, both of which were easily detected in the presence of elevated concentrations of 137 Cs

Application of high resolution x-ray spectrometry preceded by neutron activation for elemental analysis of soil samples

International Nuclear Information System (INIS)

Hernandez Rivero, A.; Capote Rodriguez, G.; Padilla Alvarez, R.; Herrera Peraza, E.

1997-01-01

Utilization of High Resolution X-Ray Spectrometry preceded by activation of the samples by irradiation with neutron fluxes (NAA-RX) is a relatively modern trend in application of nuclear techniques. This method may complement advantageously the usual Neutron Activation Analysis by means of Gamma Spectrometry (NAA-G). In this work results obtained by the application of NAA-RX for non-destructive analysis of Cuban soil samples are discussed. The samples were irradiated with reactor neutron fluxes and the induced characteristic X-rays were measured by using Si(Li)-detector. Concentrations of Fe, Zn and Eu as determined by NAA-RX are compared with both NAA-G and XRF data. For the elaboration of X-Ray and Gamma Spectra the computer programs AXIL and ACTAN were used respectively. (author) [es

Applications of the Basic programming language in X-ray spectrometry

International Nuclear Information System (INIS)

Diaz-Guerra, J.P.; Roca, M.

1981-01-01

An assembly of programs written in ''Basic'' language and related with the calculation needs at the X-ray spectrometry laboratory of the Spanish J.E.N. has been developed. The principal problems considered, concerning the X-ray fluorescence technique, are the following: selection of the instrumental parameters; correction of the effects due to the dead time, background and spectral interferences; fitting of polynomial functions, which relate the variables intensity-concentration; application of some empirical-mathematical methods (Lucas-Tooth, Beattie and Brissey and Tertian procedures) to the correction of the inter-element effects; addition method, and statistical treatment of the results (correlation coefficient and ''F'' and ''t'' tests). Likewise, programs for the computation of spacings from powder diffraction patterns (Debye-Scherrer and counter diffractometer procedures) have been written. The proposed programs run following conversational patterns, in which different possibilities and incidences have been foreseen. (author)

X-ray photoelectron spectroscopy study of Schottky barrier formation and thermal stability of the LaB6/GaAs(001) c (4 x 4) interface

International Nuclear Information System (INIS)

Yokotsuka, T.; Narusawa, T.; Uchida, Y.; Nakashima, H.

1987-01-01

Schottky barrier formation and thermal stability of the LaB 6 /GaAs(001) c (4 x 4) interface were investigated by x-ray photoelectron spectroscopy. Results show an excellent thermal stability without any appreciable interface reactions such as interdiffusion. Band bending induced by LaB 6 deposition is found to depend on the evaporation condition. However, the Fermi level pinning position does not change due to heat treatments between 300 and 700 0 C. This indicates that LaB 6 is a promising gate material for GaAs integrated circuits

Optimization of measure parameters for an X- and gamma-ray spectrometry portable system

International Nuclear Information System (INIS)

Fernandes, Jaquiel S.; Appoloni, Carlos R.

2008-01-01

In order to optimize the use of a system for in situ gamma (γ)- and X-ray spectrometry composed of a 3x3x1 mm 3 Cadmium Telluride (CdTe) detector with respect to the detection of low-activity radioactive sources, a two level factorial planning was accomplished, involving three factors that could modify the system response. This planning was made with a 137 Cs punctual source, analyzing the X-ray energy line of 32 keV from 137m Ba. It was concluded that, for the system optimization, the best configuration for the involved parameters was to work with the detector at temperature of -22 o C, shaping time of 3 μs and rise time discrimination (RTD) with value 3

Spectroscopic imaging, diffraction, and holography with x-ray photoemission

Energy Technology Data Exchange (ETDEWEB)

1992-02-01

X-ray probes are capable of determining the spatial structure of an atom in a specific chemical state, over length scales from about a micron all the way down to atomic resolution. Examples of these probes include photoemission microscopy, energy-dependent photoemission diffraction, photoelectron holography, and X-ray absorption microspectroscopy. Although the method of image formation, chemical-state sensitivity, and length scales can be very different, these X-ray techniques share a common goal of combining a capability for structure determination with chemical-state specificity. This workshop will address recent advances in holographic, diffraction, and direct imaging techniques using X-ray photoemission on both theoretical and experimental fronts. A particular emphasis will be on novel structure determinations with atomic resolution using photoelectrons.

Spectroscopic imaging, diffraction, and holography with x-ray photoemission

International Nuclear Information System (INIS)

1992-02-01

X-ray probes are capable of determining the spatial structure of an atom in a specific chemical state, over length scales from about a micron all the way down to atomic resolution. Examples of these probes include photoemission microscopy, energy-dependent photoemission diffraction, photoelectron holography, and X-ray absorption microspectroscopy. Although the method of image formation, chemical-state sensitivity, and length scales can be very different, these X-ray techniques share a common goal of combining a capability for structure determination with chemical-state specificity. This workshop will address recent advances in holographic, diffraction, and direct imaging techniques using X-ray photoemission on both theoretical and experimental fronts. A particular emphasis will be on novel structure determinations with atomic resolution using photoelectrons

Effect of iron oxide reductive dissolution on the transformation and immobilization of arsenic in soils: New insights from X-ray photoelectron and X-ray absorption spectroscopy

Energy Technology Data Exchange (ETDEWEB)

Fan, Jian-Xin [Key Laboratory of Soil Environment and Pollution Remediation, Institute of Soil Science, Chinese Academy of Sciences, Nanjing 210008 (China); School of River and Ocean Engineering, Chongqing Jiaotong University, Chongqing 400074 (China); Wang, Yu-Jun, E-mail: yjwang@issas.ac.cn [Key Laboratory of Soil Environment and Pollution Remediation, Institute of Soil Science, Chinese Academy of Sciences, Nanjing 210008 (China); Liu, Cun [Key Laboratory of Soil Environment and Pollution Remediation, Institute of Soil Science, Chinese Academy of Sciences, Nanjing 210008 (China); Wang, Li-Hua; Yang, Ke [Synchrotron Radiation Facility, Shanghai Institute of Applied Physics, Chinese Academy of sciences, Shanghai 201204 (China); Zhou, Dong-Mei, E-mail: dmzhou@issas.ac.cn [Key Laboratory of Soil Environment and Pollution Remediation, Institute of Soil Science, Chinese Academy of Sciences, Nanjing 210008 (China); Li, Wei; Sparks, Donald L. [Environmental Soil Chemistry Group, Delaware Environmental Institute and Department of Plant and Soil Sciences, University of Delaware, Newark, DE 19717-1303 United States (United States)

2014-08-30

Graphical abstract: - Highlights: • Immobility and transformation of As on different Eh soils were investigated. • μ-XRF, XANES, and XPS were used to gain As distribution and speciation in soil. • Sorption capacity of As on anaerobic soil was much higher than that on oxic soil. • Fe oxides reductive dissolution is a key factor for As sorption and transformation. - Abstract: The geochemical behavior and speciation of arsenic (As) in paddy soils is strongly controlled by soil redox conditions and the sequestration by soil iron oxyhydroxides. Hence, the effects of iron oxide reductive dissolution on the adsorption, transformation and precipitation of As(III) and As(V) in soils were investigated using batch experiments and synchrotron based techniques to gain a deeper understanding at both macroscopic and microscopic scales. The results of batch sorption experiments revealed that the sorption capacity of As(V) on anoxic soil was much higher than that on control soil. Synchrotron based X-ray fluorescence (μ-XRF) mapping studies indicated that As was heterogeneously distributed and was mainly associated with iron in the soil. X-ray absorption near edge structure (XANES), micro-X-ray absorption near edge structure (μ-XANES) and X-ray photoelectron spectroscopy (XPS) analyses revealed that the primary speciation of As in the soil is As(V). These results further suggested that, when As(V) was introduced into the anoxic soil, the rapid coprecipitation of As(V) with ferric/ferrous ion prevented its reduction to As(III), and was the main mechanism controlling the immobilization of As. This research could improve the current understanding of soil As chemistry in paddy and wetland soils.

Effect of iron oxide reductive dissolution on the transformation and immobilization of arsenic in soils: New insights from X-ray photoelectron and X-ray absorption spectroscopy

International Nuclear Information System (INIS)

Fan, Jian-Xin; Wang, Yu-Jun; Liu, Cun; Wang, Li-Hua; Yang, Ke; Zhou, Dong-Mei; Li, Wei; Sparks, Donald L.

2014-01-01

Graphical abstract: - Highlights: • Immobility and transformation of As on different Eh soils were investigated. • μ-XRF, XANES, and XPS were used to gain As distribution and speciation in soil. • Sorption capacity of As on anaerobic soil was much higher than that on oxic soil. • Fe oxides reductive dissolution is a key factor for As sorption and transformation. - Abstract: The geochemical behavior and speciation of arsenic (As) in paddy soils is strongly controlled by soil redox conditions and the sequestration by soil iron oxyhydroxides. Hence, the effects of iron oxide reductive dissolution on the adsorption, transformation and precipitation of As(III) and As(V) in soils were investigated using batch experiments and synchrotron based techniques to gain a deeper understanding at both macroscopic and microscopic scales. The results of batch sorption experiments revealed that the sorption capacity of As(V) on anoxic soil was much higher than that on control soil. Synchrotron based X-ray fluorescence (μ-XRF) mapping studies indicated that As was heterogeneously distributed and was mainly associated with iron in the soil. X-ray absorption near edge structure (XANES), micro-X-ray absorption near edge structure (μ-XANES) and X-ray photoelectron spectroscopy (XPS) analyses revealed that the primary speciation of As in the soil is As(V). These results further suggested that, when As(V) was introduced into the anoxic soil, the rapid coprecipitation of As(V) with ferric/ferrous ion prevented its reduction to As(III), and was the main mechanism controlling the immobilization of As. This research could improve the current understanding of soil As chemistry in paddy and wetland soils

Photoelectron diffraction from single oriented molecules: Towards ultrafast structure determination of molecules using x-ray free-electron lasers

Science.gov (United States)

Kazama, Misato; Fujikawa, Takashi; Kishimoto, Naoki; Mizuno, Tomoya; Adachi, Jun-ichi; Yagishita, Akira

2013-06-01

We provide a molecular structure determination method, based on multiple-scattering x-ray photoelectron diffraction (XPD) calculations. This method is applied to our XPD data on several molecules having different equilibrium geometries. Then it is confirmed that, by our method, bond lengths and bond angles can be determined with a resolution of less than 0.1 Å and 10∘, respectively. Differently from any other scenario of ultrafast structure determination, we measure the two- or three-dimensional XPD of aligned or oriented molecules in the energy range from 100 to 200 eV with a 4π detection velocity map imaging spectrometer. Thanks to the intense and ultrashort pulse properties of x-ray free-electron lasers, our approach exhibits the most probable method for obtaining ultrafast real-time structural information on small to medium-sized molecules consisting of light elements, i.e., a “molecular movie.”

X-ray hot plasma diagnostics

International Nuclear Information System (INIS)

Cojocaru, E.

1984-11-01

X-ray plasma emission study is powerful diagnostic tool of hot plasmas. In this review article the main techniques of X-ray plasma emission measurement are shortly presented: X-ray spectrometry using absorbent filters, crystal and grating spectrometers, imaging techniques using pinhole cameras, X-ray microscopes and Fresnel zone plate cameras, X-ray plasma emission calorimetry. Advances in these techniques with examples for different hot plasma devices are also presentes. (author)

Nondestructive analysis of silver in gold foil using synchrotron radiation X-ray fluorescence spectrometry

International Nuclear Information System (INIS)

Kasamatsu, Masaaki; Suzuki, Yasuhiro; Suzuki, Shinichi; Nakanishi, Toshio; Shimoda, Osamu; Nishiwaki, Yoshinori; Miyamoto, Naoki

2005-01-01

Small particles of gold foil detached from an indoor decoration might be important evidence to associate a suspect with a crime scene. We have investigated the application of elemental analysis using synchrotron radiation X-ray fluorescence spectrometry to discriminate small particles of gold foil. Eight kinds of gold foil samples collected in Japan were used in the experiments. As a result of synchrotron radiation X-ray fluorescence spectrometry, only two elements, gold and silver, were detected from all gold foil samples. The intensity ratios of AgK α /AuL α showed good correlation with the content ratios of Ag/Au. The variation of intensity ratio within a same sample was sufficiently small compared with those of different samples. Therefore the comparison of this intensity ratio can be an effective method to discriminate small particles originating from different types of gold foil. (author)

X-ray photoelectron spectroscopy study of the initial oxidation of uranium metal in oxygen+water-vapour mixtures

International Nuclear Information System (INIS)

Allen, G.C.; Tucker, P.M.; Lewis, R.A.

1984-01-01

X-ray photoelectron spectroscopy (X.p.s.) has been used to study the chemical nature of the oxide film initially produced on clean uranium metal in oxygen + water-vapour atmospheres. The rate of reaction has been monitored and the nature of the surface film determined. From a consideration of the O 1s and U 4f X.p. spectra it has been possible to advance a mechanism which explains the complex nature of the surface oxide and the lack of satellite structure in the spectra. This is postulated to be a consequence of the way in which OH - is involved in the growth of the oxide and the presence of hydrogen in the surface film. The presence of oxygen retards the water oxidation reaction by inhibiting the decomposition of water vapour at the gas/oxide interface. (author)

X-ray photoelectron spectroscopy study of the initial oxidation of uranium metal in oxygen+water-vapour mixtures

Energy Technology Data Exchange (ETDEWEB)

Allen, G.C.; Tucker, P.M.; Lewis, R.A. (Central Electricity Generating Board, Berkeley (UK). Berkeley Nuclear Labs.)

1984-08-01

X-ray photoelectron spectroscopy (X.p.s.) has been used to study the chemical nature of the oxide film initially produced on clean uranium metal in oxygen + water-vapour atmospheres. The rate of reaction has been monitored and the nature of the surface film determined. From a consideration of the O 1s and U 4f X.p. spectra it has been possible to advance a mechanism which explains the complex nature of the surface oxide and the lack of satellite structure in the spectra. This is postulated to be a consequence of the way in which OH/sup -/ is involved in the growth of the oxide and the presence of hydrogen in the surface film. The presence of oxygen retards the water oxidation reaction by inhibiting the decomposition of water vapour at the gas/oxide interface.

Auger electron and X-ray photoelectron spectroscopic study of the biocorrosion of copper by alginic acid polysaccharide

Science.gov (United States)

Jolley, John G.; Geesey, Gill G.; Hankins, Michael R.; Wright, Randy B.; Wichlacz, Paul L.

1989-08-01

Thin films (3.4 nm) of copper on germanium substrates were exposed to 2% alginic acid polysaccharide aqueous solution. Pre- and post-exposure characterization were done by Auger electron spectroscopy and X-ray photoelectron spectroscopy. Ancillary graphite furnace atomic absorption spectroscopy was used to monitor the removal process of the copper thin film from the germanium substrate. Results indicate that some of the copper was oxidized by the alginic acid solution. Some of the copper was removed from the Cu/Ge interface and incorporated into the polymer matrix. Thus, biocorrosion of copper was exhibited by the alginic acid polysaccharide.

Evaluation of band alignment of α-Ga2O3/α-(Al x Ga1‑ x )2O3 heterostructures by X-ray photoelectron spectroscopy

Science.gov (United States)

Uchida, Takayuki; Jinno, Riena; Takemoto, Shu; Kaneko, Kentaro; Fujita, Shizuo

2018-04-01

The band alignment at an α-Ga2O3/α-(Al x Ga1‑ x )2O3 heterointerface, with different Al compositions (x), grown on a c-plane sapphire substrate was evaluated by X-ray photoelectron spectroscopy. The experimental results show that the heterointerface has the type-I band discontinuity with the valence band offsets of 0.090, 0.12, and 0.14 eV, and the conduction band offsets of 0.34, 0.79, and 1.87 eV, for x values of 0.1, 0.4, and 0.8, respectively. The small band offset for the valence band is attributed to the fact that the valence band of oxides is constituted by the localized O 2p level, which is dominated by the nature of oxygen atoms. The type-I band discontinuity is desirable for a variety of heterostructure devices.

The surface of 1-euro coins studied by X-ray photoelectron spectroscopy

International Nuclear Information System (INIS)

Gou, F.; Gleeson, M.A.; Villette, J.; Kleyn, S.E.F.; Kleyn, A.W.

2004-01-01

The two alloy surfaces (pill and ring) that are present on 1-euro coins have been studied by X-ray photoelectron spectroscopy (XPS). Comparison is made between coins from general circulation and coin surfaces that have been subjected to a variety of cleaning and oxidation treatments. The concentrations and possible oxidation states of the metals (nickel, copper and zinc) at the surface were derived from analysis of the 2p 3/2 core levels. The surface atomic ratios measured for the pill and the ring parts of the euro coins were compared to the official bulk ratios. This study shows a clear nickel enrichment of both pill and ring surfaces. Nickel at surface seems to be present mainly in hydroxide form although the chloride form cannot be excluded. A small concentration of zinc was present on the surface of the pill, even though it is not present in the bulk alloy. Evidence of both nickel and zinc surface enrichment is observed for the ring. No surface enrichment is observed for the atomically clean or oxidized alloy surfaces over a 60-h time scale

Measurement of ZnO/Al2O3 Heterojunction Band Offsets by in situ X-Ray Photoelectron Spectroscopy

International Nuclear Information System (INIS)

Lei Hong-Wen; Zhang Hong; Wang Xue-Min; Zhao Yan; Yan Da-Wei; Jiang Zhong-Qian; Yao Gang; Zeng Ti-Xian; Wu Wei-Dong

2013-01-01

ZnO films are grown on c-sapphire substrates by laser molecular beam epitaxy. The band offsets of the ZnO/Al 2 O 3 heterojunction are studied by in situ x-ray photoelectron spectroscopy. The valence band of Al 2 O 3 is found to be 3.59±0.05eV below that of ZnO. Together with the resulting conduction band offset of 2.04±0.05eV, this indicates that a type-I staggered band line exists at the ZnO/Al 2 O 3 heterojunction

Analysis of arsenic and some other elements in coal fly ash by X-ray photoelectron spectroscopy

International Nuclear Information System (INIS)

Ohki, Akira; Nakajima, Tsunenori; Sakaguchi, Yuka; Iwashita, Akira; Takanashi, Hirokazu

2005-01-01

Surface characterization of coal fly ash (CFA) was carried out by use of X-ray photoelectron spectroscopy (XPS), especially focusing on the occurrence of As. A peak in the XPS spectrum of CFA was assigned to oxide forms of As(3d). The molar ratios of Al, As, Ca, Fe, and S normalized to Si were obtained from XPS analysis (MR-X). Also, the molar ratios of those elements were calculated from bulk analysis (total element concentration in CFA) (MR-B). The MR-X/MR-B ratio of As was much higher than those of other elements, suggesting that As is highly enriched on the surface of CFA. When eight CFA samples were analyzed, there was an approximate relationship between the MR-X values and MR-B values for As. The leaching of elements from CFA was examined by XPS analysis and by bulk analysis. The leaching tests using EDTA and HNO 3 resulted in a great decrease in the As(3d) peak area; the %leaching of As obtained by XPS analysis was almost equal to that by bulk analysis

X-ray photoelectron emission spectromicroscopic analysis of arborescent lycopsid cell wall composition and Carboniferous coal ball preservation

Energy Technology Data Exchange (ETDEWEB)

Boyce, C. Kevin [Department of the Geophysical Sciences, University of Chicago, Chicago, IL 60637 (United States); Abrecht, Mike; Zhou, Dong; Gilbert, P.U.P.A. [Department of Physics, University of Wisconsin, Madison, WI 53706 (United States)

2010-08-01

Two alternative processes complicate understanding of the biochemical origins and geochemical alteration of organic matter over geologic time: selective preservation of original biopolymers and in situ generation of new geopolymers. One of the best constrained potential sources of bio- and geochemical information about extinct fossil plants is frequently overlooked. Permineralized anatomically preserved plant fossils allow analysis of individual cell and tissue types that have an original biochemical composition already known from living plants. The original composition of more enigmatic fossils can be constrained by geochemical comparisons to tissues of better understood fossils from the same locality. This strategy is possible using synchrotron-based techniques for submicron-scale imaging with X-rays over a range of frequencies in order to provide information concerning the relative abundance of different organic bonds with X-ray Absorption Near Edge Spectroscopy. In this study, X-ray PhotoElectron Emission spectroMicroscopy (X-PEEM) was used to analyze the tissues of Lepidodendron, one of the lycopsid trees that were canopy dominants of many Pennsylvanian coal swamp forests. Its periderm or bark - the single greatest biomass contributor to many Late Paleozoic coals - is found to have a greater aliphatic content and an overall greater density of organic matter than lignified wood. Because X-PEEM allows simultaneous analysis of organic matter and matrix calcite in fully mineralized fossils, this technique also has great potential for analysis of fossil preservation, including documentation of significant traces of organic matter entrained in the calcite crystal fabric that fills the cell lumens. (author)

Thin coating thickness determination using radioisotope-excited x-ray fluorescence spectrometry

International Nuclear Information System (INIS)

Del Castillo, Lorena A.; Calix, Virginia S.

2001-01-01

Three different approaches on thin coating thickness determination using a radioisotope-excited x-ray fluorescence spectrometry were demonstrated and results were compared. A standard of thin layer of gold (Au) on a nickel (Ni) substrate from the US National Bureau of Standards (with a nominal thickness of 0.300505 microns of at least 99.9% Au electrodeposited over 2 nils of Ni) on low carbon steel (1010) was analyzed using a Cd 109-excited XRF system. Au thickness computations were done using the (a) thin standard approach, (b) thick standard approach, and (c) x-ray absorption method (ASTM A754-79 1982). These three methods yielded results within the limit set by the American Society for Testing Materials (ASTM), which is +/-3%. Of the three methods, the thick standard yielded the best result with 0.124% error. (Author)

Infrared and x-ray photoelectron spectroscopic studies on sodium borosilicate glass interacted with thermally oxidized aluminides formed on alloy 690

International Nuclear Information System (INIS)

Yusufali, C.; Dutta, R.S.; Dey, G.K.; Kshirsagar, R.J.; Jagannath; Mishra, R.K.

2012-01-01

Thermally oxidized aluminides formed on Ni-Cr-Fe based superalloy 690 substrates were subjected to interaction with sodium borosilicate melt (used as matrices for immobilization of high-level radioactive liquid waste) at 1248 K for 192 hours. After the interaction, Fourier-transform infrared (FT-IR) spectroscopy analysis of glass samples indicated the incorporation of Al in the glass network. X-ray photoelectron spectroscopy (XPS) of glass specimens revealed modified glass structure. (author)

Oxidation and surface segregation of chromium in Fe–Cr alloys studied by Mössbauer and X-ray photoelectron spectroscopy

International Nuclear Information System (INIS)

Idczak, R.; Idczak, K.; Konieczny, R.

2014-01-01

The room temperature 57 Fe Mössbauer and XPS spectra were measured for polycrystalline iron-based Fe–Cr alloys. The spectra were collected using three techniques: the transmission Mössbauer spectroscopy (TMS), the conversion electron Mössbauer spectroscopy (CEMS) and the X-ray photoelectron spectroscopy (XPS). The combination of these experimental techniques allows to determine changes in Cr concentration and the presence of oxygen in bulk, in the 300 nm pre-surface layer and on the surface of the studied alloys

Analysis of selected elements in tobacco by wavelength dispersive X-ray fluorescence spectrometry

International Nuclear Information System (INIS)

Martin, J.M.

1988-01-01

A rapid method for the determination of 16 elements in tobacco by wavelength dispersive X-ray fluorescence spectrometry has been developed. The method is accurate and precise, and requires only 9 min per sample for quantitation. Sample preparation consists of placing a portion of dried, ground tobacco in a sample cup, and pressing at 25 tons pressure to make a compressed pellet. This pellet is then automatically analyzed by X-ray fluorescence for 16 elements. The results are stored on a computer disk for future recall and report generation. The elements are: Al, Br, Ca, Cl, Cu, Fe, K, Mg, Mn, Na, P, S, Si, Sr, Ti and Zn

X-ray spectrometry induced by electron and proton bombardment: Two complementary techniques for the micro-characterization of mineral materials

International Nuclear Information System (INIS)

Remond, G.; Gilles, C.; Isabelle, D.; Choi, C.G.; Rouer, O.; Cesbron, F.; Yang, C.

1994-01-01

Spatially resolved quantitative analysis by means of the Electron Probe Micro Analyser (EPMA) is now well established as a routine analytical method for point chemical analysis of a variety of mineral materials. Modern computer controlled EPMA are most often equipped with wavelength dispersive spectro- meters (WDS). Quantitative analyses are generally carried out according to a standard based approach, i. e, the x-ray intensities measured at the surface of the unknowns are normalized to those measured at the surface of reference specimens. By the use of energy dispersive spectrometry (EDS) a standardless quantitative based method is preferred when the incident beam current is not accurately known as for the case of EDS analysis coupled to Scanning Electron Microscopy (SEM). The accuracy of point analysis by means of electron beam induced x-ray spectrometry is discussed emphasizing the x-ray photon interactions respectively.The continuous x-ray emission is the physical limit of detection. The excitation conditions must be optimised in order to obtain the higher peak to continuous emission intensity ratios for each element within the matrix. Proton Induced X-ray Emission (PIXE) complements this electron induced x-ray emission for the localization of elements present at trace levels. The experimental procedure used for quantitative analysis by means of PIXE is illustrated emphasizing the use of a limited number of reference materials for deriving quantitative data from the raw PIXE spectra. The complementarity of EMPA/SEM and PIXE techniques is illustrated for the case of rare-earth elements (REE) bearing natural and synthetic doped zircon crystals (Si Zr O sub 4). For such compounds x-ray spectra are very complex because of the existence of severe peak overlaps between the L x-ray emission spectra of the REE. It is shown that cathodoluminescence (EPLA:SEM) and ionoluminescence (PIXE) may be an original alternative approach to x-ray spectrometry for studying REE

Design and fabrication of soft x-ray mirrors

Energy Technology Data Exchange (ETDEWEB)

Kawata, Masaru; Sasai, Hiroyuki; Sano, Kazuo [Shimadzu Corp., Production Engineering Laboratory, Kyoto (Japan)

2000-03-01

Soft x-ray photoelectron spectroscopic technology is important for measuring the chemical status of material surface in the LSI manufacturing process. We report on non-spherical mirrors focusing laser-induced plasma soft x-ray to fine sample surface. We designed toric and ellipsoidal mirror as soft x-ray condensing means, simulated focusing image, manufactured mirror surface on fused quartz substrate, and measured form accuracy. (author)

In situ SERS and X-ray photoelectron spectroscopy studies on the pH-dependant adsorption of anthraquinone-2-carboxylic acid on silver electrode

Energy Technology Data Exchange (ETDEWEB)

Li, Dan, E-mail: dany@sit.edu.cn [School of Chemical and Environmental Engineering, Shanghai Institute of Technology, 100 Haiquan Road, Shanghai 201418 (China); Jia, Shaojie [School of Chemical and Environmental Engineering, Shanghai Institute of Technology, 100 Haiquan Road, Shanghai 201418 (China); Fodjo, Essy Kouadio [Laboratory of Physical Chemistry, University Felix Houphouet Boigny, 22 BP 582, Abidjan 22, Cote d’Ivoire (Cote d' Ivoire); Xu, Hu [School of Chemical and Environmental Engineering, Shanghai Institute of Technology, 100 Haiquan Road, Shanghai 201418 (China); Wang, Yuhong, E-mail: yuhong_wang502@sit.edu.cn [School of Chemical and Environmental Engineering, Shanghai Institute of Technology, 100 Haiquan Road, Shanghai 201418 (China); Deng, Wei [School of Chemical and Environmental Engineering, Shanghai Institute of Technology, 100 Haiquan Road, Shanghai 201418 (China)

2016-03-30

Graphical abstract: The orientation of anthraquinone-2-carboxylic acid (AQ-2-COOH) has been investigated by in situ surface-enhanced Raman scattering (in situ SERS) spectroelectrochemistry and angle-resolved X-ray photoelectron spectroscopy (AR-XPS) on silver surface. - Highlights: • The adsorption behavior of anthraquinone-2-carboxylic acid (AQ-2-COOH) on Ag electrode is influenced by the pH. • The pH-dependant adsorption of AQ-2-COOH has been confirmed by in situ surface-enhanced Raman scattering (in situ SERS) spectroelectrochemistry and angle-resolved X-ray photoelectron spectroscopy (AR-XPS). • The results can provide insights into electron transfer reactions of AQ-2-COOH in biological systems. - Abstract: In this study, in situ surface-enhanced Raman scattering (SERS) spectroelectrochemistry and angle-resolved X-ray photoelectron spectroscopy (AR-XPS) are used to investigate the redox reaction and adsorption behavior of anthraquinone-2-carboxylic acid (AQ-2-COOH) on an Ag electrode at different pH values. The obtained results indicate that AQ-2-COOH is adsorbed tilted on the Ag electrode through O-atom of ring carbonyl in a potential range from −0.3 to −0.5 V vs. SCE, but the orientation turns to more tilted orientation with both O-atom of the ring carbonyl and carboxylate group in positive potential region for pH 6.0 and 7.4. However, at pH 10.0, the orientation adopts tilted conformation constantly on the Ag electrode with both O-atom of the anthraquinone ring and carboxylate group in the potential range from −0.3 to −0.5 V vs. SCE or at positive potentials. Moreover, the adsorption behavior of AQ-2-COOH has been further confirmed by AR-XPS on the Ag surface. Proposed reasons for the observed changes in orientation are presented.

Analysis of electronic structure of amorphous InGaZnO/SiO2 interface by angle-resolved X-ray photoelectron spectroscopy

International Nuclear Information System (INIS)

Ueoka, Y.; Ishikawa, Y.; Maejima, N.; Matsui, F.; Matsui, H.; Yamazaki, H.; Urakawa, S.; Horita, M.; Daimon, H.; Uraoka, Y.

2013-01-01

The electronic structures of amorphous indium gallium zinc oxide (a-IGZO) on a SiO 2 layers before and after annealing were observed by constant final state X-ray photoelectron spectroscopy (CFS-XPS) and X-ray adsorption near-edge structure spectroscopy (XANES). From the results of angle-resolved CFS-XPS, the change in the electronic state was clearly observed in the a-IGZO bulk rather than in the a-IGZO/SiO 2 interface. This suggests that the electronic structures of the a-IGZO bulk strongly affected the thin-film transistor characteristics. The results of XANES indicated an increase in the number of tail states upon atmospheric annealing (AT). We consider that the increase in the number of tail states decreased the channel mobility of AT samples

X-ray Spectrometry: Basic principles

International Nuclear Information System (INIS)

Carvalho, R.M.; Teixeira, G.J.; Cardoso, R.S.; Peixoto, J.G.P.

2017-01-01

The application of X rays requires a study of its spectrum. Intrinsic difficulties of the own method and of all the instrumentation necessary for the accomplishment of this practice were related. The objective was to demonstrate the use of a commercial spectrometer using at room temperature and compare it with spectra theoretically obtained by simulation. As an initial result was that both instrumentation is compatible to be used in an X-ray beam, with and without scattering material and its theoretical data were obtained. (author)

Rare earth aerosol analysis by x-ray fluorescence spectrometry

International Nuclear Information System (INIS)

Citron, I.M.; Mausner, L.F.

1982-01-01

An analytical method for the determination of four lanthanides in air filter samples is described. The method involves simultaneous quantitative determinations of La, Ce, Pr, and Nd at the microgram level by x-ray fluorescence spectrometry without chemical separation of these rare earths and without serious interferences from the dust matrices on the filters. The method has been used successfully to analyze some air filter samples collected at a rare earth processing refinery in Illinois. A description of the development of the method is given as well as the results obtained by using this method on the air filter samples. The reproducibility of the results was generally +-5%

Single-Shot Spectrometry for X-Ray Free-Electron Lasers

International Nuclear Information System (INIS)

Yabashi, Makina; Ishikawa, Tetsuya; Hastings, Jerome B.; Zolotorev, Max S.; Mimura, Hidekazu; Yumoto, Hirokatsu; Matsuyama, Satoshi; Yamauchi, Kazuto

2006-01-01

An experimental scheme to realize single-shot spectrometry for the diagnostics of x-ray free-electron lasers (XFELs) is presented. The combination of an ultraprecisely figured mirror and a perfect crystal form a simple, high-precision spectrometer that can cover an energy range from a few eV to a hundred eV with high resolution. The application of the spectrometer to determine XFEL pulse widths was investigated theoretically and experimentally. It has been shown that the present system can determine pulse widths from sub-fs to ps in a single shot even for spontaneous radiation. The system can be easily extended to even shorter pulses

X-ray photoelectron spectra structure and chemical bonding in AmO2

Directory of Open Access Journals (Sweden)

Teterin Yury A.

2015-01-01

Full Text Available Quantitative analysis was done of the X-ray photoelectron spectra structure in the binding energy range of 0 eV to ~35 eV for americium dioxide (AmO2 valence electrons. The binding energies and structure of the core electronic shells (~35 eV-1250 eV, as well as the relativistic discrete variation calculation results for the Am63O216 and AmO8 (D4h cluster reflecting Am close environment in AmO2 were taken into account. The experimental data show that the many-body effects and the multiplet splitting contribute to the spectral structure much less than the effects of formation of the outer (0-~15 eV binding energy and the inner (~15 eV-~35 eV binding energy valence molecular orbitals. The filled Am 5f electronic states were shown to form in the AmO2 valence band. The Am 6p electrons participate in formation of both the inner and the outer valence molecular orbitals (bands. The filled Am 6p3/2 and the O 2s electronic shells were found to make the largest contributions to the formation of the inner valence molecular orbitals. Contributions of electrons from different molecular orbitals to the chemical bond in the AmO8 cluster were evaluated. Composition and sequence order of molecular orbitals in the binding energy range 0-~35 eV in AmO2 were established. The experimental and theoretical data allowed a quantitative scheme of molecular orbitals for AmO2, which is fundamental for both understanding the chemical bond nature in americium dioxide and the interpretation of other X-ray spectra of AmO2.

Study of electron beam effects on surfaces using x-ray photoelectron spectroscopy (XPS) and secondary ion mass spectroscopy (SIMS)

International Nuclear Information System (INIS)

Gettings, M.; Coad, J.P.

1976-02-01

Discrepancies in the surface analyses of oxidised or heavily contaminated materials have been observed between X-ray Photoelectron Spectroscopy (XPS) and techniques using electron beams (primarily Auger Electron Spectroscopy (AES)). These discrepancies can be ascribed to the influence of the primary electron beam and to illustrate the various types of electron effects different materials were analysed using XPS and Secondary Ion Mass Spectroscopy (SIMS) before and after large area electron bombardment. The materials used included chrome and stainless steels, nickel, platinum, glass and brass. (author)

Non-destructive determination of ultra-thin GaN cap layer thickness in AlGaN/GaN HEMT structure by angle resolved x-ray photoelectron spectroscopy (ARXPS)

Science.gov (United States)

Goyal, Anshu; Yadav, Brajesh S.; Raman, R.; Kapoor, Ashok K.

2018-02-01

Angle resolved X-ray photoelectron spectroscopy (ARXPS) and secondary ion mass spectrometry (SIMS) investigations have been carried out to characterize the GaN cap layer in AlGaN/GaN HEMT structure. The paper discusses the qualitative (presence or absence of a cap layer) and quantitative (cap layer thickness) characterization of cap layer in HEMT structure non-destructively using ARXPS measurements in conjunction with the theoretical modeling. Further the relative sensitive factor (RSF=σ/Ga σAl ) for Ga to Al ratio was estimated to be 0.963 and was used in the quantification of GaN cap layer thickness. Our results show that Al/Ga intensity ratio varies with the emission angle in the presence of GaN cap layer and otherwise remains constant. Also, the modeling of this intensity ratio gives its thickness. The finding of ARXPS was also substantiated by SIMS depth profiling studies.

Non-destructive determination of ultra-thin GaN cap layer thickness in AlGaN/GaN HEMT structure by angle resolved x-ray photoelectron spectroscopy (ARXPS

Directory of Open Access Journals (Sweden)

Anshu Goyal

2018-02-01

Full Text Available Angle resolved X-ray photoelectron spectroscopy (ARXPS and secondary ion mass spectrometry (SIMS investigations have been carried out to characterize the GaN cap layer in AlGaN/GaN HEMT structure. The paper discusses the qualitative (presence or absence of a cap layer and quantitative (cap layer thickness characterization of cap layer in HEMT structure non-destructively using ARXPS measurements in conjunction with the theoretical modeling. Further the relative sensitive factor (RSF=σGaσAl for Ga to Al ratio was estimated to be 0.963 and was used in the quantification of GaN cap layer thickness. Our results show that Al/Ga intensity ratio varies with the emission angle in the presence of GaN cap layer and otherwise remains constant. Also, the modeling of this intensity ratio gives its thickness. The finding of ARXPS was also substantiated by SIMS depth profiling studies.

Sample positioning effects in x-ray spectrometry

International Nuclear Information System (INIS)

Carpenter, D.

Instrument error due to variation in sample position in a crystal x-ray spectrometer can easily exceed the total instrumental error. Lack of reproducibility in sample position in the x-ray optics is the single largest source of system error. The factors that account for sample positioning error are described, and many of the details of flat crystal x-ray optics are discussed

Multichannel, sequential or combined X-ray spectrometry

International Nuclear Information System (INIS)

Florestan, J.

1979-01-01

X-ray spectrometer qualities and defects are evaluated for sequential and multichannel categories. Multichannel X-ray spectrometer has time-coherency advantage and its results could be more reproducible; on the other hand some spatial incoherency limits low percentage and traces applications, specially when backgrounds are very variable. In this last case, sequential X-ray spectrometer would find again great usefulness [fr

X-ray photoelectron spectroscopy applied to the characterization of surfaces at pressures of up to 0.1 mbar

International Nuclear Information System (INIS)

Kong, C.W.

1987-01-01

The thesis describes the design principles, operation and an X-Ray Photoelectron Spectrometer capable of analyzing surfaces under in situ conditions in the pressure range of 10 -11 to 1 mbar. Measurements at pressures exceeding 10 -5 mbar are carried out by placing a differentially pumped aperture system between sample surface and the hemispherical electron energy analyzer. The reduction of signal intensity due to the aperture is, depending on the operating mode and resolution of the analyzer, between a factor of 5-12. Measurements at pressures as high as 6 x 10 -1 mbar show that the sensitivity of the apparatus is sufficient to detect coverages as low as ∼.1 monolayers. The experimental work described in this thesis relates to the interaction of sulfur dioxide with metallic copper and CuO and Cu 2 O surfaces. Adsorption and reaction of SO 2 with these surfaces comprise one of the elemental steps in the flue gas cleanup process from a duct stream using copper oxide particles. The adsorption and reaction of SO 2 with copper and copper oxide surfaces was studied by in situ x-ray photoelectron spectroscopy between 173 K-473 K and pressures ranging from UHV to 10 -1 mbar. It was found that a Cu 2 SO 3 species acts as an intermediate in the formation of CuSO 4 at T 300 K, in the formation of copper sulfide. The presence of gas phase oxygen was found to accelerate the surface reaction between SO 2 and the substrates. Contrary to previous suggestions, the author finds that a copper sulfate is found only under conditions which are far removed form the conditions in a duct-pipe. Under temperature and partial pressure conditions resembling the industrial process, a copper sulfide is formed

Characterization of an Yb:LuVO{sub 4} single crystal using X-ray topography, high-resolution X-ray diffraction, and X-ray photoelectron spectroscopy

Energy Technology Data Exchange (ETDEWEB)

Paszkowicz, W., E-mail: paszk@ifpan.edu.pl [Institute of Physics, Polish Academy of Sciences, al. Lotnikow 32/46, PL-02668 Warsaw (Poland); Romanowski, P.; Bak-Misiuk, J. [Institute of Physics, Polish Academy of Sciences, al. Lotnikow 32/46, PL-02668 Warsaw (Poland); Wierzchowski, W. [Institute of Electronic Materials Technology, Wolczynska 133, PL-01919 Warsaw (Poland); Wieteska, K. [Institute of Atomic Energy POLATOM, PL-05400 Otwock-Swierk (Poland); Graeff, W. [HASYLAB at DESY, Notkestr. 85, D-22603 Hamburg (Germany); Iwanowski, R.J. [Institute of Physics, Polish Academy of Sciences, al. Lotnikow 32/46, PL-02668 Warsaw (Poland); Heinonen, M.H. [Laboratory of Materials Science, Department of Physics, University of Turku, Vesilinnantie 5, FI-20014, Turku (Finland); Ermakova, O. [Institute of Physics, Polish Academy of Sciences, al. Lotnikow 32/46, PL-02668 Warsaw (Poland); Dabkowska, H. [Department of Physics, McMaster University, Hamilton, Ontario, L8S 4M1 (Canada)

2011-10-15

Knowledge on the defect and electronic structure allows for improved modeling of material properties. A short literature review has shown that the information on defect structure of rare earth orthovanadate single crystals is limited. In this paper, defect and electronic structure of a needle-shaped Yb:LuVO{sub 4} single crystal grown by the slow cooling method have been studied by means of X-ray diffraction topography employing white synchrotron beam, high-resolution diffraction (HRD) and photoelectron spectroscopy (XPS) techniques. Topographic investigations show that the crystal is composed of two blocks disoriented by about 1.5{sup o} and separated by a narrow deformed region. Some contrasts observed within the crystal volume may be attributed to glide bands and sector boundaries. The contrasts appearing in the vicinity of the surface may be interpreted as due to the presence of small inclusions. The HRD study indicates, in particular, that among point defects, the vacancy type defects dominate and that the density of other defects is small in comparison. The XPS measurements enabled, despite highly insulating properties of the studied crystal, an analysis of its bulk electronic structure, including the main core-levels (O 1s, V 2p, Lu 4f) as well as the valence band range.

Boron Doped diamond films as electron donors in photovoltaics: An X-ray absorption and hard X-ray photoemission study

Energy Technology Data Exchange (ETDEWEB)

Kapilashrami, M.; Zegkinoglou, I. [Advanced Light Source, Lawrence Berkeley National Laboratory, Berkeley, California 94720 (United States); Department of Physics, University of Wisconsin Madison, Madison, Wisconsin 53706 (United States); Conti, G.; Nemšák, S.; Conlon, C. S.; Fadley, C. S. [Department of Physics, University of California, Davis, California 95616 (United States); Materials Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720 (United States); Törndahl, T.; Fjällström, V. [Ångström Solar Center, Uppsala University, Box 534, SE-751 21 Uppsala (Sweden); Lischner, J. [Department of Physics, University of California, Berkeley, California 94720 (United States); Louie, Steven G. [Materials Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720 (United States); Department of Physics, University of California, Berkeley, California 94720 (United States); Hamers, R. J.; Zhang, L. [Department of Chemistry, University of Wisconsin Madison, Madison, Wisconsin 53706 (United States); Guo, J.-H. [Advanced Light Source, Lawrence Berkeley National Laboratory, Berkeley, California 94720 (United States); Himpsel, F. J., E-mail: fhimpsel@wisc.edu [Department of Physics, University of Wisconsin Madison, Madison, Wisconsin 53706 (United States)

2014-10-14

Highly boron-doped diamond films are investigated for their potential as transparent electron donors in solar cells. Specifically, the valence band offset between a diamond film (as electron donor) and Cu(In,Ga)Se₂ (CIGS) as light absorber is determined by a combination of soft X-ray absorption spectroscopy and hard X-ray photoelectron spectroscopy, which is more depth-penetrating than standard soft X-ray photoelectron spectroscopy. In addition, a theoretical analysis of the valence band is performed, based on GW quasiparticle band calculations. The valence band offset is found to be small: VBO=VBM{sub CIGS} – VBM{sub diamond}=0.3 eV±0.1 eV at the CIGS/Diamond interface and 0.0 eV±0.1 eV from CIGS to bulk diamond. These results provide a promising starting point for optimizing the band offset by choosing absorber materials with a slightly lower valence band maximum.

Oxidation of nanostructured Ti films produced by low energy cluster beam deposition: An X-ray Photoelectron Spectroscopy characterization

International Nuclear Information System (INIS)

Simone, Monica de; Snidero, Elena; Coreno, Marcello; Bongiorno, Gero; Giorgetti, Luca; Amati, Matteo; Cepek, Cinzia

2012-01-01

We used in-situ X-ray Photoelectron Spectroscopy (XPS) to study the oxidation process of a cluster-assembled metallic titanium film exposed to molecular oxygen at room temperature. The nanostructured film has been grown on a Si(111) substrate, in ultra high vacuum conditions, by coupling a supersonic cluster beam deposition system with an XPS experimental chamber. Our results show that upon in-situ oxygen exposure Ti 3+ is the first oxidation state observed, followed by Ti 4+ , whereas Ti 2+ is practically absent during the whole process. Our results compare well with the existing literature on Ti films produced using other techniques.

Valence band offset of wurtzite InN/SrTiO3 heterojunction measured by x-ray photoelectron spectroscopy

Directory of Open Access Journals (Sweden)

Li Zhiwei

2011-01-01

Full Text Available Abstract The valence band offset (VBO of wurtzite indium nitride/strontium titanate (InN/SrTiO3 heterojunction has been directly measured by x-ray photoelectron spectroscopy. The VBO is determined to be 1.26 ± 0.23 eV and the conduction band offset is deduced to be 1.30 ± 0.23 eV, indicating the heterojunction has a type-I band alignment. The accurate determination of the valence and conduction band offsets paves a way to the applications of integrating InN with the functional oxide SrTiO3.

X-ray photoelectron spectroscopy and paramagnetic resonance evidence for shock-induced intramolecular bond breaking in some energetic solids

Science.gov (United States)

Owens, F. J.; Sharma, J.

1980-03-01

Solid samples of 1,3,5, trinitro 1,3,5, triazacyclohexane (RDX), trinitrotoluene (TNT), and ammonium nitrate were subjected to shock pulses of strength and duration less than the threshold to cause detonation. The recovered shocked samples were studied by x-ray photoelectron spectroscopy (XPS) and electron paramagnetic resonance (EPR). The results of these measurements indicate that the shock pulse either broke or altered the internal bonds of the molecules of the solid. The results of the shock decomposition are compared with measurements of the uv and slow thermal decomposition of these materials using the same experimental techniques.

X-ray photoelectron spectroscopy studies of hard coatings formed by titanium on 304 stainless steel

International Nuclear Information System (INIS)

Nair, M.R.; Kothari, D.C.; Rangwala, A.A.; Lal, K.B.; Prabhawalkar, P.D.; Raole, P.M.

1986-01-01

Titanium ions are implanted (at 30 keV) in 304 stainless steel to a dose of 1.8x10 17 ions cm -2 using 15 μA cm -2 and 5 μA cm -2 beam current densities for specimens 2 and 3 respectively. X-ray photoelectron spectroscopy (XPS) measurements are performed at different temperatures. The microhardness of implanted and unimplanted specimens is also measured. In specimen 2 the microhardness does not increase significantly and XPS measurements give evidence of carburized surface alloy formation. At 250 0 C TiO 2 is detected on the surface and it migrates into the bulk phase above 350 0 C. In specimen 3 the XPS measurements exhibit an absence of iron owing to the radiation-induced segregation of titanium on the surface. This specimen shows an increase in microhardness. The XPS measurements reveal a layer of (TiC x -C) on the surface which is suggested to be responsible for the increase in microhardness. Upon heating, TiC x is seen to move into the bulk phase and the carbon concentration is increased. These changes occurring at higher temperatures are suggested as having an effect on the wear-resistant properties of titanium-implanted 304 stainless steel. (orig.)

X-ray fluorescence analysis and optical emission spectrometry of an roman mirror from Tomis, Romania

International Nuclear Information System (INIS)

Belc, M.; Bogoi, M.; Ionescu, D.; Guita, D.; Caiteanu, S.; Caiteanu, D.

2000-01-01

The miscellaneous population of Roman Empire, their diverse cultural tradition, their ability to assimilate the roman civilization spirits, had determined a permanent reassessment superimposed upon the roman contribution. Analysis was undertaken using optical emission spectrometry and non-destructive X-ray fluorescence. X-ray fluorescence analysis is a well-established method and is often used in archaeometry and other work dealing with valuable objects pertaining to the history of art and civilization. Roman mirror analysed has been found not to be made of speculum (a high tin bronze). (authors)

Application of the Auger and X-ray photoelectron electronic spectroscopies to the study of superficial segregation in the system Pt-Rh

International Nuclear Information System (INIS)

Volpe, M.A.; Castellani, N.J.; Leroy, D.B.

1987-01-01

The Auger and X-ray photoelectron spectroscopies are applied to the study of the superficial segregation in the system of the binary alloy Pt-Rh. The methodology for the cleaning of the samples, which is essential for the obtainment of reproducible results, has been established. The spectra qualitative analysis allows to identify the element segregated. The application of the Gallon model permits to develop a quantitative study of the phenomenon. (S.M.) [es

Tuning the Two-Dimensional Electron Gas at Oxide Interfaces with Ti-O Configurations: Evidence from X-ray Photoelectron Spectroscopy

DEFF Research Database (Denmark)

Zhang, Yu; Gan, Yulin; Niu, Wei

2018-01-01

Chemical redox reaction can lead to a two-dimensional electron gas (2DEG) at the interface between a TiO2-terminated SrTiO3 (STO) substrate and an amorphous LaAlO3 (a-LAO) capping layer. When replacing the STO substrate with rutile and anatase TiO2 substrates, considerable differences...... in interfacial conduction are observed. Based on X-ray photoelectron spectroscopy (XPS) and transport measurements, we conclude that the interfacial conduction comes from redox reactions, and that the differences among the materials systems result mainly from variations in the activation energies...

Applied gamma-ray spectrometry

CERN Document Server

Dams, R; Crouthamel, Carl E

1970-01-01

Applied Gamma-Ray Spectrometry covers real life application of the gamma-ray and the devices used in their experimental studies. This book is organized into 9 chapters, and starts with discussions of the various decay processes, the possible interaction mechanisms of gamma radiation with matter, and the intrinsic and extrinsic variables, which affect the observed gamma-ray and X-ray spectra. The subsequent chapters deal with the properties and fabrication of scintillation detectors, semiconductor detectors, and proportional gas counters. These chapters present some of the most widely utilized

Case Studies on Facility Characterization with X-Ray Fluorescence Spectrometry

International Nuclear Information System (INIS)

Kirk, K.T.; Brooksbank, R.D.; Meszaros, J.M.; Towery, W.E.

2008-01-01

A hand-held x-ray fluorescence (XRF) analyzer is being used to characterize facilities in support of demolition activities at the East Tennessee Technology Park (ETTP) in Oak Ridge, Tennessee. Approximately 500 facilities at the U.S. Department of Energy site are being demolished under the ETTP Decontamination and Decommissioning (D and D) project. Facility characterization is being conducted to provide data for waste profiling and identify hazards to demolition workers. XRF spectrometry is a non-destructive analytical technique used to identify and quantify the elemental composition of a substance based on the intensity of its characteristic X-ray emission wavelength or energy. The Innov-X Systems R Model XT-245S XRF analyzer used at ETTP is equipped with a silver anode x-ray tube and a Si PIN diode detector. X-rays are generated by electrical current, eliminating the need for radioactive isotopes. Electronic components can be powered by either a lithium-ion battery or an A/C adapter, and the instrument is controlled by an iPAQ R pocket personal computer. The unit has two primary operating modes. Alloy analysis mode measures percent levels of elements in metals such as a pipes, valves, equipment, or construction materials. Soil mode provides parts-per-million (ppm) quantities in bulk solids like concrete dust, residue, paint chips, or soil. The hand-held unit can analyze material in place, or it can analyze samples in a test stand by remote operation. This paper present some case studies demonstrating a variety of XRF applications for facility characterization: Metal Materials Characterization, Lead Paint Identification, Hot Spot Delineation, Bulk Solids Testing. XRF has been the analytical technique of choice for identifying metal alloy components and has also been useful in analyzing bulk materials. Limitations of XRF testing include the inability to directly analyze elements with low atomic weights. Light elements such as beryllium and aluminum do not emit

Attosecond time-energy structure of X-ray free-electron laser pulses

Science.gov (United States)

Hartmann, N.; Hartmann, G.; Heider, R.; Wagner, M. S.; Ilchen, M.; Buck, J.; Lindahl, A. O.; Benko, C.; Grünert, J.; Krzywinski, J.; Liu, J.; Lutman, A. A.; Marinelli, A.; Maxwell, T.; Miahnahri, A. A.; Moeller, S. P.; Planas, M.; Robinson, J.; Kazansky, A. K.; Kabachnik, N. M.; Viefhaus, J.; Feurer, T.; Kienberger, R.; Coffee, R. N.; Helml, W.

2018-04-01

The time-energy information of ultrashort X-ray free-electron laser pulses generated by the Linac Coherent Light Source is measured with attosecond resolution via angular streaking of neon 1s photoelectrons. The X-ray pulses promote electrons from the neon core level into an ionization continuum, where they are dressed with the electric field of a circularly polarized infrared laser. This induces characteristic modulations of the resulting photoelectron energy and angular distribution. From these modulations we recover the single-shot attosecond intensity structure and chirp of arbitrary X-ray pulses based on self-amplified spontaneous emission, which have eluded direct measurement so far. We characterize individual attosecond pulses, including their instantaneous frequency, and identify double pulses with well-defined delays and spectral properties, thus paving the way for X-ray pump/X-ray probe attosecond free-electron laser science.

X ray photoelectron spectroscopy (XPS) analysis of Photosensitive ZrO2 array

Science.gov (United States)

Li, Y.; Zhao, G.; Zhu, R.; Kou, Z.

2018-03-01

Based on organic zirconium source as the starting material, by adding chemical modifiers which are made up with photosensitive ZrO2 sol. A uniformed ZrO2 array dot was fabricated with a mean diameter of around 800 nm. By using UV-vis spectra and X-ray photoelectron spectroscopy analysis method, studies the photosensitive ZrO2 gel film of photochemical reaction process and the photosensitive mechanism, to determine the zirconium atom centered chelate structure, reaction formed by metal chelate Zr atom for the center, and to establish the molecular model of the chelate. And studied the ultraviolet light in the process of the variation of the XPS spectra, Zr3d5/2 to 184.9 eV corresponding to the binding energy of the as the combination of state peak gradually reduce; By combining with the status of Zr-O peak gradually increase; The strength of the peak is gradually decline. This suggests that in the process of ultraviolet light photo chemical reaction happened. This study is of great significance to the micro fabrication of ZrO2 array not only to the memory devices but also to the optical devices.

Design and characterization for absolute x-ray spectrometry in the 100-10,000 eV region

International Nuclear Information System (INIS)

Henke, B.L.

1986-08-01

Reviewed here are the design and characterization procedures used in our program for developing absolute x-ray spectrometry in the 100 to 10,000 eV region. Described are the selection and experimental calibration of the x-ray filters, mirror momochromators, crystal/multilayer analyzers, and the photographic (time integrating) and photoelectric (time resolving) position-sensitive detectors. Analytical response functions have been derived that characterize the energy dependence of the mirror and crystal/multilayer reflectivities and of the photographic film and photocathode sensitivities. These response functions permit rapid, small-computer reduction of the experimental spectra to absolute spectra (measured in photons per stearadian from the source for radiative transitions at indicated photon energies). Our x-ray spectrographic systems are being applied to the diagnostics of pulsed, high temperature plasma sources in laser fusion and x-ray laser research. 15 refs., 27 figs

Assembly of positioner of automated two-dimensional scan coupled to X-ray fluorescence spectrometry; Montagem de posicionador de varredura bidimensional automatizada acoplado a espectrometria de fluorescência de raios-X

Energy Technology Data Exchange (ETDEWEB)

Silva, Leonardo Santiago Melgaço

2011-07-01

This work describes the design and assembling of a prototype automated positioner two-dimensional scanning coupled to X-ray fluorescence spectrometry. The work aims to achieve a portable and easy to use, device of broad utility in the analysis of samples by X-ray fluorescence area of expertise and research. The two-dimensional scanning of the positioner is by means of two stepper motors controlled by a microcontroller PIC 16F877A, encoder and optical sensors. The user interacts with the XY table through an interface program for the Windows operating system, which communicates with the microcontroller through the serial port. The system of Fluorescence Spectroscopy incorporated into the positioner consists of a system commercially available system from the company AMPTEK, where the primary source of excitation of the sample was a source of {sup 241}Am of 59.5 KeV emissions. Resolution and accuracy of tests were performed in the XY scanning process and reproducibility of the same kit with the fluorescence spectrometry X-ray. Qualitative tests by X-ray fluorescence spectrometry in samples were performed to demonstrate the applicability and versatility of the project. It follows that the prototype illustrates a possible adequately to portable device for X-ray spectrometry of two-dimensional. (author)

The hydroxylation of passive oxide films on X-70 steel by dissolved hydrogen studied by nuclear reaction analysis, Auger electron spectroscopy, X-ray photoelectron spectroscopy and secondary ion mass spectroscopy

International Nuclear Information System (INIS)

Zhang Chunsi; Luo Jingli; Munoz-Paniagua, David; Norton, Peter R.

2006-01-01

Dissolved hydrogen is known to reduce the corrosion resistance of a passive oxide film on iron and its alloys, especially towards pitting corrosion. Electrochemical techniques have been used to show that the passive films are changed by dissolved hydrogen in an alloy substrate, but direct confirmation of the chemical and compositional profiles and changes has been missing. In this paper we report the direct profiling and compositional analysis of the 4 nm passive film on X-70 steel by Auger electron spectroscopy (AES), secondary ion mass spectrometry (SIMS), X-ray photoelectron spectroscopy (XPS) and nuclear reaction analysis (NRA) while hydrogen (deuterium) is charged into the alloy samples from the reverse, unpassivated side. The only route for D to the passive film is therefore by dissolution and diffusion. We show that the original duplex structure of the passive film is converted to a more continuous film containing hydroxyl groups, by reaction with the dissolved hydrogen. This conversion of the oxide ions to hydroxyl groups can lead to more rapid reaction and replacement with (e.g.) Cl - , which is known to enhance pitting. These results are entirely consistent with previous electrochemical studies and provide the first direct confirmation of models on the formation and role of hydroxyl groups derived from these earlier studies

X-ray spectroscopy an introduction

CERN Document Server

Agarwal, Bipin K

1979-01-01

Rontgen's discovery of X-rays in 1895 launched a subject which became central to the development of modern physics. The verification of many of the predic­ tions of quantum theory by X-ray spectroscopy in the early part of the twen­ tieth century stimulated great interest in thi's area, which has subsequently influenced fields as diverse as chemical physics, nuclear physics, and the study of the electronic properties of solids, and led to the development of techniques such as Auger, Raman, and X-ray photoelectron spectroscopy. The improvement of the theoretical understanding of the physics underlying X-ray spectroscopy has been accompanied by advances in experimental techniques, and the subject provides an instructive example of how progress on both these fronts can be mutually beneficial. This book strikes a balance between his­ torical description, which illustrates this symbiosis, and the discussion of new developments. The application of X-ray spectroscopic methods to the in­ vestigation of chemical b...

Determination of the impact of Bi content on the valence band energy of GaAsBi using x-ray photoelectron spectroscopy

Directory of Open Access Journals (Sweden)

K. Collar

2017-07-01

Full Text Available We investigate the change of the valence band energy of GaAs1-xBix (0<x<0.025 as a function of dilute bismuth (Bi concentration, x, using x-ray photoelectron spectroscopy (XPS. The change in the valence band energy per addition of 1 % Bi is determined for strained and unstrained thin films using a linear approximation applicable to the dilute regime. Spectroscopic ellipsometry (SE was used as a complementary technique to determine the change in GaAsBi bandgap resulting from Bi addition. Analysis of SE and XPS data together supports the conclusion that ∼75% of the reduction in the bandgap is in the valence band for a compressively strained, dilute GaAsBi thin film at room temperature.

Boron Doped diamond films as electron donors in photovoltaics: An X-ray absorption and hard X-ray photoemission study

International Nuclear Information System (INIS)

Kapilashrami, M.; Zegkinoglou, I.; Conti, G.; Nemšák, S.; Conlon, C. S.; Fadley, C. S.; Törndahl, T.; Fjällström, V.; Lischner, J.; Louie, Steven G.; Hamers, R. J.; Zhang, L.; Guo, J.-H.; Himpsel, F. J.

2014-01-01

Highly boron-doped diamond films are investigated for their potential as transparent electron donors in solar cells. Specifically, the valence band offset between a diamond film (as electron donor) and Cu(In,Ga)Se 2 (CIGS) as light absorber is determined by a combination of soft X-ray absorption spectroscopy and hard X-ray photoelectron spectroscopy, which is more depth-penetrating than standard soft X-ray photoelectron spectroscopy. In addition, a theoretical analysis of the valence band is performed, based on GW quasiparticle band calculations. The valence band offset is found to be small: VBO = VBM CIGS – VBM diamond  = 0.3 eV ± 0.1 eV at the CIGS/Diamond interface and 0.0 eV ± 0.1 eV from CIGS to bulk diamond. These results provide a promising starting point for optimizing the band offset by choosing absorber materials with a slightly lower valence band maximum.

A strategy for vitrification product assurance and control with X-ray fluorescence spectrometry (PACX)

International Nuclear Information System (INIS)

Resce, J.L.

1995-01-01

A product control strategy is proposed for the vitrification of low-level and/or mixed waste. This strategy is called Product Assurance and Control with X-ray fluorescence spectrometry (PACX). The strategy utilizes sequential wavelength dispersive x-ray fluorescence spectrometry and standardless fundamental parameters calculations to analyze both the melter feed and the glassy products. The melter feed is sampled prior to addition to the melt tank and then melted and cast into samples which should closely resemble the product from the vitrification process itself. The resulting sample disks are then analyzed by x-ray fluorescence spectrometry. All elements with atomic numbers down to sodium can be determined directly and then either boron or lithium can be determined by difference from the mass balance. The XRF intensities are converted into oxide compositions with the use of a novel standardless fundamental parameters program. Previous work has shown that there is an excellent correlation between the XRF results and the results from conventional wet chemical analyses, but the XRF results can be obtained within two to three hours of sampling. If compositional control limits for durability are available, the product acceptability can be determined prior to the batch being introduced into the melter. The durability could also be estimated from a model, if available, which predicts product durability from composition. If the predicted durability is estimated to be too low, the model can then be used to determine additives which will raise the durability of the final product to within acceptable limits. The additives can then be incorporated into the batch prior to addition into the melter. A similar XRF analysis can be carried out on the glass product from the melter which can then be used to predict and thus assure product acceptance

Surface analysis using X-ray photoelectron spectroscopy and X-ray diffraction of UO2 fuel pellets oxidised in air at 2300C and 2700C

International Nuclear Information System (INIS)

Tempest, P.A.; Tyler, J.W.

1987-08-01

Factors which affect the UO 2 → U 3 O 8 transformation have been investigated by sequentially oxidising UO 2 fuel pellets in air at 230 0 C and 270 0 C and monitoring the growth of U 3 O 7 and U 3 O 8 using X-ray photoelectron spectroscopy, X-ray diffraction and scanning electron microscopy. Initially oxidation proceeded at a linear rate by the inward diffusion of oxygen to form a complete layer of sub-stoichiometric U 3 O 7 . This phase was tetragonal with a c/a ratio of 1.015, significantly less than the value of 1.03 measured on UO 2 powder when oxidised under identical conditions. This difference and the preferred orientation exhibited by surface grains were caused by growth stresses induced in the pellet surface. Both intergranular and transgranular cracking occurred and became nucleation sites for the growth of U 3 O 8 . The linear oxidation period associated with U 3 O 7 growth was much shorter at 270 0 C than 230 0 C and U 3 O 8 nucleated earlier. Spallation and the production of particulate were only observed during the formation of U 3 O 8 when a 30% increase in volume arose from the U 3 O 7 → U 3 O 8 phase change. (author)

Measurement of the valence band-offset in a PbSe/ZnO heterojunction by x-ray photoelectron spectroscopy

Energy Technology Data Exchange (ETDEWEB)

Li Lin; Qiu Jijun; Weng Binbin; Yuan Zijian; Shi Zhisheng [School of Electrical and Computer Engineering, University of Oklahoma, Norman, Oklahoma 73019 (United States); Li Xiaomin; Gan Xiaoyan [State Key Laboratory of High Performance Ceramics and Superfine Microstructures, Shanghai Institute of Ceramics, Chinese Academy of Sciences, Shanghai 200050 (China); Sellers, Ian R. [Deparment of Physics, University of Oklahoma, Norman, Oklahoma 73019 (United States)

2012-12-24

A heterojunction of PbSe/ZnO has been grown by molecular beam epitaxy. X-ray photoelectron spectroscopy was used to directly measure the valence-band offset (VBO) of the heterojunction. The VBO, {Delta}E{sub V}, was determined as 2.51 {+-} 0.05 eV using the Pb 4p{sup 3/2} and Zn 2p{sup 3/2} core levels as a reference. The conduction-band offset, {Delta}E{sub C}, was, therefore, determined to be 0.59 {+-} 0.05 eV based on the above {Delta}E{sub V} value. This analysis indicates that the PbSe/ZnO heterojunction forms a type I (Straddling Gap) heterostructure.

A double cell for X-ray absorption spectrometry of atomic Zn

CERN Document Server

Mihelic, A; Arcon, I; Padeznik-Gomilsek, J; Borowski, M

2002-01-01

A high-temperature cell with a double wall design has been constructed for X-ray absorption spectrometry of metal vapors. The inner cell, assembled from a corundum tube and thin plates without welding or reshaping, serves as a container of the vapor sample. It is not vacuum tight: instead, the outer tube provides inert atmosphere. Several spectra of K-edge atomic absorption of Zn were obtained in the stationary working regime below the Zn boiling point. The K-edge profile shows an extremely strong resonance and, above the continuum threshold, coexcitations of the outer electrons.

Segmented-spectrum detection mechanism for medical x-ray in CdTe

Science.gov (United States)

Shi, Zaifeng; Meng, Qingzhen; Cao, Qingjie; Yao, Suying

2016-01-01

This paper presents a segmented X-ray spectrum detection method based on a layered X-ray detector in Cadmium Telluride (CdTe) substrate. We describe the three-dimensional structure of proposed detector pixel and investigate the matched spectrum-resolving method. Polychromatic X-ray beam enter the CdTe substrate edge on and will be absorbed completely in different thickness varying with photon energy. Discrete potential wells are formed under external controlling voltage to collect the photo-electrons generated in different layers, and segmented X-ray spectrum can be deduced from the quantity of photo-electrons. In this work, we verify the feasibility of the segmented-spectrum detection mechanism by simulating the absorption of monochromatic X-ray in a CdTe substrate. Experiments in simulation show that the number of photo-electrons grow exponentially with the increase of incident thickness, and photons with different energy will be absorbed in various thickness. The charges generated in different layers are collected into adjacent potential wells, and collection efficiency is estimated to be about 87% for different incident intensity under the 40000V/cm electric field. Errors caused by charge sharing between neighboring layers are also analyzed, and it can be considered negligible by setting appropriate size of electrodes.

Synthesis, structural, X-ray photoelectron spectroscopy (XPS) studies and IR induced anisotropy of Tl{sub 4}HgI{sub 6} single crystals

Energy Technology Data Exchange (ETDEWEB)

Parasyuk, O.V. [Department of Inorganic and Physical Chemistry, Lesya Ukrainka Eastern European National University, Voli Ave. 13, Lutsk, 43025 (Ukraine); Khyzhun, O.Y. [Frantsevych Institute for Problems of Materials Science, National Academy of Sciences of Ukraine, 3 Krzhyzhanivsky St., 03142, Kyiv (Ukraine); Piasecki, M. [Institute of Physics, J. Dlugosz University Częstochowa, Armii Krajowej 13/15, Częstochowa (Poland); Kityk, I.V., E-mail: iwank74@gmail.com [Electrical Engineering Department, Czestochowa University Technology, Armii Krajowej 17, PL-42-217, Czestochowa (Poland); Lakshminarayana, G. [Wireless and Photonic Networks Research Centre, Faculty of Engineering, Universiti Putra Malaysia, 43400, Serdang, Selangor (Malaysia); Luzhnyi, I. [Frantsevych Institute for Problems of Materials Science, National Academy of Sciences of Ukraine, 3 Krzhyzhanivsky St., 03142, Kyiv (Ukraine); Fochuk, P.M. [Yuriy Fed’kovych Chernivtsi National University, 2 Kotziubynskoho Str., 58012, Chernivtsi (Ukraine); Fedorchuk, A.O. [Department of Inorganic and Organic Chemistry, Lviv National University of Veterinary Medicine and Biotechnologies, Pekarska Street 50, 79010, Lviv (Ukraine); Levkovets, S.I.; Yurchenko, O.M.; Piskach, L.V. [Department of Inorganic and Physical Chemistry, Lesya Ukrainka Eastern European National University, Voli Ave. 13, Lutsk, 43025 (Ukraine)

2017-02-01

In the present work, we report on the synthesis and structural properties including X-ray protoelectron spectroscopy (XPS) analysis of Tl{sub 4}HgI{sub 6} crystals that were grown by Bridgman-Stockbarger method up to 80 mm in length and 18 mm in diameter. The existence of the ternary compound Tl{sub 4}HgI{sub 6} that melts incongruently at 641 K was confirmed. Phase equilibria and structural properties for the TlI–HgI{sub 2} system were investigated by differential thermal analysis (DTA) and X-ray diffraction (XRD) methods. X-ray photoelectron spectra were measured for both pristine and Ar{sup +} ion-bombarded Tl{sub 4}HgI{sub 6} single crystal surfaces. The data reveal that the Tl{sub 4}HgI{sub 6} single crystal is sensitive with respect to Ar{sup +} ion-bombardment as 3.0 keV Ar{sup +} irradiation over 5 min at an ion current density 14 μA/cm{sup 2} induces changes to the elemental stoichiometry of the Tl{sub 4}HgI{sub 6} surface, leading to a decrease of the mercury content in the topmost surface layers. X-ray photoelectron spectroscopy (XPS) measurements indicate very low hygroscopic nature of the Tl{sub 4}HgI{sub 6} single crystal surface. The IR coherent bicolor laser treatment at wavelengths 10.6/5.3 μm has shown an occurrence of anisotropy at wavelengths 1540 nm of Er:glass laser. This may open the applications of Tl{sub 4}HgI{sub 6} as a material for IR laser triggering. - Highlights: • Phase diagram of the HgI{sub 2}–TlI system was built. • Tl{sub 4}HgI{sub 6} single crystals were grown by Bridgman Stockbarger method. • XRD, XPS analysis was done. • Ir induced anisotropy was established. • The compounds may be proposed as Ir laser operated polarizers.

A new generation of x-ray spectrometry UHV instruments at the SR facilities BESSY II, ELETTRA and SOLEIL

Energy Technology Data Exchange (ETDEWEB)

Lubeck, J., E-mail: janin.lubeck@ptb.de; Fliegauf, R.; Holfelder, I.; Hönicke, P.; Müller, M.; Pollakowski, B.; Ulm, G.; Weser, J.; Beckhoff, B. [Physikalisch-Technische Bundesanstalt (PTB), Abbestr. 2-12, 10587 Berlin (Germany); Bogovac, M.; Kaiser, R. B.; Karydas, A. G.; Leani, J. J.; Migliori, A.; Sghaier, H. [Nuclear Science and Instrumentation Laboratory, IAEA Laboratories, A-2444, Seibersdorf (Austria); Boyer, B.; Lépy, M. C.; Ménesguen, Y. [CEA, LIST, Laboratoire National Henri Becquerel, Bât. 602 PC 111, CEA-Saclay 91191 Gif-sur-Yvette c. (France); Detlefs, B. [CEA-LETI, Minatec Campus, 17 rue des Martyrs, 38054 Grenoble (France); Eichert, D. [Elettra - Sincrotrone Trieste (EST) S.C.p.A., 34149 Basovizza, Trieste (Italy); and others

2016-07-27

A novel type of ultra-high vacuum instrument for X-ray reflectometry and spectrometry-related techniques for nanoanalytics by means of synchrotron radiation (SR) has been constructed and commissioned at BESSY II. This versa-tile instrument was developed by the PTB, Germany’s national metrology institute, and includes a 9-axis manipulator that allows for an independent alignment of the samples with respect to all degrees of freedom. In addition, it integrates a rotational and translational movement of several photodiodes as well as a translational movement of a beam-geometry-defining aperture system. Thus, the new instrument enables various analytical techniques based on energy dispersive X-ray detectors such as reference-free X-Ray Fluorescence (XRF) analysis, total-reflection XRF, grazing-incidence XRF, in addition to optional X-Ray Reflectometry (XRR) measurements or polarization-dependent X-ray absorption fine structure analyses (XAFS). Samples having a size of up to (100 × 100) mm{sup 2}; can be analyzed with respect to their mass deposition, elemental, spatial or species composition. Surface contamination, nanolayer composition and thickness, depth pro-file of matrix elements or implants, nanoparticles or buried interfaces as well as molecular orientation of bonds can be accessed. Three technology transfer projects of adapted instruments have enhanced X-Ray Spectrometry (XRS) research activities within Europe at the synchrotron radiation facilities ELETTRA (IAEA) and SOLEIL (CEA/LNE-LNHB) as well as at the X-ray innovation laboratory BLiX (TU Berlin) where different laboratory sources are used. Here, smaller chamber requirements led PTB in cooperation with TU Berlin to develop a modified instrument equipped with a 7-axis manipulator: reduced freedom in the choice of experimental geometry modifications (absence of out-of-SR-plane and reference-free XRS options) has been compensated by encoder-enhanced angular accuracy for GIXRF and XRR.

X-ray microprobe for the microcharacterization of materials

International Nuclear Information System (INIS)

Sparks, C.J.; Ice, G.E.

1988-01-01

The unique properties of x rays offer many advantages over those of electrons and other charged particles for the microcharacterization of materials. X rays are more efficient in exciting characteristic x-ray fluorescence and produce higher fluorescent signal-to-background ratios than obtained with electrons. Such x-ray microprobes will also produce unprecedentedly low levels of detection in diffraction, EXAFS, Auger, and photoelectron spectroscopies for structural and chemical characterization and elemental identification. These major improvements in microcharacterization capabilities will have wide-ranging ramifications not only in materials science but also in physics, chemistry, geochemistry, biology, and medicine. 24 refs., 6 figs., 2 tabs

Application of delayed X-ray spectrometry to the analysis of some rare earth elements

International Nuclear Information System (INIS)

Pillay, A.E.; Mboweni, R.C.M.

1991-01-01

The capabilities of delayed x-ray spectrometry preceded by isotope-source thermal neutron activation for the specific determination of some rare earth elements (Sm, Eu, Dy, Ho) in small powdered samples was evaluated. The feasibility study relied heavily on the low-energy sensitivity of the detector used. Detection of the delayed x-rays was achieved with a 100-mm 2 Ge detector with the ability to produce optimum photopeak-to-noise ratios. The rare earth elements were chosen on the basis of their inherent favourable nuclear properties for producing a practicable x-ray yield and on the demand for their analysis. Analytical results are presented over a range of concentrations for the elements of interest and the potential of the technique for application to their general routine analysis is discussed. Interferences from the sample matrix can be suppressed to an extent that makes the method almost independent of the matrix. This and other features make the technique a strong rival to conventional activation analysis. (author)

Magnetometry of buried layers—Linear magnetic dichroism and spin detection in angular resolved hard X-ray photoelectron spectroscopy

International Nuclear Information System (INIS)

Gloskovskii, Andrei; Stryganyuk, Gregory; Fecher, Gerhard H.; Felser, Claudia; Thiess, Sebastian; Schulz-Ritter, Heiko; Drube, Wolfgang; Berner, Götz; Sing, Michael; Claessen, Ralph; Yamamoto, Masafumi

2012-01-01

Highlights: ► Newly commissioned HAXPES instrument at P09 beamline of the PETRA III ring at DESY. ► We report HAXPES studies on buried magnetic nanolayers in a multi-layer sample. ► Linear magnetic dichroism of photoelectrons from buried CoFe–Ir 78 Mn 22 layers. ► Spin-resolved HAXPES measurements on buried magnetic multilayers using Mott detector. - Abstract: The electronic properties of buried magnetic nano-layers were studied using the linear magnetic dichroism in the angular distribution of photoemitted Fe, Co, and Mn 2p electrons from a CoFe–Ir 78 Mn 22 multi-layered sample. The buried layers were probed using hard X-ray photoelectron spectroscopy, HAXPES, at the undulator beamline P09 of the 3rd generation storage ring PETRA III. The results demonstrate that this magnetometry technique can be used as a sensitive element specific probe for magnetic properties suitable for application to buried ferromagnetic and antiferromagnetic magnetic materials and multilayered spintronics devices. Using the same instrument, spin-resolved Fe 2p HAXPES spectra were obtained from the buried layer with good signal quality.

ESCADT: a FORTRAN code for computing the positions and areas of x-ray photoelectron spectral peaks

International Nuclear Information System (INIS)

Cox, L.E.

1979-09-01

Program ESCADT uses least-squares-derived convoluting numbers to smooth and differentiate x-ray photoelectron spectra. Peak maxima are located by finding zero crossings of the first derivative and refined using a cubic polynomial fitting procedure. Background points are located using the product of the absolute value of the first derivative and the smoothed ordinate value. Peak areas, using both linear and scattered electron backgrounds, are computed. Spectra are corrected for changes in instrument sensitivity and energy calibration with gold-standard data retrieved from a disk file. Five determinations of the gold 4f peak positions yielded standard deviations of 0.011 and 0.031 eV for the 4f/sub 7/2/ and 4f/sub 5/2/ peaks, respectively. The relative standard deviation for the computed areas was 0.85%

Accurate quasiparticle calculation of x-ray photoelectron spectra of solids.

Science.gov (United States)

Aoki, Tsubasa; Ohno, Kaoru

2018-05-31

It has been highly desired to provide an accurate and reliable method to calculate core electron binding energies (CEBEs) of crystals and to understand the final state screening effect on a core hole in high resolution x-ray photoelectron spectroscopy (XPS), because the ΔSCF method cannot be simply used for bulk systems. We propose to use the quasiparticle calculation based on many-body perturbation theory for this problem. In this study, CEBEs of band-gapped crystals, silicon, diamond, β-SiC, BN, and AlP, are investigated by means of the GW approximation (GWA) using the full ω integration and compared with the preexisting XPS data. The screening effect on a deep core hole is also investigated in detail by evaluating the relaxation energy (RE) from the core and valence contributions separately. Calculated results show that not only the valence electrons but also the core electrons have an important contribution to the RE, and the GWA have a tendency to underestimate CEBEs due to the excess RE. This underestimation can be improved by introducing the self-screening correction to the GWA. The resulting C1s, B1s, N1s, Si2p, and Al2p CEBEs are in excellent agreement with the experiments within 1 eV absolute error range. The present self-screening corrected GW approach has the capability to achieve the highly accurate prediction of CEBEs without any empirical parameter for band-gapped crystals, and provide a more reliable theoretical approach than the conventional ΔSCF-DFT method.

CHARACTERIZING SURFACE LAYERS IN NITINOL USING X-RAY PHOTOELECTRON SPECTROSCOPY

Energy Technology Data Exchange (ETDEWEB)

Christopfel, R.; Mehta, A.

2008-01-01

Nitinol is a shape memory alloy whose properties allow for large reversible deformations and a return to its original geometry. This nickel-titanium (NiTi) alloy has become a material used widely in the biomedical fi eld as a stent to open up collapsed arteries. Both ambient and biological conditions cause surface oxidation in these devices which in turn change its biocompatibility. The thickness of oxidized layers can cause fractures in the material if too large and can allow for penetration if too thin. Depending on the type and abundance of the chemical species on or near the surface, highly toxic metal ions can leak into the body causing cell damage or even cell death. Thus, biocompatibility of such devices is crucial. By using highly surface sensitive x-ray photoelectron spectroscopy to probe the surface of these structures, it is possible to decipher both layer composition and layer thickness. Two samples, both of which were mechanically polished, were investigated. Of the two samples, one was then exposed to a phosphate buffered saline (PBS) solution to mimic the chemical properties of blood, while the other remained unexposed. Although both samples were found to have oxide layers of appropriate thickness (on the order of a few nm), it was found that the sample exposed to the saline solution had a slightly thicker oxide layer and more signifi cantly, a phosphate layer very near the surface suggesting toxic metal components are well contained within the sample. These are considerable indications of a biocompatible device.

Accurate quasiparticle calculation of x-ray photoelectron spectra of solids

Science.gov (United States)

Aoki, Tsubasa; Ohno, Kaoru

2018-05-01

It has been highly desired to provide an accurate and reliable method to calculate core electron binding energies (CEBEs) of crystals and to understand the final state screening effect on a core hole in high resolution x-ray photoelectron spectroscopy (XPS), because the ΔSCF method cannot be simply used for bulk systems. We propose to use the quasiparticle calculation based on many-body perturbation theory for this problem. In this study, CEBEs of band-gapped crystals, silicon, diamond, β-SiC, BN, and AlP, are investigated by means of the GW approximation (GWA) using the full ω integration and compared with the preexisting XPS data. The screening effect on a deep core hole is also investigated in detail by evaluating the relaxation energy (RE) from the core and valence contributions separately. Calculated results show that not only the valence electrons but also the core electrons have an important contribution to the RE, and the GWA have a tendency to underestimate CEBEs due to the excess RE. This underestimation can be improved by introducing the self-screening correction to the GWA. The resulting C1s, B1s, N1s, Si2p, and Al2p CEBEs are in excellent agreement with the experiments within 1 eV absolute error range. The present self-screening corrected GW approach has the capability to achieve the highly accurate prediction of CEBEs without any empirical parameter for band-gapped crystals, and provide a more reliable theoretical approach than the conventional ΔSCF-DFT method.

X-ray photoelectron spectroscopy studies of nitridation on 4H-SiC (0001) surface by direct nitrogen atomic source

International Nuclear Information System (INIS)

Chai, J. W.; Pan, J. S.; Zhang, Z.; Wang, S. J.; Chen, Q.; Huan, C. H. A.

2008-01-01

A Si 3 N 4 passivation layer has been successfully grown on the 4H-SiC (0001) surface by direct atomic source nitridation at various substrate temperatures. In situ x-ray photoelectron spectroscopy measurements show that higher substrate temperature leads to higher nitridation rate and good crystallinity of the passivation layer. A thin oxynitride layer on the top of the Si 3 N 4 was observed due to the residual O in the vacuum system, but was decomposed during annealing. In the meantime, excess C was found to be effectively removed by the reactive atomic N source

Assessment of coal and ash environmental impact with the use of gamma- and X-ray spectrometry

International Nuclear Information System (INIS)

Kierzek, J.; Malozewska-Bucko, B.; Bukowski, P.; Parus, J.L.; Ciurapisnki, A.; Zaras, S.; Kunach, B.; Wiland, K.

1999-01-01

Gamma-ray spectrometry (GS), energy dispersive X-ray fluorescence (EDXRF) analysis methods and wavelength dispersive X-ray fluorescence (WDXRF) were applied for the studies of some coal components, e.g., sulphur, light and heavy metal element concentrations and naturally occurring radioactive isotope contents. Hundred fifty coal samples originating mostly from eight different coal mines from Upper Silesian Coal Basin and 150 samples of ash obtained from these coal samples in laboratory by total combustion at final temperature of 820 deg C, were analyzed. Such comparative analyses can be helpful in selection of most suitable kind of coal for burning in electrical power and heat plants to minimize the environmental pollution. (author)

Determination of U, Th and K in bricks by gamma -ray spectrometry, X-ray fluorescence analysis and neutron activation analysis

Czech Academy of Sciences Publication Activity Database

Bártová, H.; Kučera, Jan; Musílek, L.; Trojek, T.; Gregorová, E.

2017-01-01

Roč. 140, NOV (2017), s. 161-166 ISSN 0969-806X R&D Projects: GA MŠk LM2015056 Institutional support: RVO:61389005 Keywords : Gamma-ray spectrometry * neutron activation analysis * environmental dosimetry Subject RIV: CB - Analytical Chemistry , Separation OBOR OECD: Analytical chemistry Impact factor: 1.315, year: 2016

X-ray microscopy: An emerging technique for semiconductor microstructure characterization

International Nuclear Information System (INIS)

Padmore, H.A.

1998-05-01

The advent of third generation synchrotron radiation x-ray sources, such as the Advanced Light Source (ALS) at Berkeley have enabled the practical realization of a wide range of new techniques in which mature chemical or structural probes such as x-ray photoelectron spectroscopy (XPS) and x-ray diffraction are used in conjunction with microfocused x-ray beams. In this paper the characteristics of some of these new microscopes are described, particularly in reference to their applicability to the characterization of semiconductor microstructures

LabVIEW interface with Tango control system for a multi-technique X-ray spectrometry IAEA beamline end-station at Elettra Sincrotrone Trieste

Energy Technology Data Exchange (ETDEWEB)

Wrobel, P.M. [Physics Section, Nuclear Science and Instrumentation Laboratory (NSIL), IAEA Laboratories, A-2444 Seibersdorf (Austria); AGH University of Science and Technology, Faculty of Physics and Applied Computer Science, al. A. Mickiewicza 30, 30-059 Krakow (Poland); Bogovac, M. [Physics Section, Nuclear Science and Instrumentation Laboratory (NSIL), IAEA Laboratories, A-2444 Seibersdorf (Austria); Sghaier, H. [Physics Section, Nuclear Science and Instrumentation Laboratory (NSIL), IAEA Laboratories, A-2444 Seibersdorf (Austria); Institut Superieur d’Informatique et de Mathematiques de Monastir (ISIMM), Departement de technologie, 5000 Monastir (Tunisia); Leani, J.J. [Physics Section, Nuclear Science and Instrumentation Laboratory (NSIL), IAEA Laboratories, A-2444 Seibersdorf (Austria); IFEG – CONICET, Facultad de Matematica Astronomia y Fisica, Universidad Nacional de Cordoba, 5000 Cordoba (Argentina); Migliori, A.; Padilla-Alvarez, R. [Physics Section, Nuclear Science and Instrumentation Laboratory (NSIL), IAEA Laboratories, A-2444 Seibersdorf (Austria); Czyzycki, M. [Physics Section, Nuclear Science and Instrumentation Laboratory (NSIL), IAEA Laboratories, A-2444 Seibersdorf (Austria); AGH University of Science and Technology, Faculty of Physics and Applied Computer Science, al. A. Mickiewicza 30, 30-059 Krakow (Poland); Osan, J. [Physics Section, Nuclear Science and Instrumentation Laboratory (NSIL), IAEA Laboratories, A-2444 Seibersdorf (Austria); Environmental Physics Department, Hungarian Academy of Sciences Centre for Energy Research, Konkoly-Thege M. út 29-33., H-1121 Budapest (Hungary); Kaiser, R.B. [Physics Section, Nuclear Science and Instrumentation Laboratory (NSIL), IAEA Laboratories, A-2444 Seibersdorf (Austria); and others

2016-10-11

A new synchrotron beamline end-station for multipurpose X-ray spectrometry applications has been recently commissioned and it is currently accessible by end-users at the XRF beamline of Elettra Sincrotrone Trieste. The end-station consists of an ultra-high vacuum chamber that includes as main instrument a seven-axis motorized manipulator for sample and detectors positioning, different kinds of X-ray detectors and optical cameras. The beamline end-station allows performing measurements in different X-ray spectrometry techniques such as Microscopic X-Ray Fluorescence analysis (µXRF), Total Reflection X-Ray Fluorescence analysis (TXRF), Grazing Incidence/Exit X-Ray Fluorescence analysis (GI-XRF/GE-XRF), X-Ray Reflectometry (XRR), and X-Ray Absorption Spectroscopy (XAS). A LabVIEW Graphical User Interface (GUI) bound with Tango control system consisted of many custom made software modules is utilized as a user-friendly tool for control of the entire end-station hardware components. The present work describes this advanced Tango and LabVIEW software platform that utilizes in an optimal synergistic manner the merits and functionality of these well-established programming and equipment control tools. - Highlights: • A new methodology for control of a synchrotron beamline end-station is shown. • The new control system comprises a novel binding of Tango control system with LabVIEW interface. • The reliability of the control system is demonstrated by examples of analytical applications.

On the nature of citrate-derived surface species on Ag nanoparticles: Insights from X-ray photoelectron spectroscopy

Science.gov (United States)

Mikhlin, Yuri L.; Vorobyev, Sergey A.; Saikova, Svetlana V.; Vishnyakova, Elena A.; Romanchenko, Alexander S.; Zharkov, Sergey M.; Larichev, Yurii V.

2018-01-01

Citrate is an important stabilizing, reducing, and complexing reagent in the wet chemical synthesis of nanoparticles of silver and other metals, however, the exact nature of adsorbates, and its mechanism of action are still uncertain. Here, we applied X-ray photoelectron spectroscopy, soft X-ray absorption near-edge spectroscopy, and other techniques in order to determine the surface composition and to specify the citrate-related species at Ag nanoparticles immobilized from the dense hydrosol prepared using room-temperature reduction of aqueous Ag+ ions with ferrous ions and citrate as stabilizer (Carey Lea method). It was found that, contrary to the common view, the species adsorbed on the Ag nanoparticles are, in large part, products of citrate decomposition comprising an alcohol group and one or two carboxylate bound to the surface Ag, and minor unbound carboxylate group; these may also be mixtures of citrate with lower molecular weight anions. No ketone groups were specified, and very minor surface Ag(I) and Fe (mainly, ferric oxyhydroxides) species were detected. Moreover, the adsorbates were different at AgNPs having various size and shape. The relation between the capping and the particle growth, colloidal stability of the high-concentration sol and properties of AgNPs is briefly considered.

Combined analysis of 1,3-benzodioxoles by crystalline sponge X-ray crystallography and laser desorption ionization mass spectrometry.

Science.gov (United States)

Hayashi, Yukako; Ohara, Kazuaki; Taki, Rika; Saeki, Tomomi; Yamaguchi, Kentaro

2018-03-12

The crystalline sponge (CS) method, which employs single-crystal X-ray diffraction to determine the structure of an analyte present as a liquid or an oil and having a low melting point, was used in combination with laser desorption ionization mass spectrometry (LDI-MS). 1,3-Benzodioxole derivatives were encapsulated in CS and their structures were determined by combining X-ray crystallography and MS. After the X-ray analysis, the CS was subjected to imaging mass spectrometry (IMS) with an LDI spiral-time-of-flight mass spectrometer (TOF-MS). The ion detection area matched the microscopic image of the encapsulated CS. In addition, the accumulated 1D mass spectra showed that fragmentation of the guest molecule (hereafter, guest) can be easily visualized without any interference from the fragment ions of CS except for two strong ion peaks derived from the tridentate ligand TPT (2,4,6-tris(4-pyridyl)-1,3,5-triazine) of the CS and its fragment. X-ray analysis clearly showed the presence of the guest as well as the π-π, CH-halogen, and CH-O interactions between the guest and the CS framework. However, some guests remained randomly diffused in the nanopores of CS. In addition, the detection limit was less than sub-pmol order based on the weight and density of CS determined by X-ray analysis. Spectroscopic data, such as UV-vis and NMR, also supported the encapsulation of the guest through the interaction between the guest and CS components. The results denote that the CS-LDI-MS method, which combines CS, X-ray analysis and LDI-MS, is effective for structure determination.

Quantitative in-depth state analysis by means of x-ray photoelectron spectroscopy and its application to surface Layer of SiC coatings

International Nuclear Information System (INIS)

Yabe, Katsumasa; Yamashina, Toshiro.

1980-01-01

An attempt of quantitative state analysis was made on the surface and the depth profile of inorganic compounds by X-ray photoelectron spectroscopy (XPS) which was combined by the sputter-etching with argon ions. A masking attachment was designed for an area of sample which is exposed to the non-uniform portion of the ion beam. Uniform sputter-etching could be attained, with the advantages on XPS observation of low background level and less impurity spectra from other origins than the sample. The photoelectron yields were examined for the quantitative analysis by XPS. The method established here was applied to analyze the surface and in-depth composition of SiC coatings onto carbon and molybdenum which are promising candidate materials as the first wall in a controlled thermonuclear reactor. (author)

X-ray photoelectron spectroscopy of high-temperature superconductor clean surfaces and interfaces

International Nuclear Information System (INIS)

Hill, D.M.

1989-01-01

X-ray photoelectron spectroscopy was used to determine the characteristic spectra for the high temperature superconductors La 1.85 Sr 0.15 CuO 4 , YBa 2 Cu 3 O 7-x , and Bi 2 Sr 2-x Ca 1+x Cu 2 O 8+y and their impurity phases. The oxidation state of Cu in all of these materials was predominantly Cu 2+ . The O 1s emission for clean surfaces was a single broad peak near 529 eV derived from emission from inequivalent O sites in the superconductors. The valence bands were a -6 eV wide manifold of Cu 3d-O 2p hybrid bands in the ∼ 1-7 eV binding energy range, with very low emission at E F arising from antibonding Cu 3d-O 2p orbitals. Emission from grain boundary and other impurity phases appeared at 531 eV for the O 1s core level, and in general ∼ 1-2 eV higher energy than the superconductor peak for other core levels except for Cu 2p. Impurity phases appeared in the valence bands as a shoulder at ∼ 5 eV. The amount of impurities detected was shown to be dependent on the fracture properties of the superconductors. All of the materials were shown to be stable under vacuum. The products and spatial extent of chemical reactions with Ag, Al, Al oxide, Au, Bi, Bi oxide, CaF 2 , Cu, Fe, Si, and Si oxide overlayers on these materials also were examined. Au, CaF 2 , and metal oxides deposited by activated oxidation during evaporation were non-reactive and non-disruptive of the superconductor surfaces. Ag overlayers were unique in that they disrupted the superconductor during deposition, but exhibited no evidence of any chemical reactions. Overlayers with an affinity for oxygen withdrew O from the superconductor. The O loss occurred preferentially from Cu atoms in the superconductor and disrupted the planar bonding structure

Recent trends in total reflection X-ray fluorescence spectrometry for biological applications

International Nuclear Information System (INIS)

Szoboszlai, Norbert; Polgari, Zsofia; Mihucz, Victor G.; Zaray, Gyula

2009-01-01

This review is focused on the application of total reflection X-ray fluorescence (TXRF) spectrometry in the field of biological research. In the last decade, most papers were published by authors who applied laboratory-scale TXRF equipments. The application of synchrotron radiation as excitation source (SR-TXRF) shows a slowly increasing tendency. In the cited papers the micro-, trace and multielement capability of these TXRF techniques was demonstrated in the clinical and medical laboratory practice, as well as in various plant physiological studies. For speciation of elements in biological matrices, the TXRF was used as element specific detector following an off-line separation step (e.g., thin layer chromatography, high performance liquid chromatography), however, these off-line methods are not competitive with the on-line coupled HPLC-inductively coupled plasma mass spectrometry

Temperature effect on X-ray photoelectron spectra of 3d transition metal ions

International Nuclear Information System (INIS)

Kochur, A.G.; Kozakov, A.T.; Yavna, V.A.; Daniel, Ph.

2014-01-01

Highlights: • 2p XPS of 3d metal ions are calculated in an isolated ion approximation. • 2p XPS of Ti, V, Cr, Mn, Fe ions are temperature dependent even at room temperature. • Temperature effect on 3p XPS is slight. • No temperature effect on 3s XPS is discovered. - Abstract: Temperature effect on 2p- 3s- and 3p X-ray photoelectron spectra (XPS) of various ions of Ti, V, Cr, Mn and Fe is studied theoretically within an isolated ion approximation. It is shown that the 2p XPS of those ions are temperature dependent even at room temperature due to a very slight energy splitting between the ground-state-term total-momentum J-components which can be thermally populated. Most significant temperature effect is expected in the 2p-spectra of Ti 2+ (3d 2 ), V 2+ (3d 3 ), Cr 2+ (3d 4 ), Mn 3+ (3d 4 ), and Mn 3+ (3d 4 ) ions. The temperature effect on 3p XPS is slight. No temperature effect on 3s XPS is expected

Band alignment of HfO{sub 2}/AlN heterojunction investigated by X-ray photoelectron spectroscopy

Energy Technology Data Exchange (ETDEWEB)

Ye, Gang [School of Electrical and Electronic Engineering, Nanyang Technological University, Singapore 639798 (Singapore); Wang, Hong, E-mail: ewanghong@ntu.edu.sg [School of Electrical and Electronic Engineering, Nanyang Technological University, Singapore 639798 (Singapore); CNRS-International-NTU-THALES Research Alliances/UMI 3288, 50 Nanyang Drive, Singapore 637553 (Singapore); Ji, Rong [Data Storage Institute, Agency for Science Technology and Research (A-STAR), Singapore 117608 (Singapore)

2016-04-18

The band alignment between AlN and Atomic-Layer-Deposited (ALD) HfO{sub 2} was determined by X-ray photoelectron spectroscopy (XPS). The shift of Al 2p core-levels to lower binding energies with the decrease of take-off angles θ indicated upward band bending occurred at the AlN surface. Based on the angle-resolved XPS measurements combined with numerical calculations, valence band discontinuity ΔE{sub V} of 0.4 ± 0.2 eV at HfO{sub 2}/AlN interface was determined by taking AlN surface band bending into account. By taking the band gap of HfO{sub 2} and AlN as 5.8 eV and 6.2 eV, respectively, a type-II band line-up was found between HfO{sub 2} and AlN.

Surface chemical composition of human maxillary first premolar as assessed by X-ray photoelectron spectroscopy (XPS)

Science.gov (United States)

Lou, Leo; Nelson, Alan E.; Heo, Giseon; Major, Paul W.

2008-08-01

The surface chemical composition of dental enamel has been postulated as a contributing factor in the variation of bond strength of brackets bonded to teeth, and hence, the probability of bracket failure during orthodontic treatment. This study systematically investigated the chemical composition of 98 bonding surfaces of human maxillary premolars using X-ray photoelectron spectroscopy (XPS) to ascertain compositional differences between right and left first premolars. The major elements detected in all samples were calcium, phosphorus, oxygen, nitrogen and carbon. Surface compositions were highly variable between samples and several elements were found to be highly correlated. No statistical significant difference in the chemical composition of the maxillary right and left first premolars was found ( p > 0.05). Knowledge of the chemical composition of enamel surfaces will facilitate future studies that relate this information to the variations in dental enamel bond strength.

Surface chemical composition of human maxillary first premolar as assessed by X-ray photoelectron spectroscopy (XPS)

Energy Technology Data Exchange (ETDEWEB)

Lou, Leo [Orthodontic Graduate Program, Faculty of Medicine and Dentistry, University of Alberta (Canada); Nelson, Alan E. [Department of Chemical and Materials Engineering, University of Alberta (Canada)], E-mail: aenelson@dow.com; Heo, Giseon [Department of Statistics, Department of Dentistry, University of Alberta (Canada); Major, Paul W. [Orthodontic Graduate Program, Faculty of Medicine and Dentistry, University of Alberta (Canada)

2008-08-30

The surface chemical composition of dental enamel has been postulated as a contributing factor in the variation of bond strength of brackets bonded to teeth, and hence, the probability of bracket failure during orthodontic treatment. This study systematically investigated the chemical composition of 98 bonding surfaces of human maxillary premolars using X-ray photoelectron spectroscopy (XPS) to ascertain compositional differences between right and left first premolars. The major elements detected in all samples were calcium, phosphorus, oxygen, nitrogen and carbon. Surface compositions were highly variable between samples and several elements were found to be highly correlated. No statistical significant difference in the chemical composition of the maxillary right and left first premolars was found (p > 0.05). Knowledge of the chemical composition of enamel surfaces will facilitate future studies that relate this information to the variations in dental enamel bond strength.

Surface chemical composition of human maxillary first premolar as assessed by X-ray photoelectron spectroscopy (XPS)

International Nuclear Information System (INIS)

Lou, Leo; Nelson, Alan E.; Heo, Giseon; Major, Paul W.

2008-01-01

The surface chemical composition of dental enamel has been postulated as a contributing factor in the variation of bond strength of brackets bonded to teeth, and hence, the probability of bracket failure during orthodontic treatment. This study systematically investigated the chemical composition of 98 bonding surfaces of human maxillary premolars using X-ray photoelectron spectroscopy (XPS) to ascertain compositional differences between right and left first premolars. The major elements detected in all samples were calcium, phosphorus, oxygen, nitrogen and carbon. Surface compositions were highly variable between samples and several elements were found to be highly correlated. No statistical significant difference in the chemical composition of the maxillary right and left first premolars was found (p > 0.05). Knowledge of the chemical composition of enamel surfaces will facilitate future studies that relate this information to the variations in dental enamel bond strength

Single particle transfer for quantitative analysis with total-reflection X-ray fluorescence spectrometry

International Nuclear Information System (INIS)

Esaka, Fumitaka; Esaka, Konomi T.; Magara, Masaaki; Sakurai, Satoshi; Usuda, Shigekazu; Watanabe, Kazuo

2006-01-01

The technique of single particle transfer was applied to quantitative analysis with total-reflection X-ray fluorescence (TXRF) spectrometry. The technique was evaluated by performing quantitative analysis of individual Cu particles with diameters between 3.9 and 13.2 μm. The direct quantitative analysis of the Cu particle transferred onto a Si carrier gave a discrepancy between measured and calculated Cu amounts due to the absorption effects of incident and fluorescent X-rays within the particle. By the correction for the absorption effects, the Cu amounts in individual particles could be determined with the deviation within 10.5%. When the Cu particles were dissolved with HNO 3 solution prior to the TXRF analysis, the deviation was improved to be within 3.8%. In this case, no correction for the absorption effects was needed for quantification

Radiation chemical effects of X-rays on liquids

International Nuclear Information System (INIS)

Holroyd, R.A.; Preses, J.M.

1998-01-01

This review describes some of the chemical changes induced by photoelectrons which are released in liquids when X-rays are absorbed. Both experimental studies and theory are discussed. In part 1, the basic processes occurring upon absorption of X-rays are described. Parts 2 and 3 deal with hydrocarbon liquids; in part 2 the ion yields, including effects at K-edges, and in part 3, the yields of excited states. Part 4 discusses chemical effects of X-rays in aqueous solutions. The authors end with a summary of future needs and directions

X-ray photoelectron spectroscopy investigations of band offsets in Ga0.02Zn0.98O/ZnO heterojunction for UV photodetectors

Science.gov (United States)

Singh, Karmvir; Rawal, Ishpal; Punia, Rajesh; Dhar, Rakesh

2017-10-01

Here, we report the valence and conduction band offset measurements in pure ZnO and the Ga0.02Zn0.98O/ZnO heterojunction by X-Ray photoelectron spectroscopy studies for UV photodetector applications. For detailed investigations on the band offsets and UV photodetection behavior of Ga0.02Zn0.98O/ZnO heterostructures, thin films of pristine ZnO, Ga-doped ZnO (Ga0.02Zn0.98O), and heterostructures of Ga-doped ZnO with ZnO (Ga0.02Zn0.98O/ZnO) were deposited using a pulsed laser deposition technique. The deposited thin films were characterized by X-ray diffraction, atomic force microscopy, and UV-Vis spectroscopy. X-ray photoelectron spectroscopy studies were carried out on all the thin films for the investigation of valence and conduction band offsets. The valence band was found to be shifted by 0.28 eV, while the conduction band has a shifting of -0.272 eV in the Ga0.02Zn0.98O/ZnO heterojunction as compared to pristine ZnO thin films. All the three samples were analyzed for photoconduction behavior under UVA light of the intensity of 3.3 mW/cm2, and it was observed that the photoresponse of pristine ZnO (19.75%) was found to increase with 2 wt. % doping of Ga (22.62%) and heterostructured thin films (29.10%). The mechanism of UV photodetection in the deposited samples has been discussed in detail, and the interaction of chemisorbed oxygen on the ZnO surface with holes generated by UV light exposure has been the observed mechanism for the change in electrical conductivity responsible for UV photoresponse on the present deposited ZnO films.

Thorium effect on the oxidation of uranium: Photoelectron spectroscopy (XPS/UPS) and cyclic voltammetry (CV) investigation on (U1 − xThx)O2 (x = 0 to 1) thin films

NARCIS (Netherlands)

Cakir, P.; Eloirdi, R; Huber, F.; Konings, R.J.M.; Gouder, T

2017-01-01

Thin films of U_1− xTh_xO₂ (x = 0 to 1) have been deposited via reactive DC sputter technique and characterized by X-ray/Ultra-violet Photoelectron Spectroscopy (XPS/UPS), X-ray Powder Diffractometer (XRD) and Cyclic Voltammetry (CV) in order to understand the

X-ray photoelectron spectra and electronic structure of quasi-one-dimensional SbSeI crystals

Directory of Open Access Journals (Sweden)

J.Grigas

2007-01-01

Full Text Available The paper presents the X-ray photoelectron spectra (XPS of the valence band (VB and of the principal core levels from the (110 and (001 crystal surfaces for the quasi-one-dimensional high permittivity SbSeI single crystal isostructural to ferroelectric SbSI. The XPS were measured with monochromatized Al Ka radiation in the energy range of 0-1400 eV at room temperature. The VB is located from 1.6 to 20 eV below the Fermi level. Experimental energies of the VB and core levels are compared with the results of theoretical ab initio calculations of the molecular model of the SbSeI crystal. The electronic structure of the VB is revealed. Shifts in the core-level binding energies of surface atoms relative to bulk ones, which show a dependency on surface crystallography, have been observed. The chemical shifts of the core levels (CL in the SbSeI crystal for the Sb, I and Se states are obtained.

X-ray photoelectron spectroscopy study and thermoelectric properties of Al-doped ZnO thin films

International Nuclear Information System (INIS)

Li Li; Fang Liang; Zhou Xianju; Liu Ziyi; Zhao Liang; Jiang Sha

2009-01-01

In this paper, high quality Al-doped ZnO (AZO) thin films were prepared by direct current (DC) reactive magnetron sputtering using a Zn target (99.99%) containing Al of 1.5 wt.%. The films obtained were characterized by X-ray photoelectron spectroscopy (XPS) and thermoelectric measurements. The XPS results reveal that Zn and Al exist only in oxidized state, while there are dominant crystal lattice and rare adsorbed oxygen for O in the annealed AZO thin films. The studies of thermoelectric property show a striking thermoelectric effect in the AZO thin films. On the one hand, the thermoelectromotive and magnetothermoelectromotive forces increase linearly with increasing temperature difference (ΔT). On the other hand, the thermoelectric power (TEP) decreases with the electrical resistance of the sample. But the TEP increases with the increase of temperature below 300 K, and it nearly does not change around room temperature. The experimental results also demonstrate that the annealing treatment increases TEP, while the external magnetic field degrades TEP.

X-ray photoelectron spectroscopic analysis of rice kernels and flours: Measurement of surface chemical composition.

Science.gov (United States)

Nawaz, Malik A; Gaiani, Claire; Fukai, Shu; Bhandari, Bhesh

2016-12-01

The objectives of this study were to evaluate the ability of X-ray photoelectron spectroscopy (XPS) to differentiate rice macromolecules and to calculate the surface composition of rice kernels and flours. The uncooked kernels and flours surface composition of the two selected rice varieties, Thadokkham-11 (TDK11) and Doongara (DG) demonstrated an over-expression of lipids and proteins and an under-expression of starch compared to the bulk composition. The results of the study showed that XPS was able to differentiate rice polysaccharides (mainly starch), proteins and lipids in uncooked rice kernels and flours. Nevertheless, it was unable to distinguish components in cooked rice samples possibly due to complex interactions between gelatinized starch, denatured proteins and lipids. High resolution imaging methods (Scanning Electron Microscopy and Confocal Laser Scanning Microscopy) were employed to obtain complementary information about the properties and location of starch, proteins and lipids in rice kernels and flours. Copyright © 2016. Published by Elsevier Ltd.

Band alignment of InGaZnO4/Si interface by hard x-ray photoelectron spectroscopy

International Nuclear Information System (INIS)

Lee, Kyeongmi; Kamiya, Toshio; Nomura, Kenji; Yanagi, Hiroshi; Ikenaga, Eiji; Sugiyama, Takeharu; Kobayashi, Keisuke; Hosono, Hideo

2012-01-01

Although amorphous InGaZnO 4 has intensively been studied for a semiconductor channel material of thin-film transistors in next-generation flat-panel displays, its electronic structure parameters have not been reported. In this work, the electron affinities (χ) and the ionization potentials (I p ) of crystalline and amorphous InGaZnO 4 (c-IGZO and a-IGZO) were measured using bulk-sensitive hard x-ray photoelectron spectroscopy. First, the χ and I p values of c-IGZO and a-IGZO thin films were estimated by aligning the Zn 2p 3/2 core level energies to a literature value for ZnO, which provided χ = 3.90 eV and I p = 7.58 eV for c-IGZO and 4.31 eV and 7.41 eV for a-IGZO. It was also confirmed that the escape depth of the photoelectrons excited by the photon energy of 5950.2 eV is 3.3 nm for a-IGZO and large enough for directly measuring the interface electronic structure using a-IGZO/c-Si heterojunctions. It provided the valence band offset of ∼2.3 eV, which agrees well with the above data. The present results substantiate that the a-IGZO/c-Si interface follows well the Schottky-Mott rule.

Utilization of the statistics techniques for the analysis of the XPS (X-ray photoelectron spectroscopy) and Auger electronic spectra's deconvolutions

International Nuclear Information System (INIS)

Puentes, M.B.

1987-01-01

For the analysis of the XPS (X-ray photoelectron spectroscopy) and Auger spectra, it is important to performe the peaks' separation and estimate its intensity. For this purpose, a methodology was implemented, including: a spectrum's filter; b) substraction of the base line (or inelastic background); c) deconvolution (separation of the distribution that integrates the spectrum) and d) error of calculation of the mean estimation, comprising adjustment quality tests. A software (FORTRAN IV plus) that permits to use the methodology proposed from the experimental spectra was implemented. The quality of the methodology was tested with simulated spectra. (Author) [es

X-ray photoelectron spectroscopy investigation of ion beam sputtered indium tin oxide films as a function of oxygen pressure during deposition

International Nuclear Information System (INIS)

Nelson, A.J.; Aharoni, H.

1987-01-01

X-ray photoelectron spectroscopy analysis was performed on ion beam sputter deposited films of indium tin oxide as a function of O 2 partial pressure during deposition. The oxygen partial pressure was varied over the range of 2.5 x 10 -6 --4.0 x 10 -5 Torr. Changes in composition as well as in the deconvoluted In 3d 5 /sub // 2 , Sn 3d 5 /sub // 2 , and O 1s core level spectra were observed and correlated with the variation of the oxygen partial pressure during deposition. Results show that the films become increasingly stoichiometric as P/sub =/ is increased and that the excess oxygen introduced during deposition is bound predominantly to the Sn and has little or no effect on the In--O bonding

Determination of non-ionic surfactants in technologic liquors and effluents by X-ray fluorescent spectrometry

International Nuclear Information System (INIS)

Dankowski, P.; Majda, J.

1977-01-01

The method has been worked out for determination of non-ionic surfactants in technological liquors and effluents, based on the X-ray fluorescent spectrometry with an initial concentration by means of the phosphomolybdic acid. The method is suitable for a quantitative determination of ethylene oxide adducts in a wide range of applicable concentrations, the trace-ones included. (M.Z.)

Structural origin of Si-2p core-level shifts from Si(100)-c[4x2] surface: A spectral x-ray photoelectron diffraction study

Energy Technology Data Exchange (ETDEWEB)

Chen, X.; Tonner, B.P. [Univ. of Wisconsin, Milwaukee, WI (United States); Denlinger, J. [Univ. of Wisconsin, Milwaukee, WI (United States)][Ernest Orlando Lawrence Berkeley National Lab., CA (United States)] [and others

1997-04-01

The authors have performed angle-resolved x-ray photoelectron diffraction (XPD) from a Si(100)-c(4x2) surface to study the structural origin of Si-2p core-level shifts. In the experiment, the highly resolved surface Si-2p core-level spectra were measured as a fine grid of hemisphere and photon energies, using the SpectroMicroscopy Facility {open_quotes}ultraESCA{close_quotes} instrument. By carefully decomposing the spectra into several surface peaks, the authors are able to obtain surface-atom resolved XPD patterns. Using a multiple scattering analysis, they derived a detailed atomic model for the Si(100)-c(4x2) surface. In this model, the asymmetric dimers were found tilted by 11.5 plus/minus 2.0 degrees with bond length of 2.32 plus/minus 0.05{angstrom}. By matching model XPD patterns to experiment, the authors can identify which atoms in the reconstructed surface are responsible for specific photoemission lines in the 2p spectrum.

Band offset in zinc oxy-sulfide/cubic-tin sulfide interface from X-ray photoelectron spectroscopy

Energy Technology Data Exchange (ETDEWEB)

Sanal, K.C.; Nair, P.K.; Nair, M.T.S., E-mail: mtsn@ier.unam.mx

2017-02-28

Highlights: • Zinc oxy-sulfide thin films, 175–240 nm, deposited by rf-sputtering from targets of ZnO + ZnS. • Oxygen content in thin films is enhanced 3–4 times compared with that in ZnO:ZnS targets. • Thin film ZnO{sub x}S{sub 1−x} with x = 0.88–0.27 and optical band gap 2.8–3.2 eV is suitable for solar cells. • The conduction band offset with SnS of cubic structure studied by XPS are +0.41 to −0.28 eV. - Abstract: Zinc oxy-sulfide, ZnO{sub x}S{sub 1−x}, has been found to provide better band alignment in thin film solar cells of tin sulfide of orthorhombic crystalline structure. Here we examine ZnO{sub x}S{sub 1−x}/SnS-CUB interface, in which the ZnO{sub x}S{sub 1−x} thin film was deposited by radio frequency (rf) magnetron sputtering on SnS thin film of cubic (CUB) crystalline structure with a band gap (E{sub g}) of 1.72 eV, obtained via chemical deposition. X-ray photoelectron spectroscopy provides the valence band maxima of the materials and hence places the conduction band offset of 0.41 eV for SnS-CUB/ZnO{sub 0.27}S{sub 0.73} and −0.28 eV for SnS-CUB/ZnO{sub 0.88}S{sub 0.12} interfaces. Thin films of ZnO{sub x}S{sub 1−x} with 175–240 nm in thickness were deposited from targets prepared with different ZnO to ZnS molar ratios. With the target of molar ratio of 1:13.4, the thin films are of composition ZnO{sub 0.27}S{sub 0.73} with hexagonal crystalline structure and with that of 1:1.7 ratio, it is ZnO{sub 0.88}S{sub 0.12}. The optical band gap of the ZnO{sub x}S{sub 1−x} thin films varies from 2.90 eV to 3.21 eV as the sulfur to zinc ratio in the film increases from 0.12:1 to 0.73:1 as determined from X-ray diffraction patterns. Thus, band offsets sought for absorber materials and zinc oxy-sulfide in solar cells may be achieved through a choice of ZnO:ZnS ratio in the sputtering target.

Electronic structure of Al- and Ga-doped ZnO films studied by hard X-ray photoelectron spectroscopy

Directory of Open Access Journals (Sweden)

M. Gabás

2014-01-01

Full Text Available Al- and Ga-doped sputtered ZnO films (AZO, GZO are semiconducting and metallic, respectively, despite the same electronic valence structure of the dopants. Using hard X-ray photoelectron spectroscopy we observe that both dopants induce a band in the electronic structure near the Fermi level, accompanied by a narrowing of the Zn 3d/O 2p gap in the valence band and, in the case of GZO, a substantial shift in the Zn 3d. Ga occupies substitutional sites, whereas Al dopants are in both substitutional and interstitial sites. The latter could induce O and Zn defects, which act as acceptors explaining the semiconducting character of AZO and the lack of variation in the optical gap. By contrast, mainly substitutional doping is consistent with the metallic-like behavior of GZO.

The determination, by x-ray-fluorescence spectrometry, of gold in activated charcoal

International Nuclear Information System (INIS)

Austen, C.E.

1977-01-01

A rapid method is described for the determination of gold in activated charcoal by X-ray-fluorescence spectrometry. Compensation for matrix effects is achieved by means of platinum that is added for use as an internal standard. Calibration is achieved by use of a series of synthetic standards that are made by the spiking of barren charcoal with gold and platinum. The limit of determination is about 8 p.p.m. of gold, and the relative standard deviation is 1,2 per cent at a concentration level of 2300 p.p.m

Measuring conditions for second order X-ray Bragg-spectrometry

International Nuclear Information System (INIS)

Dellith, J; Scheffel, A; Wendt, M

2014-01-01

The KL 2,3 (α) 1,2 -lines of 19 K, the L 3 M 4,5 (α) 1,2 -lines of 48 Cd, and the M 5 N 6,7 (α) 1,2 -lines of 92 U are lines of comparable energy in the region of approximately 3 keV. In none of these cases were we able to resolve the three doublets when recording the spectra in first order Bragg spectrometry using a PET crystal as the dispersing element. For the purpose of enhancing the resolving power of the spectrometer, the three α spectra were recorded in second order reflection, thereby transferring the lines into another spectral region dominated by X-ray quanta of half the energy. In order to achieve high net peak intensities as well as a high peak-to-background ratio and, consequently, a high level of detection capability, the discriminator settings should be optimized quite carefully. In this manner, we were able to resolve the three α doublets and estimate α 2 /α 1 intensity ratios. Inexplicably, current monographs, e.g., by Goldstein et al, do not contain any indications about the rational use of high order spectrometry. Only a few rather old monographs contain some hints in this regard

Valence and magnetic state of transition-metal and rare-earth ions in single-crystal multiferroics RMn{sub 2}O{sub 5} (R = Y, Bi, Eu, Gd) from X-ray photoelectron spectroscopy data

Energy Technology Data Exchange (ETDEWEB)

Kozakov, A.T. [Scientific-Research Institute of Physics at Southern Federal University, 194 Stachki, Rostov-na-Donu 344194 (Russian Federation); Kochur, A.G., E-mail: agk@rgups.ru [Rostov State University of Transport Communication, 2 Narodnogo Opolcheniya, Rostov-na-Donu 344038 (Russian Federation); Nikolsky, A.V.; Googlev, K.A.; Smotrakov, V.G.; Eremkin, V.V. [Scientific-Research Institute of Physics at Southern Federal University, 194 Stachki, Rostov-na-Donu 344194 (Russian Federation)

2011-11-15

Highlights: {yields} Single crystals RMn{sub 2}O{sub 5} (R = Y, Bi, Eu, Gd) and YMnO{sub 3} are grown. {yields} Core level XPS are measured and calculated with inclusion of temperature effect. {yields} Mn2p, Mn3s, R4s, and R4d (R = Eu, Gd) XPS are sensitive to valence and spin state. {yields} Paramagnetic moments per structural cell are estimated. - Abstract: Single crystals of orthorhombic multiferroics RMn{sub 2}O{sub 5} (R = Y, Bi, Eu, Gd), and of hexagonal manganite YMnO{sub 3} are grown. X-ray photoelectron spectra of the core levels of the Mn, Y, Bi, Eu, Gd, and O atoms in multiferroics are obtained at room temperature with the ESCALAB 250 microprobe system with monochromatization of the exciting X-ray radiation. X-ray photoelectron spectra of Mn2p, Mn3s, R4s, and R4d (R = Eu, Gd) levels are assigned based on one-configuration isolated-ion approximation calculations with taking the temperature effect into account. It is shown using the photoelectron spectroscopy methods that both Mn{sup 3+} and Mn{sup 4+} ions are present in orthorhombic multiferroics, while Eu and Gd are in trivalent state. Paramagnetic moments per structural unit are calculated and compared with those determined from our spectroscopic data and with the data from other authors.

Ultrasensitive probing of the protein resistance of PEG surfaces by secondary ion mass spectrometry

DEFF Research Database (Denmark)

Kingshott, P.; McArthur, S.; Thissen, H.

2002-01-01

The highly sensitive surface analytical techniques X-ray photoelectron spectroscopy (XPS) and time-of-flight static secondary ion mass spectrometry (ToF-SIMS) were used to test the resistance of poly(ethylene glycol) (PEG) coatings towards adsorption of lysozyme (LYS) and fibronectin (FN). PEG co...

X-ray photoelectron and Auger electron spectroscopic study of the adsorption of molecular iodine on uranium metal and uranium dioxide

International Nuclear Information System (INIS)

Dillard, J.G.; Moers, H.; Klewe-Nebenius, H.; Kirch, G.; Pfennig, G.; Ache, H.J.

1984-01-01

The adsorption of molecular iodine on uranium metal and on uranium dioxide has been investigated at 25 0 C. Clean surfaces were prepared in an ultrahigh vacuum apparatus and were characterized by X-ray photoelectron (XPS) and X-ray and electron-induced Auger electron spectroscopies (AES). Adsorption of I 2 was studied for exposures up to 100 langmuirs (1 langmuir = 10 -6 torr s) on uranium metal and to 75 langmuirs on uranium dioxide. Above about 2-langmuir I 2 exposure on uranium, spectroscopic evidence is obtained to indicate the beginning of UI 3 formation. Saturation coverage for I 2 adsorption on uranium dioxide occurs at approximately 10-15 langmuirs. Analysis of the XPS and AES results as well as studies of spectra as a function of temperature lead to the conclusions that a dissociative chemisorption/reaction process occurs on uranium metal while nondissociative adsorption occurs on uranium dioxide. Variations in the iodine Auger kinetic energy and in the Auger parameter are interpreted in light of extra-atomic relaxation processes. 42 references, 10 figures, 1 table

Photoelectron spectra and electronic structure of some spiroborate complexes

Energy Technology Data Exchange (ETDEWEB)

Vovna, V.I.; Tikhonov, S.A.; Lvov, I.B., E-mail: lvov.ib@dvfu.ru; Osmushko, I.S.; Svistunova, I.V.; Shcheka, O.L.

2014-12-15

Highlights: • The electronic structure of three spiroborate complexes—boron 1,2-dioxyphenylene β-diketonates has been investigated. • UV and X-ray photoelectron spectra have been interpreted. • DFT calculations have been used for interpretation of spectral bands. • The binding energy of nonequivalent carbon and oxygen atoms were measured. • The structure of X-ray photoelectron spectra of the valence electrons is in good agreement with the energies and composition of Kohn–Sham orbitals. - Abstract: The electronic structure of the valence and core levels of three spiroborate complexes – boron 1,2-dioxyphenylene β-diketonates – has been investigated by methods of UV and X-ray photoelectron spectroscopy and quantum chemical density functional theory. The ionization energy of π- and n-orbitals of the dioxyphenylene fragment and β-diketonate ligand were measured from UV photoelectron spectra. This made it possible to determine the effect of substitution of one or two methyl groups by the phenyl in diketone on the electronic structure of complexes. The binding energy of nonequivalent carbon and oxygen atoms were measured from X-ray photoelectron spectra. The results of calculations of the energy of the valence orbitals of complexes allowed us to refer bands observed in the spectra of the valence electrons to the 2s-type levels of carbon and oxygen.

The X-ray spectrometry Si(Li) system and it's application in quantitative analysis of rare-earth elements

International Nuclear Information System (INIS)

Barbosa, J.B.S.

1985-11-01

The basic principles involved in Si(Li) system used in X-ray spectrometry is described. It also demonstrates its application in the energy range where the resolution is better than that characteristic of conventional spectrometers. The theoretical principles underlying the interaction between the electromagnetic radiation and matter, and a review on semiconductors are presented at first. It emphasizes the fluorescence phenomenon and the process of photon detection by semiconductor crystals whose properties and characteristics allow, in the specific case of Si-crystal, the confection of detectors with large sensitivity volume useful for X-ray spectrometry. In addition, the components of the Si(Li) system are described individually, with special attention to the operating aspects, and to the parameters affecting the quality of pulse height spectrum. Finally, the spectrometer performance is experimentally evaluated though the quantitative analyses of rare-earth element oxides (La, Ce, Pr, Nd). It should be stressed that this research indicates that the X-ray emission-transmission analysis is the most adequate method under the activation conditions provided by the spectrometer, where Am 241 emissor UPSILON of 60KeV is the photon source for the fluorescence. Therefore, the experimental work was extended in order to include all the necessary treatment. (Author) [pt

X-ray image intensifier tube and radiographic camera incorporating same

International Nuclear Information System (INIS)

1981-01-01

An X-ray sensitive image intensifier tube is described. It has an input window comprising at least one of iron, chromium and nickel for receiving an X-ray image. There is a flat scintillator screen adjacent for converting the X-ray image into a light pattern image. Adjacent to this is a flat photocathode layer for emitting photoelectrons in a pattern corresponding to the light pattern image. Parallel to this and spaced from it is a flat phosphor display screen. Electrostatic voltage is applied to the display screen and the photocathode layer to create an electric field between them to accelerate the photoelectrons towards the display screen. The paths of such parallel straight trajectories are governed solely by the electrostatic voltage applied, the image at the display screen being substantially equal in size to that of the X-ray image received at the input window. The tube envelope is preferably metallic to enable the basic components to be kept at a neutral potential and avoid spurious emissions. A radiographic camera with such an intensifier tube is also described. (U.K.)

Working with Detection Limits in X-Ray and Nuclear Spectrometry

International Nuclear Information System (INIS)

Van Espen, P.

2003-01-01

Full Text: Detection limits are important in many measurement procedures. Especially in analytical work we often need to take a decision about the presence or absence of a compound, or we need to guarantee that or instrument can detect the compound. Especially in regulatory work the concept of detection limits plays a crucial role. Data acquisition in x-ray and gamma-ray spectrometry is done by counting events for a preset time; hence the fluctuations in the observed spectra are governed by Poisson (counting) statistics. This makes the calculation of detection limits in principle very easy. However it is observed that there exists a great deal of confusion concerning the definition(s) and especially concerning the practical calculation and reporting of detection limits. In this contribution a simple but rigorous treatment of the concept of detection limits will be given, emphasizing on aspects such as a-priori and a-posterior i limits and on the effect of sample blank and instrumental blank in the calculation of the true detection limit. The problem of near zero background as observed in e.g. total reflection x-ray fluorescence analysis (T-XRF) and some low level counting applications will also be discussed. In this case Poisson statistics might not be applicable, affecting the decision limits with respect to the presence of absence of a signal. Finally handling data sets that contain detection limit values next to normal measured values, the so called problem of missing data will be discussed. Some suggestions to deal with this frequently occurring situation will be given

Changes of surface electron states of InP under soft X-rays irradiation

International Nuclear Information System (INIS)

Yang Zhian; Yang Zushen; Jin Tao; Qui Rexi; Cui Mingqi; Liu Fengqin

1999-01-01

Changes of surface electronic states of InP under 1 keV X-ray irradiation is studied by X-ray photoelectron spectroscopy (XPS) and ultraviolet ray energy spectroscopy (UPS). The results show that the soft X-ray irradiation has little effect on In atoms but much on P atoms. The authors analysed the mechanism of irradiation and explained the major effect

Handbook of X-Ray Data

CERN Document Server

Zschornack, Günter

2007-01-01

This sourcebook is intended as an X-ray data reference for scientists and engineers working in the field of energy or wavelength dispersive X-ray spectrometry and related fields of basic and applied research, technology, or process and quality controlling. In a concise and informative manner, the most important data connected with the emission of characteristic X-ray lines are tabulated for all elements up to Z = 95 (Americium). This includes X-ray energies, emission rates and widths as well as level characteristics such as binding energies, fluorescence yields, level widths and absorption edges. The tabulated data are characterized and, in most cases, evaluated. Furthermore, all important processes and phenomena connected with the production, emission and detection of characteristic X-rays are discussed. This reference book addresses all researchers and practitioners working with X-ray radiation and fills a gap in the available literature.

X-Ray photoelectron spectroscopy analysis of plasma-polymer interactions for development of low-damage plasma processing of soft materials

International Nuclear Information System (INIS)

Setsuhara, Yuichi; Cho, Ken; Shiratani, Masaharu; Sekine, Makoto; Hori, Masaru

2010-01-01

Plasma-polymer interactions have been investigated using atomic force microscopy (AFM) and x-ray photoelectron spectroscopy (XPS) of polyethyleneterephthalate (PET) films, which have been exposed to argon plasmas driven by low-inductance antenna modules as a parameter of ion energy. The AFM images indicated that the argon plasma exposure exhibited a significant change in surface roughness. The XPS analyses suggested that the degradation of chemical bonding structure and/or bond scission of PET could be effectively suppressed in the plasma exposures with ion energies below 6 eV. However, significant degradations of O = C-O bond, C-O bond and phenyl group were observed with increasing ion energy above 6 eV.

Atomic structure determination of InSb(100)c(4x4) and c(8x2)phases by X-ray photoelectron diffraction

International Nuclear Information System (INIS)

Carvalho, V.E. de; Soares, E.A.; Magalhaes, M.R.P.; Paniago, R.; Siervo, A. de; Landers, R.

2004-01-01

Full text: The (100) surfaces of III-V compound semiconductors exhibit a variety of surface reconstructions that have attracted a lot of attention because of their importance in both homo epitaxial and heteroepitaxial growth. In the special case of the narrow bandgap InSb compound semiconductor its potential application in high-speed electronic and optoelectronic devices has encourage many studies of its (100) surface atomic structure. Among the reconstructions presented by the InSb(100) surface two of them have received more attention, that is, the observed well-ordered In-rich c(8x2) and Sb terminated c(4x4) surfaces. The c(8x2) structure can be obtained by exposing the surface to low energy ion bombardment and annealing, whereas the c(4x4) structure involves the chemisorption of Sb onto an already Sb-terminated surface. These two structures have been studied mainly by scanning tunneling microscopy (STM) and surface X-ray diffraction (SXRD) techniques and all the proposed models are based on the occurrence of group III (and/or V) blocks of dimmers occupying sites on the top or at subsurface layer. However, there are still difficulties in determining either the exact number of atoms in each dimmer or the number of dimmers in each block. With the goal of getting a better structure determination of the InSb(100) surface phases a photoelectron diffraction experiment (XPD) was carried out at LNLS where synchrotron and Al-K α radiations have been used. In the present work, the experimental and preliminary results of structure determination for both In Sn(100)c(8x2) and InSb(100)c(4x4) phases will be presented and discussed. (author)

Band alignment of TiO2/FTO interface determined by X-ray photoelectron spectroscopy: Effect of annealing

Directory of Open Access Journals (Sweden)

Haibo Fan

2016-01-01

Full Text Available The energy band alignment between pulsed-laser-deposited TiO2 and FTO was firstly characterized using high-resolution X-ray photoelectron spectroscopy. A valence band offset (VBO of 0.61 eV and a conduction band offset (CBO of 0.29 eV were obtained across the TiO2/FTO heterointerface. With annealing process, the VBO and CBO across the heterointerface were found to be -0.16 eV and 1.06 eV, respectively, with the alignment transforming from type-I to type-II. The difference in the band alignment is believed to be dominated by the core level down-shift of the FTO substrate, which is a result of the oxidation of Sn. Current-voltage test has verified that the band alignment has a significant effect on the current transport of the heterojunction.

Femtosecond profiling of shaped x-ray pulses

Science.gov (United States)

Hoffmann, M. C.; Grguraš, I.; Behrens, C.; Bostedt, C.; Bozek, J.; Bromberger, H.; Coffee, R.; Costello, J. T.; DiMauro, L. F.; Ding, Y.; Doumy, G.; Helml, W.; Ilchen, M.; Kienberger, R.; Lee, S.; Maier, A. R.; Mazza, T.; Meyer, M.; Messerschmidt, M.; Schorb, S.; Schweinberger, W.; Zhang, K.; Cavalieri, A. L.

2018-03-01

Arbitrary manipulation of the temporal and spectral properties of x-ray pulses at free-electron lasers would revolutionize many experimental applications. At the Linac Coherent Light Source at Stanford National Accelerator Laboratory, the momentum phase-space of the free-electron laser driving electron bunch can be tuned to emit a pair of x-ray pulses with independently variable photon energy and femtosecond delay. However, while accelerator parameters can easily be adjusted to tune the electron bunch phase-space, the final impact of these actuators on the x-ray pulse cannot be predicted with sufficient precision. Furthermore, shot-to-shot instabilities that distort the pulse shape unpredictably cannot be fully suppressed. Therefore, the ability to directly characterize the x-rays is essential to ensure precise and consistent control. In this work, we have generated x-ray pulse pairs via electron bunch shaping and characterized them on a single-shot basis with femtosecond resolution through time-resolved photoelectron streaking spectroscopy. This achievement completes an important step toward future x-ray pulse shaping techniques.

A novel probe of intrinsic electronic structure: hard X-ray photoemission spectroscopy

International Nuclear Information System (INIS)

Takata, Y.; Tamasaku, K.; Nishino, Y.; Miwa, D.; Yabashi, M.; Ikenaga, E.; Horiba, K.; Arita, M.; Shimada, K.; Namatame, H.; Nohira, H.; Hattori, T.; Soedergren, S.; Wannberg, B.; Taniguchi, M.; Shin, S.; Ishikawa, T.; Kobayashi, K.

2005-01-01

We have realized hard X-ray (HX) photoemission spectroscopy (PES) with high throughput and high-energy resolution for core level and valence band studies using high-energy and high-brilliance synchrotron radiation at SPring-8. This is a brand new method because large escape depth of high-energy photoelectrons enables us to probe intrinsic bulk states free from surface condition. By use of a newly developed electron energy analyzer and well-focused X-rays, high-energy resolution of 75 meV (E/ΔE 79,000) was realized for 5.95 keV photoelectrons

The X-ray electronic spectra of TiC-NbC solid solution

International Nuclear Information System (INIS)

Cherkashenko, V.M.; Ezhov, A.V.; Nazarova, S.Z.; Kurmaev, Eh.Z.; Nojmann, M.

2001-01-01

X-ray photoelectronic spectra of inner levels and valency lands in TiC-NbC solid solutions were studied. Results of combining TiL α -, NbL β2.15 -, CK α - X-ray emission spectra and photoelectronic spectra of valency bands in one energy scale in reference to the Fermi level were analyzed. It is shown that a change in crystal lattice parameters, as well as charge redistribution between titanium and niobium atoms, produce a strong effect on electronic structure formation in the mixed carbides mentioned [ru

Molar concentration-depth profiles at the solution surface of a cationic surfactant reconstructed with angle resolved X-ray photoelectron spectroscopy

International Nuclear Information System (INIS)

Wang Chuangye; Morgner, Harald

2011-01-01

In the current work, we first reconstructed the molar fraction-depth profiles of cation and anion near the surface of tetrabutylammonium iodide dissolved in formamide by a refined calculation procedure, based on angle resolved X-ray photoelectron spectroscopy experiments. In this calculation procedure, both the transmission functions of the core levels and the inelastic mean free paths of the photoelectrons have been taken into account. We have evaluated the partial molar volumes of surfactant and solvent by the densities of such solutions with different bulk concentrations. With those partial molar volumes, the molar concentration-depth profiles of tetrabutylammonium ion and iodide ion were determined. The surface excesses of both surfactant ions were then achieved directly by integrating these depth profiles. The anionic molar concentration-depth profiles and surface excesses have been compared with their counterparts determined by neutral impact ion scattering spectroscopy. The comparisons exhibit good agreements. Being capable of determining molar concentration-depth profiles of surfactant ions by core levels with different kinetic energies may extend the applicable range of ARXPS in investigating solution surfaces.

The determination, by x-ray-fluorescence spectrometry, of gold, silver, and base metals on activated carbon

International Nuclear Information System (INIS)

Wall, G.; Jacobs, J.J.; Dixon, K.

1980-01-01

The method proposed involves ashing of the sample at a low temperature in a muffle furnace, mixing of the ash with alumina and boric acid in a Siebtechnik mill, and briquetting of the mixture. The elements are measured in the briquette by the use of x-ray fluorescence spectrometry. The detailed laboratory method is given in an appendix [af

Investigation of the chemistry of the dielectric/FeCoTb interface by x-ray photoelectron spectroscopy and Auger electron spectroscopy

International Nuclear Information System (INIS)

Stickle, W.F.; Coulman, D.

1987-01-01

The interfacial chemistry of magneto-optic structures of sputter deposited SiO, SiO 2 , Si 3 N 4 /FeCoTb/SiO, SiO 2 , and Si 3 N 4 was studied in detail by x-ray photoelectron spectroscopy (XPS) and Auger electron spectroscopy (AES). XPS and AES depth profiles have revealed a substantial amount of redox chemistry at the dielectric/rare-earth transition metal interfaces. The chemical reactions occur preferentially with the terbium as revealed in the XPS portion of the study by the formation of terbium oxide and terbium silicide. In the case of Si 3 N 4 evidence of TbN/sub x/ has also been observed. ''As deposited'' and annealed samples of the magneto-optic structures are compared and contrasted. It is concluded that Si 3 N 4 is a superior dielectric for magneto-optic media

Dynamic light scattering and X-ray photoelectron spectroscopy characterization of PEGylated polymer nanocarriers: internal structure and surface properties.

Science.gov (United States)

Celasco, Edvige; Valente, Ilaria; Marchisio, Daniele L; Barresi, Antonello A

2014-07-22

In this work, nanospheres and nanocapsules are precipitated in confined impinging jet mixers through solvent displacement and characterized. Acetone and water are used as the solvent and antisolvent, respectively, together with polymethoxypolyethylene glycol cyanoacrylate-co-hexadecylcyanoacrylate and Miglyol as the copolymer and oil, respectively. Characterization is performed with dynamic light scattering, with electrophoretic measurements, and for the first time with X-ray photoelectron spectroscopy. Results show that the presence of polyethylene glycol chains seems to be more pronounced on the surface of nanospheres than on that of nanocapsules. The thickness of the copolymer layer in nanocapsules ranges from 1 to 10 nm, depending on the value of the oil:copolymer mass ratio. Fast dilution is confirmed to have a positive effect in suppressing aggregation but can induce further copolymer precipitation.

X-ray radiation effects in multilayer epitaxial graphene

Energy Technology Data Exchange (ETDEWEB)

Hicks, Jeremy; Tinkey, Holly; Hankinson, John; Heer, Walt A. de; Conrad, Edward H. [School of Physics, Georgia Institute of Technology, Atlanta, Georgia 30332 (United States); Arora, Rajan; Kenyon, Eleazar; Chakraborty, Partha S.; Cressler, John D. [School of Electrical and Computer Engineering, Georgia Institute of Technology, Atlanta, Georgia 30332 (United States); Berger, Claire [School of Physics, Georgia Institute of Technology, Atlanta, Georgia 30332 (United States); CNRS-Institut Neel, BP 166, 38042 Grenoble Cedex 9 (France)

2011-12-05

We characterize multilayer graphene grown on C-face SiC before and after exposure to a total ionizing dose of 12 Mrad(SiO{sub 2}) using a 10 keV x-ray source. While we observe the partial peeling of the top graphene layers and the appearance of a modest Raman D-peak, we find that the electrical characteristics (mobility, sheet resistivity, free carrier concentration) of the material are mostly unaffected by radiation exposure. Combined with x-ray photoelectron spectroscopy data showing numerous carbon-oxygen bonds after irradiation, we conclude that the primary damage mechanism is through surface etching from reactive oxygen species created by the x-rays.

Development and applications of grazing exit micro X-ray fluorescence instrument using a polycapillary X-ray lens

International Nuclear Information System (INIS)

Emoto, T.; Sato, Y.; Konishi, Y.; Ding, X.; Tsuji, K.

2004-01-01

A polycapillary X-ray lens is an effective optics to obtain a μm-size X-ray beam for micro-X-ray fluorescence spectrometry (μ-XRF). We developed a μ-XRF instrument using a polycapillary X-ray lens, which also enabled us to perform Grazing Exit μ-XRF (GE-μ-XRF). The evaluated diameter of the primary X-ray beam was 48 μm at the focal distance of the X-ray lens. Use of this instrument enabled two-dimensional mapping of the elemental distributions during growth of the plant 'Quinoa'. The results of the mapping revealed elemental transition during growth. In addition, a small region of thin film was analyzed by GE-μ-XRF. We expect that GE-μ-XRF will become an effective method of estimating the film thickness of a small region

Present status of research and development on X-ray microprobe

International Nuclear Information System (INIS)

Koike, Masaki; Suzuki, I.H.

1991-01-01

X-ray beam micro-analysis has advanced rapidly in these years in conjunction with the development of powerful X-ray sources. Among a variety of methods being attempted, the method using a collimated narrow beam has been important because of high brightness, and of usability in both regions of soft and hard X-rays. In the soft X-ray region, the focused beam is formed by a fresnel zone plate or a Schwaltzschild mirror assembly, and can be used for scanning transmission microscope or scanning photoelectron microscope. In the hard X-ray region, the beam is formed by grazing incidence mirrors, and can be used for X-ray fluorescence micro-analysis for obtaining elemental mapping. In this report, the recent progress on the soft X-ray scanning microscopy and the X-ray microprobe has been surveyed, together with the improvement on the related optical elements. (author) 84 refs

Study of CeOx, PrOx, and CexPr1-xO2-δ films on Si(111) by means of high-energetic X-ray photoelectron spectroscopy

International Nuclear Information System (INIS)

Allahgholi, Aschkan

2013-03-01

The intention of this work is to shed light on two much discussed topics in the study of rare earth oxides (REO) by hard x-ray photoelectron spectroscopy (HAXPES): (i) Due to the complex spectral shape of the Ce3d region, there have been many discussions on proper approaches to determine the concentration of Ce 3+ and Ce 4+ species in CeO x over the last decades. (ii) Recently, the true electron structure of rare earth oxides gained new attention, since ab initio calculations showed the necessity of considering additional inter atomic charge transfer to Ce5d levels. Using HAXPES and resonant HAXPES, the question of the true electronic structure of rare earth oxides is approached from the experimental side. As a third topic, the obtained results for cerium oxide and praseodymium oxide are applied in order to investigate the plasma oxidized mixed oxide Ce x Pr 1-x O 2-δ grown on Si(111) during thermal reduction. (orig.)

Radiobiology of ultrasoft X-rays

International Nuclear Information System (INIS)

Raju, M.R.; Carpenter, S.; Chmielewski, J.; Schillaci, M.; Wilder, M.

1985-01-01

The goal of this program is to elucidate the principal physical, chemical, and biological mechanisms of radiation action in cells. The basic experiments for this program involve selected low- and high-energy x-ray sources and include studies of cell killing, both with and without modifiers (for example, hypoxia), determination of cellular age response, and measurement of induced DNA strand breaks, mutations, and chromosome aberrations. The theoretical effort involves Monte Carlo-based radiation track simulation codes to generate energy-deposition events and to follow the subsequent diffusion of chemical species. By combining the experimental and theoretical results, the authors plan to test assumptions used in existing models and to determine important parameters that should be included in any model. Ultrasoft x-rays (less than a few kiloelectron volts) provide a unique tool for studying induced biological lesions because x-rays produce photoelectrons with ranges much shorter than cellular dimensions but equivalent to the size of DNA strands and metaphase chromosomes

X-ray spectromicroscopy studies of protein-polymer Interactions

International Nuclear Information System (INIS)

Hitchcock, A.P.; Tyliszczak, T.; Heng, Y.M.; Cornelius, R.; Brash, J.L.; Ade, H.; Anders, S.; Scholl, A.; Nolting, F.

2000-01-01

Identification of the sites of protein binding on laterally heterogeneous polymer surfaces can help understand mechanisms of bio-passivation, which in turn has practical impact on developing improved polymers for medical uses, such as blood contact applications. We have used scanning X-ray transmission microscopy and photoelectron emission microscopy to explore the sensitivity of these X-ray microscopies to detection of human serum albumin adsorbed onto the surface of two different polyurethane polymers. Both techniques appear capable of the requisite monolayer sensitivity

Bulk sensitive hard x-ray photoemission electron microscopy

Energy Technology Data Exchange (ETDEWEB)

Patt, M., E-mail: m.patt@fz-juelich.de; Wiemann, C. [Peter Grünberg Institute (PGI-6) and JARA-FIT, Research Center Jülich, D-52425 Jülich (Germany); Weber, N.; Escher, M.; Merkel, M. [Focus GmbH, Neukirchner Str. 2, D-65510 Hünstetten (Germany); Gloskovskii, A.; Drube, W. [DESY Photon Science, Deutsches Elektronen-Synchrotron, D-22603 Hamburg (Germany); Schneider, C. M. [Peter Grünberg Institute (PGI-6) and JARA-FIT, Research Center Jülich, D-52425 Jülich (Germany); Fakultät f. Physik and Center for Nanointegration Duisburg-Essen (CeNIDE), Universität Duisburg-Essen, D-47048 Duisburg (Germany)

2014-11-15

Hard x-ray photoelectron spectroscopy (HAXPES) has now matured into a well-established technique as a bulk sensitive probe of the electronic structure due to the larger escape depth of the highly energetic electrons. In order to enable HAXPES studies with high lateral resolution, we have set up a dedicated energy-filtered hard x-ray photoemission electron microscope (HAXPEEM) working with electron kinetic energies up to 10 keV. It is based on the NanoESCA design and also preserves the performance of the instrument in the low and medium energy range. In this way, spectromicroscopy can be performed from threshold to hard x-ray photoemission. The high potential of the HAXPEEM approach for the investigation of buried layers and structures has been shown already on a layered and structured SrTiO{sub 3} sample. Here, we present results of experiments with test structures to elaborate the imaging and spectroscopic performance of the instrument and show the capabilities of the method to image bulk properties. Additionally, we introduce a method to determine the effective attenuation length of photoelectrons in a direct photoemission experiment.

Correlations Between Variations in Solar EUV and Soft X-Ray Irradiance and Photoelectron Energy Spectra Observed on Mars and Earth

Science.gov (United States)

Peterson, W. K.; Brain, D. A.; Mitchell, D. L.; Bailey, S. M.; Chamberlin, P. C.

2013-01-01

Solar extreme ultraviolet (EUV; 10-120 nm) and soft X-ray (XUV; 0-10 nm) radiation are major heat sources for the Mars thermosphere as well as the primary source of ionization that creates the ionosphere. In investigations of Mars thermospheric chemistry and dynamics, solar irradiance models are used to account for variations in this radiation. Because of limited proxies, irradiance models do a poor job of tracking the significant variations in irradiance intensity in the EUV and XUV ranges over solar rotation time scales when the Mars-Sun-Earth angle is large. Recent results from Earth observations show that variations in photoelectron energy spectra are useful monitors of EUV and XUV irradiance variability. Here we investigate photoelectron energy spectra observed by the Mars Global Surveyor (MGS) Electron Reflectometer (ER) and the FAST satellite during the interval in 2005 when Earth, Mars, and the Sun were aligned. The Earth photoelectron data in selected bands correlate well with calculations based on 1 nm resolution observations above 27 nm supplemented by broadband observations and a solar model in the 0-27 nm range. At Mars, we find that instrumental and orbital limitations to the identifications of photoelectron energy spectra in MGS/ER data preclude their use as a monitor of solar EUV and XUV variability. However, observations with higher temporal and energy resolution obtained at lower altitudes on Mars might allow the separation of the solar wind and ionospheric components of electron energy spectra so that they could be used as reliable monitors of variations in solar EUV and XUV irradiance than the time shifted, Earth-based, F(10.7) index currently used.

Correlations between variations in solar EUV and soft X-ray irradiance and photoelectron energy spectra observed on Mars and Earth

Science.gov (United States)

Peterson, W. K.; Brain, D. A.; Mitchell, D. L.; Bailey, S. M.; Chamberlin, P. C.

2013-11-01

extreme ultraviolet (EUV; 10-120 nm) and soft X-ray (XUV; 0-10 nm) radiation are major heat sources for the Mars thermosphere as well as the primary source of ionization that creates the ionosphere. In investigations of Mars thermospheric chemistry and dynamics, solar irradiance models are used to account for variations in this radiation. Because of limited proxies, irradiance models do a poor job of tracking the significant variations in irradiance intensity in the EUV and XUV ranges over solar rotation time scales when the Mars-Sun-Earth angle is large. Recent results from Earth observations show that variations in photoelectron energy spectra are useful monitors of EUV and XUV irradiance variability. Here we investigate photoelectron energy spectra observed by the Mars Global Surveyor (MGS) Electron Reflectometer (ER) and the FAST satellite during the interval in 2005 when Earth, Mars, and the Sun were aligned. The Earth photoelectron data in selected bands correlate well with calculations based on 1 nm resolution observations above 27 nm supplemented by broadband observations and a solar model in the 0-27 nm range. At Mars, we find that instrumental and orbital limitations to the identifications of photoelectron energy spectra in MGS/ER data preclude their use as a monitor of solar EUV and XUV variability. However, observations with higher temporal and energy resolution obtained at lower altitudes on Mars might allow the separation of the solar wind and ionospheric components of electron energy spectra so that they could be used as reliable monitors of variations in solar EUV and XUV irradiance than the time shifted, Earth-based, F10.7 index currently used.

Full k-space visualization of photoelectron diffraction

International Nuclear Information System (INIS)

Denlinger, J.D.; Rotenberg, E.; Kevan, S.D.; Tonner, B.P.

1997-01-01

The development of photoelectron holography has promoted the need for larger photoelectron diffraction data sets in order to improve the quality of real-space reconstructed images (by suppressing transformational artifacts and distortions). The two main experimental and theoretical approaches to holography, the transform of angular distribution patterns for a coarse selection of energies or the transform of energy-scanned profiles for several directions, represent two limits to k-space sampling. The high brightness of third-generation soft x-ray synchrotron sources provides the opportunity to rapidly measure large high-density x-ray photoelectron diffraction (XPD) data sets with approximately uniform k-space sampling. In this abstract, the authors present such a photoelectron data set acquired for Cu 3p emission from Cu(001). Cu(001) is one of the most well-studied systems for understanding photoelectron diffraction structure and for testing photoelectron holography methods. Cu(001) was chosen for this study in part due to the relatively inert and unreconstructed clean surface, and it served to calibrate and fine-tune the operation of a new synchrotron beamline, electron spectrometer and sample goniometer. In addition to Cu, similar open-quotes volumeclose quotes XPD data sets have been acquired for bulk and surface core-level emission from W(110), from reconstructed Si(100) and Si(111) surfaces, and from the adsorbate system of c(2x2) Mn/Ni(100)

The influence of biosurfactant adsorption on the physicochemical behaviour of carbon steel surfaces using contact angle measurements and X-ray photoelectron spectroscopy

Energy Technology Data Exchange (ETDEWEB)

Shubina, V., E-mail: varvara.shubina2014@gmail.com [LUNAM Université, IFSTTAR, MAST, SMC, F-44340 Bouguenais (France); Gaillet, L. [LUNAM Université, IFSTTAR, MAST, SMC, F-44340 Bouguenais (France); Ababou-Girard, S. [Institut de Physique de Rennes, Département Matériaux et Nanosciences, UMR 6251 CNRS, Université Rennes 1, 35000 Rennes-Cedex (France); Gaudefroy, V. [LUNAM Université, IFSTTAR, MAST, SMC, F-44340 Bouguenais (France); Chaussadent, T.; Farças, F. [Université Paris-Est, IFSTTAR, MAST, CPDM, F-77447 Marne-la-Vallée (France); Meylheuc, T. [INRA, UMR1319 Micalis, F-78352 Jouy-en-Josas (France); AgroParisTech, UMR Micalis, F-78352 Jouy-en-Josas (France); Dagbert, C. [2 Chemin de la Grand’côte, 36270 Éguzon-Chantôme (France); Creus, J. [LaSIE, UMR7356, Université de La Rochelle, Pôle Sciences et Technologie, Bâtiment Marie Curie, Avenue Michel Crépeau, 17000 La Rochelle (France)

2015-10-01

Highlights: • Surface modifications to carbon steel surfaces due to the adsorption of a biosurfactant derived from Pseudomonas fluorescens bacteria cells were investigated using contact angle measurements (CAM) and X-ray photoelectron spectroscopy (XPS). • CAM allowed to establish an increase of electron-donating properties of steel surface due to the biosurfactant adsorption. • XPS demonstrated that biosurfactant molecules change the stoichiometry of mixted-oxide layer and the new outer layer mostly composed of magnetite. • Thickness and density of adsorbed biosurfactants layers were highlighted using a semiquantitative approach for 3 different concentrations of biomolecules. - Abstract: We investigated modifications to carbon steel surfaces due to the adsorption of a biosurfactant derived from Pseudomonas fluorescens bacteria cells using contact angle measurements (CAM) and X-ray photoelectron spectroscopy (XPS). After conditioning carbon steel in solutions with three different concentrations of biosurfactant molecules: 0.05, 0.3 and 1 g L{sup −1}, the average thickness of the biosurfactant layer on the carbon steel specimens was 7.9 ± 0.3, 12.1 ± 0.5 and 16.4 ± 0.7 Å, respectively. The biosurfactants changed the composition of both the Fe{sup 2+} and Fe{sup 3+} mixed-oxide layer and the outer layer, mostly composed of Fe{sup 3+} associated with magnetite. Contact angle measurements indicate decreased hydrophobic properties after the carbon steel was modified by biosurfactant. It was shown that the carbon steel surface free energy depends on the biosurfactant concentration, due to an acquisition of strong electron-donating properties.

The influence of biosurfactant adsorption on the physicochemical behaviour of carbon steel surfaces using contact angle measurements and X-ray photoelectron spectroscopy

International Nuclear Information System (INIS)

Shubina, V.; Gaillet, L.; Ababou-Girard, S.; Gaudefroy, V.; Chaussadent, T.; Farças, F.; Meylheuc, T.; Dagbert, C.; Creus, J.

2015-01-01

Highlights: • Surface modifications to carbon steel surfaces due to the adsorption of a biosurfactant derived from Pseudomonas fluorescens bacteria cells were investigated using contact angle measurements (CAM) and X-ray photoelectron spectroscopy (XPS). • CAM allowed to establish an increase of electron-donating properties of steel surface due to the biosurfactant adsorption. • XPS demonstrated that biosurfactant molecules change the stoichiometry of mixted-oxide layer and the new outer layer mostly composed of magnetite. • Thickness and density of adsorbed biosurfactants layers were highlighted using a semiquantitative approach for 3 different concentrations of biomolecules. - Abstract: We investigated modifications to carbon steel surfaces due to the adsorption of a biosurfactant derived from Pseudomonas fluorescens bacteria cells using contact angle measurements (CAM) and X-ray photoelectron spectroscopy (XPS). After conditioning carbon steel in solutions with three different concentrations of biosurfactant molecules: 0.05, 0.3 and 1 g L −1 , the average thickness of the biosurfactant layer on the carbon steel specimens was 7.9 ± 0.3, 12.1 ± 0.5 and 16.4 ± 0.7 Å, respectively. The biosurfactants changed the composition of both the Fe 2+ and Fe 3+ mixed-oxide layer and the outer layer, mostly composed of Fe 3+ associated with magnetite. Contact angle measurements indicate decreased hydrophobic properties after the carbon steel was modified by biosurfactant. It was shown that the carbon steel surface free energy depends on the biosurfactant concentration, due to an acquisition of strong electron-donating properties

Surface study of stainless steel electrode deposition from soil electrokinetic (EK) treatment using X-ray photoelectron spectroscopy (XPS)

Energy Technology Data Exchange (ETDEWEB)

Embong, Zaidi, E-mail: zaidi@uthm.edu.my [Faculty of Science, Technology and Human Development, Universiti Tun Hussien Onn Malaysia (UTHM) 86400, Parit Raja, Batu, Johor (Malaysia); Research Centre for Soft Soils (RECESS), Office for Research, Innovation, Commercialization and Consultancy Management (ORICC), Universiti Tun Hussien Onn Malaysia UTHM 86400, Parit Raja, Batu, Johor (Malaysia); Johar, Saffuwan [Faculty of Science, Technology and Human Development, Universiti Tun Hussien Onn Malaysia (UTHM) 86400, Parit Raja, Batu, Johor (Malaysia); Tajudin, Saiful Azhar Ahmad [Research Centre for Soft Soils (RECESS), Office for Research, Innovation, Commercialization and Consultancy Management (ORICC), Universiti Tun Hussien Onn Malaysia UTHM 86400, Parit Raja, Batu, Johor (Malaysia); Sahdan, Mohd Zainizan [Microelectronics and Nanotechnology Centre (MiNT-SRC), Office for Research, Innovation, Commercialization and Consultancy Management (ORICC), Universiti Tun Hussien Onn Malaysia UTHM 86400, Parit Raja, Batu, Johor (Malaysia)

2015-04-29

Electrokinetic (EK) remediation relies upon application of a low-intensity direct current through the soil between stainless steel electrodes that are divided into a cathode array and an anode array. This mobilizes charged species, causing ions and water to move toward the electrodes. Metal ions and positively charged organic compounds move toward the cathode. Anions such as chloride, fluoride, nitrate, and negatively charged organic compounds move toward the anode. Here, this remediation techniques lead to a formation of a deposition at the both cathode and anode surface that mainly contributed byanion and cation from the remediated soil. In this research, Renggam-Jerangau soil species (HaplicAcrisol + RhodicFerralsol) with a surveymeter reading of 38.0 ± 3.9 μR/hr has been investigation in order to study the mobility of the anion and cation under the influence electric field. Prior to the EK treatment, the elemental composition of the soil and the stainless steel electrode are measured using XRF analyses. Next, the soil sample is remediated at a constant electric potential of 30 V within an hour of treatment period. A surface study for the deposition layer of the cathode and anode using X-ray Photoelectron spectroscopy (XPS) revealed that a narrow photoelectron signal from oxygen O 1s, carbon, C 1s silica, Si 2p, aluminium, Al 2p and chromium, Cr 2p exhibited on the electrode surface and indicate that a different in photoelectron intensity for each element on both electrode surface. In this paper, the mechanism of Si{sup 2+} and Al{sup 2+} cation mobility under the influence of voltage potential between the cathode and anode will be discussed in detail.

Surface study of stainless steel electrode deposition from soil electrokinetic (EK) treatment using X-ray photoelectron spectroscopy (XPS)

International Nuclear Information System (INIS)

Embong, Zaidi; Johar, Saffuwan; Tajudin, Saiful Azhar Ahmad; Sahdan, Mohd Zainizan

2015-01-01

Electrokinetic (EK) remediation relies upon application of a low-intensity direct current through the soil between stainless steel electrodes that are divided into a cathode array and an anode array. This mobilizes charged species, causing ions and water to move toward the electrodes. Metal ions and positively charged organic compounds move toward the cathode. Anions such as chloride, fluoride, nitrate, and negatively charged organic compounds move toward the anode. Here, this remediation techniques lead to a formation of a deposition at the both cathode and anode surface that mainly contributed byanion and cation from the remediated soil. In this research, Renggam-Jerangau soil species (HaplicAcrisol + RhodicFerralsol) with a surveymeter reading of 38.0 ± 3.9 μR/hr has been investigation in order to study the mobility of the anion and cation under the influence electric field. Prior to the EK treatment, the elemental composition of the soil and the stainless steel electrode are measured using XRF analyses. Next, the soil sample is remediated at a constant electric potential of 30 V within an hour of treatment period. A surface study for the deposition layer of the cathode and anode using X-ray Photoelectron spectroscopy (XPS) revealed that a narrow photoelectron signal from oxygen O 1s, carbon, C 1s silica, Si 2p, aluminium, Al 2p and chromium, Cr 2p exhibited on the electrode surface and indicate that a different in photoelectron intensity for each element on both electrode surface. In this paper, the mechanism of Si 2+ and Al 2+ cation mobility under the influence of voltage potential between the cathode and anode will be discussed in detail

Development and applications of grazing exit micro X-ray fluorescence instrument using a polycapillary X-ray lens

Energy Technology Data Exchange (ETDEWEB)

Emoto, T.; Sato, Y.; Konishi, Y.; Ding, X.; Tsuji, K. E-mail: tsuji@a-chem.eng.osaka-cu.ac.jp

2004-08-31

A polycapillary X-ray lens is an effective optics to obtain a {mu}m-size X-ray beam for micro-X-ray fluorescence spectrometry ({mu}-XRF). We developed a {mu}-XRF instrument using a polycapillary X-ray lens, which also enabled us to perform Grazing Exit {mu}-XRF (GE-{mu}-XRF). The evaluated diameter of the primary X-ray beam was 48 {mu}m at the focal distance of the X-ray lens. Use of this instrument enabled two-dimensional mapping of the elemental distributions during growth of the plant 'Quinoa'. The results of the mapping revealed elemental transition during growth. In addition, a small region of thin film was analyzed by GE-{mu}-XRF. We expect that GE-{mu}-XRF will become an effective method of estimating the film thickness of a small region.

Investigation of the near-surface structures of polar InN films by chemical-state-discriminated hard X-ray photoelectron diffraction

International Nuclear Information System (INIS)

Yang, A. L.; Yamashita, Y.; Kobata, M.; Yoshikawa, H.; Sakata, O.; Kobayashi, K.; Matsushita, T.; Píš, I.; Imura, M.; Yamaguchi, T.; Nanishi, Y.

2013-01-01

Near-surface structures of polar InN films were investigated by laboratory-based hard X-ray photoelectron diffraction (HXPD) with chemical-state-discrimination. HXPD patterns from In 3d 5/2 and N 1s core levels of the In-polar and N-polar InN films were different from each other and compared with the simulation results using a multiple-scattering cluster model. It was found that the near-surface structure of the In-polar InN film was close to the ideal wurtzite structure. On the other hand, on the N-polar InN film, defects-rich surface was formed. In addition, the existence of the In-polar domains was observed in the HXPD patterns.

Complementary low energy ion scattering and X-ray photoelectron spectroscopy characterization of polystyrene submitted to N{sub 2}/H{sub 2} glow discharge

Energy Technology Data Exchange (ETDEWEB)

Bonatto, F., E-mail: bonatto02@yahoo.com.br [Instituto de Fisica, Universidade Federal do Rio Grande do Sul, Porto Alegre, Rio Grande do Sul 91509-900 (Brazil); Rovani, S. [Universidade de Caxias do Sul, Caxias do Sul, Rio Grande do Sul 95070-560 (Brazil); Kaufmann, I.R.; Soares, G.V. [Instituto de Fisica, Universidade Federal do Rio Grande do Sul, Porto Alegre, Rio Grande do Sul 91509-900 (Brazil); Baumvol, I.J.R. [Instituto de Fisica, Universidade Federal do Rio Grande do Sul, Porto Alegre, Rio Grande do Sul 91509-900 (Brazil); Universidade de Caxias do Sul, Caxias do Sul, Rio Grande do Sul 95070-560 (Brazil); Krug, C. [Instituto de Fisica, Universidade Federal do Rio Grande do Sul, Porto Alegre, Rio Grande do Sul 91509-900 (Brazil)

2012-02-15

Low energy ion scattering (LEIS) and X-ray photoelectron spectroscopy (XPS) were used to access the elemental composition and chemical bonding characteristics of polystyrene (PS) surfaces sequentially treated by corona and glow discharge (plasma) processing in N{sub 2}/H{sub 2} ambient. The latter has shown activity as suppressor of pathogenic Staphylococcus epidermidis biofilms. LEIS indicated that oxygen from the corona discharge process is progressively replaced by nitrogen at the PS surface. XPS shows C=N and N-C=O chemical groups as significant inhibitors of bacterial adhesion, suggesting application in medical devices.

Wettability of Oil-Producing Reservoir Rocks as Determined from X-ray Photoelectron Spectroscopy

Science.gov (United States)

Toledo; Araujo; Leon

1996-11-10

Wettability has a dominant effect in oil recovery by waterflooding and in many other processes of industrial and environmental interest. Recently, the suggestion has been made that surface science analytical techniques (SSAT) could be used to rapidly determine the wettability of reservoir materials. Here, we bring the capability of X-ray photoelectron spectroscopy (XPS) to bear on the wettability evaluation of producing reservoir rocks. For a suite of freshly exposed fracture surfaces of rocks we investigate the relationship between wettability and surface composition as determined from XPS. The classical wettability index as measured with the Amott-Harvey test is used here as an indicator of the wettability of natural sandstones. The XPS spectra of oil-wet surfaces of rocks reveal the existence of organic carbon and also of an "organic" silicon species, of the kind Si-CH relevant to silanes, having a well-defined binding energy which differs from that of the Si-O species of mineral grains. We provide quantifiable evidence that chemisorbed organic material on the pore surfaces defines the oil-wetting character of various reservoir sandstones studied here which on a mineralogic basis are expected to be water-wet. This view is supported by a strong correlation between C content of pore surfaces and rock wettability. The results also suggest a correlation between organic silicon content on the pore surfaces and rock hydrophobicity.

The study of x-ray photo-electron spectroscopy of 99mTc-RBC

International Nuclear Information System (INIS)

Song Chunyi

1994-01-01

99m Tc-RBC are widely used as visualization agents for a blood pool. In this research 99m Tc-RBC was prepared by in vivo labeling. The chemical state and changes of 99m Tc atoms in 99m Tc-RBC was determined by x-ray photo-electron spectroscopy (XPS). The stability of 99m Tc-RBC is best shown by the determination of XPS at one hour or at two hours after labeling. There are two ways of coordination of bonding of RBC and 99m Tc: One is the coordination of 99m Tc with the oxygen atom which carries a negative charge of the carboxyl radical on the polypeptide bond, the other is the coordination of 99m Tc with a sulfur atom which caries the negative charge of cysteine. From the E b value of 99m Tc-RBC 99m Tc 3d5/2, it can be inferred that 99m Tc of 99m Tc-RBC is less than a trivalent. At the same time, the results of the determination by XPS with the compounds containing 99 TcO 4 - , 99 Tc(V), 99 Tc(IV) and 99 Tc(III) show that the chemical shift is lowered as the reduction state is lowered. Experimental results coincide with theoretical inferences

An in situ near-ambient pressure X-ray Photoelectron Spectroscopy study of Mn polarised anodically in a cell with solid oxide electrolyte

International Nuclear Information System (INIS)

Bozzini, Benedetto; Amati, Matteo; Bocchetta, Patrizia; Dal Zilio, Simone; Knop-Gericke, Axel; Vesselli, Erik; Kiskinova, Maya

2015-01-01

This paper reports an in situ study of the anodic behavior of a model solid oxide electrolysis cell (SOEC) by means of near-ambient pressure X-ray Photoelectron Spectroscopy (XPS) combined with near edge X-ray absorption fine structure (NEXAFS) measurements. The focus is on the anodic surface chemistry of MnO x , a model anodic material already considered in cognate SOFC-related studies, during electrochemical operation in CO 2 , CO 2 /H 2 O and H 2 O ambients. The XPS and NEXAFS results we obtained, complemented by electrochemical measurements and SEM characterisation, reveal the chemical evolution of Mn under electrochemical control. MnO is the stable chemical form at open-circuit potential (OCP), while Mn 3 O 4 forms under anodic polarisation in all the investigated gas ambients. Carbon deposits are present on the Mn electrode at OCP, but they are readily oxidised under anodic conditions. Prolonged operation of the MnO x anode leads to pitting of the Mn films, damaging of the triple-phase boundary region and also to formation of discontinuities in the Mn patch. This is accompanied by chemical transformations of the electrolyte and formation of ZrC without impact on the surface chemistry of the Mn-based anode

Envelope composition of Salmonella typhimurium 395 MS and 395 MR10 assesses by X-ray photoelectron spectroscopy (ESCA)

International Nuclear Information System (INIS)

Magnusson, K.F.; Johansson, L.

1977-01-01

The Salmonella typhimurium 395 MS and MR10 bacteria and lipopolysaccharide (LPS) were studied by X-ray photoelectron spectroscopy with the aid of the ESCA technique for the in situ analysis of chemical elements (C, O and N) at the surface. The nitrogen peak was large in both bacteria implying the presence of protein in the very outer part of the bacterial envelope due to the surface-sensitive measurement. The nitrogen peak was larger in the MR10 than in the MS bacteria, presumably reflecting an increased exposure of proteins concomitantly with the reduction of the LPS in MR10. After corrections for background and sensitivity of detection the relative intensities of the peaks agreed appreciably well with the proposed chemical structure of the LPS, indicating that at least semiquantitative relationships between the elements were obtained. (author)

Band alignment of TiO{sub 2}/FTO interface determined by X-ray photoelectron spectroscopy: Effect of annealing

Energy Technology Data Exchange (ETDEWEB)

Fan, Haibo, E-mail: hbfan@nwu.edu.cn, E-mail: liusz@snnu.edu.cn [Key Laboratory of Applied Surface and Colloid Chemistry, National Ministry of Education, Shaanxi Engineering Lab for Advanced Energy Technology, School of Materials Science and Engineering, Shaanxi Normal University, Xi’an 710119 (China); School of Physics, Northwest University, Xi’an 710069 (China); Yang, Zhou; Ren, Xianpei; Gao, Fei [Key Laboratory of Applied Surface and Colloid Chemistry, National Ministry of Education, Shaanxi Engineering Lab for Advanced Energy Technology, School of Materials Science and Engineering, Shaanxi Normal University, Xi’an 710119 (China); Yin, Mingli [Key Laboratory of Applied Surface and Colloid Chemistry, National Ministry of Education, Shaanxi Engineering Lab for Advanced Energy Technology, School of Materials Science and Engineering, Shaanxi Normal University, Xi’an 710119 (China); School of Science, Xi’an Technological University, Xi’an, Shaanxi 710062 (China); Liu, Shengzhong, E-mail: hbfan@nwu.edu.cn, E-mail: liusz@snnu.edu.cn [Key Laboratory of Applied Surface and Colloid Chemistry, National Ministry of Education, Shaanxi Engineering Lab for Advanced Energy Technology, School of Materials Science and Engineering, Shaanxi Normal University, Xi’an 710119 (China); Dalian Institute of Chemical Physics, Dalian National Laboratory for Clean Energy, Chinese Academy of Sciences, Dalian, 116023 (China)

2016-01-15

The energy band alignment between pulsed-laser-deposited TiO{sub 2} and FTO was firstly characterized using high-resolution X-ray photoelectron spectroscopy. A valence band offset (VBO) of 0.61 eV and a conduction band offset (CBO) of 0.29 eV were obtained across the TiO{sub 2}/FTO heterointerface. With annealing process, the VBO and CBO across the heterointerface were found to be -0.16 eV and 1.06 eV, respectively, with the alignment transforming from type-I to type-II. The difference in the band alignment is believed to be dominated by the core level down-shift of the FTO substrate, which is a result of the oxidation of Sn. Current-voltage test has verified that the band alignment has a significant effect on the current transport of the heterojunction.

Heavy metal determination by X-rays spectrometry in superficial sediments at Havana Bay

International Nuclear Information System (INIS)

Gelen, Alina; Izquierdo, Walter; Lopez, Neivy; Corrales, Yasser; Casanova, Amaya O.; Diaz, Oscar; Manso, Maria V.; D'Alessandro, Katia; Reyes, Enma; Toledo, Carlos; Beltran, Jesus; Perez, Marlen; Ramirez, Marta; Soto, Jesus

2007-01-01

Havana Bay is a typical bag-type located in the Western-North Coast of the Republic of Cuba. Since 1980 it has been the object of a study for sea bottom rehabilitation and improvement of quality of the waters, where the final objective will be the recovery of the coastal and marine ecosystem. Thirteen surface samples of the Havana Bay (Cuba) were collected and analysed by X-Rays spectrometry. Some majority elements (Si, Ca, K, Na, S, Cl, Al, Fe, Mg, C and O) were measured by scanning electron microscopy (SEM) coupled with microanalysis to perform geomorphologic analysis. Nine elements (Ca, Fe, Ti, Mn, Cu, Zn, Sr, Zr and Pb) have been measured using an Energy Dispersive X-Ray Fluorescence (EDXRF) with a Si(Li) detector. Multivariate statistical was used for the analysis. The concentration levels showed this bay as the most polluted in Cuba. The highest contents of Cu, Zn and Pb were obtained in Atares and Marimelena Cove; these elements are indicators of urban as well as industrial pollution. (author)

Heavy metal determination by X-rays spectrometry in superficial sediments at Havana Bay

Energy Technology Data Exchange (ETDEWEB)

Gelen, Alina; Izquierdo, Walter; Lopez, Neivy; Corrales, Yasser; Casanova, Amaya O.; Diaz, Oscar; Manso, Maria V.; D' Alessandro, Katia [Institute for Applied Sciences and Technology, Havana (Cuba)], E-mail: alina@instec.cu; Reyes, Enma; Toledo, Carlos [Central Laboratory Criminology, Havana (Cuba); Beltran, Jesus; Perez, Marlen; Ramirez, Marta [Engineering Centre for Environmental Management of Bays and Coasts, Havana (Cuba)], E-mail: beltran@cimab.transnet.cu; Soto, Jesus [Universidad de Cantabria, Santander (Spain)], E-mail: sotoj@unican.es

2007-07-01

Havana Bay is a typical bag-type located in the Western-North Coast of the Republic of Cuba. Since 1980 it has been the object of a study for sea bottom rehabilitation and improvement of quality of the waters, where the final objective will be the recovery of the coastal and marine ecosystem. Thirteen surface samples of the Havana Bay (Cuba) were collected and analysed by X-Rays spectrometry. Some majority elements (Si, Ca, K, Na, S, Cl, Al, Fe, Mg, C and O) were measured by scanning electron microscopy (SEM) coupled with microanalysis to perform geomorphologic analysis. Nine elements (Ca, Fe, Ti, Mn, Cu, Zn, Sr, Zr and Pb) have been measured using an Energy Dispersive X-Ray Fluorescence (EDXRF) with a Si(Li) detector. Multivariate statistical was used for the analysis. The concentration levels showed this bay as the most polluted in Cuba. The highest contents of Cu, Zn and Pb were obtained in Atares and Marimelena Cove; these elements are indicators of urban as well as industrial pollution. (author)

A study on the fusion reactor - Development of x-ray spectrometer for diagnosis of tokamak plasma

Energy Technology Data Exchange (ETDEWEB)

Jang, Hong Young; Choi, Duk In; Seo, Sung Hun; Kwon, Gi Chung; Jun, Sang Jin; Heo, Sung Hoi; Lee, Chan Hui [Korea Advanced Institute of Science and Technolgoy, Taejon (Korea, Republic of)

1996-09-01

This report of research is on the development of X-ray Photo-Electron Spectrometer (PES) for diagnosis of tokamak plasma. The spectrometer utilizes the fact that the energy of photo-electron is given by the difference between the energy of X-ray and the binding energy of materials. In the research of this year, we constructed two spectrometers; one is operated in KAIST tokamak and the other in KT1 tokamak. In addition, we reviewed the characteristics of the x-ray filter, the photo-electric effect of carbon foils and the detection efficiency of MCP and x-ray radiation of plasma. We measured the x-ray radiation in tokamak and diagnosed the qualitative plasma parameters from the analysis of data. The major interesting plasma parameters, which we can diagnose with the spectrometer, are the electron temperature, Z{sub eff}, the spatial distribution of x-ray radiation and etc. 27 refs., 2 tabs., 20 figs. (author)

Investigating Surface and Interface Phenomena in LiFeBO3 Electrodes Using Photoelectron Spectroscopy Depth Profiling

DEFF Research Database (Denmark)

Maibach, Julia; Younesi, Reza; Schwarzburger, Nele

2014-01-01

The formation of surface and interface layers at the electrodes is highly important for the performance and stability of lithium ion batteries. To unravel the surface composition of electrode materials, photoelectron spectroscopy (PES) is highly suitable as it probes chemical surface and interface...... properties with high surface sensitivity. Additionally, by using synchrotron-generated hard x-rays as excitation source, larger probing depths compared to in-house PES can be achieved. Therefore, the combination of in-house soft x-ray photoelectron spectroscopy and hard x-ray photoelectron spectroscopy...

Ultrafast X-Ray Spectroscopy of Conical Intersections

Science.gov (United States)

Neville, Simon P.; Chergui, Majed; Stolow, Albert; Schuurman, Michael S.

2018-06-01

Ongoing developments in ultrafast x-ray sources offer powerful new means of probing the complex nonadiabatically coupled structural and electronic dynamics of photoexcited molecules. These non-Born-Oppenheimer effects are governed by general electronic degeneracies termed conical intersections, which play a key role, analogous to that of a transition state, in the electronic-nuclear dynamics of excited molecules. Using high-level ab initio quantum dynamics simulations, we studied time-resolved x-ray absorption (TRXAS) and photoelectron spectroscopy (TRXPS) of the prototypical unsaturated organic chromophore, ethylene, following excitation to its S2(π π*) state. The TRXAS, in particular, is highly sensitive to all aspects of the ensuing dynamics. These x-ray spectroscopies provide a clear signature of the wave packet dynamics near conical intersections, related to charge localization effects driven by the nuclear dynamics. Given the ubiquity of charge localization in excited state dynamics, we believe that ultrafast x-ray spectroscopies offer a unique and powerful route to the direct observation of dynamics around conical intersections.

X-Ray Fluorescence Spectrometry. II Determination of Uranium in ores; Espectrometria de fluorescencia de Rayos X. II-Aplicacion a la determinacion de uranio en minerales

Energy Technology Data Exchange (ETDEWEB)

Bermudez Polonio, J; Crus Castillo, F. de la; Fernandez Cellini, R

1961-07-01

A method of analysis of uranium in ores by X-ray spectrometry was developed, using the internal standard technique. Strontium was found to be the most suitable internal standard for general use. A Norelco Philips X-ray fluorescent spectrometer was used in this work, equipped with a lithium fluoride crystal acting as a diffraction grating analyzer. The intensity of the uranium-L {alpha}{sub 1} spectral line is calculated and related to corresponding strontium-K{sub {alpha}} spectral line, both detected with a Scintillation Counter. (Author) 31 refs.

X-ray photoelectron spectroscopy of rice husk surface modified with maleated polypropylene and silane

International Nuclear Information System (INIS)

Park, B.-D.; Wi, Seung Gon; Lee, Kwang Ho; Singh, A.P.; Yoon, Tae-Ho; Kim, Y.S.

2004-01-01

Rice husks were subjected to dry-grinding and steam-explosion to reduce their sizes. Subsequently, the surface of rice husk particles was modified using two different coupling agents, maleated polypropylene (MAPP) and γ-aminopropyltriethoxysilane (γ-APS, A-1100) to induce chemical reactions between the husk surface and the coupling agents used. The modified surface properties of rice husk were examined using X-ray photoelectron spectroscopy and FT-IR spectroscopy. Dry grinding, a simple method of fracturing husk, provided particulate segments, while steam explosion separated husk into fibrous components. When treated with MAPP, the O/C ratio of the husk surface decreased for both dry ground and steam-exploded husk. The γ-APS treatment resulted in an increase in the Si/O ratio for dry ground husk surface while this ratio decreased for steam-exploded husk particles. These results indicated that both coupling agents might be linked to the husk surface through chemical reactions. FT-IR results also supported the occurrence of ester and ether bonds after treatment of husks with MAPP and γ-APS. The present work suggested that the method of preparing rice husk particles had a great impact on their surface properties, and would therefore affect the interfacial adhesion in rice husk-thermoplastic composites

Developments in expert systems for automatic examination of samples by X-ray photoelectron spectroscopy

International Nuclear Information System (INIS)

Castle, J.E.

2010-01-01

A brief introduction establishes the need for automatic interrogation of the X-ray photoelectron spectrum (XPS) during acquisition, to provide, immediately, the type of information required by users from a wide range of disciplines in science and technology. The review of progress in achieving this shows that progress has been made in demonstrating the use of simple Rules to extract useful information from the survey scan and to manipulate this to, for example, estimate contamination and film thicknesses on a surface. However it is argued that the essential next step is to establish a data base of the information that users from the differing fields expect to obtain from their use of XPS. Some examples of what the information might be is given for a number of fields such as Adhesion Science, Catalyst surfaces, and Bio-Systems. It is suggested that this list should be greatly expanded to provide the information in the form of Goals, each representing a relatively small step in interpretation of the data so as to achieve the required characterisation of the surface. Finally an example is given, by way of verification of a Rule base for metals and alloys, of how information in the survey scan compares with that obtained from curve fitted, high resolution, scans through individual peaks.

Characterization of Roman glass tesserae from the Coriglia excavation site (Italy) via energy-dispersive X-ray fluorescence spectrometry and Raman spectroscopy

Energy Technology Data Exchange (ETDEWEB)

Donais, Mary Kate; Sparks, Andrew; Redente, Monica [Saint Anselm College, Department of Chemistry, Manchester, NH (United States); Pevenage, Jolien van; Moens, Luc; Vincze, Laszlo [Ghent University, Department of Analytical Chemistry, Ghent (Belgium); George, David B. [Saint Anselm College, Department of Classics, Manchester, NH (United States); Vandenabeele, Peter [Ghent University, Department of Archaeology, Ghent (Belgium)

2016-12-15

The combined use of handheld energy-dispersive X-ray fluorescence spectrometry, Raman spectroscopy, and micro-energy-dispersive X-ray fluorescence spectrometry permitted the characterization of Roman glass tesserae excavation from the Coriglia (Italy) archeological site. Analyses of ten different glass colors were conducted as spot analyses on intact samples and as both spot analyses and line scans on select cross-sectioned samples. The elemental and molecular information gained from these spectral measurements allowed for the qualitative chemical characterization of the bulk glass, decolorants, opacifiers, and coloring agents. The use of an antimony opacifier in many of the samples supports the late Imperial phasing as determined through numismatic, fresco, ceramics, and architectural evidence. And dealinization of the exterior glass layers caused by the burial environment was confirmed. (orig.)

Application of neutron activation techniques and x-ray energy dispersion spectrometry, in analysis of metallic traces adsorbed by chelex-100 resin

International Nuclear Information System (INIS)

Fernandes, Jair C.; Amaral, Angela M.; Magalhaes, Jesus C.; Pereira, Jose S.J.; Silva, Juliana B. da; Auler, Lucia M.L.A.

2000-01-01

In this work, the authors have investigated optimal conditions of adsorption for several ion metallic groups (cations of heavy metals and transition metals, oxyanions metallics and metalloids and cations of rare earths), as traces (ppb), withdrawn and in mixture of groups, by chelex-100 resin. The experiments have been developed by bath techniques in ammonium acetate tamponade solution 40 mM pH 5,52 content 0,5 g of chelex-100 resin. After magnetic agitation for two hours, resins were dried and submitted to X-ray energy dispersion spectrometry, x-ray fluorescence spectrometry and neutron activation analysis. The results have demonstrated that chelex-100 resin adsorb quantitatively transition element groups and rare earth groups in two cases (withdrawn and simultaneously adsorption)

Locally resolved investigation of wedged Cu(In,Ga)Se{sub 2} films prepared by physical vapor deposition using hard X-ray photoelectron and X-ray fluorescence spectroscopy

Energy Technology Data Exchange (ETDEWEB)

Calvet, Wolfram, E-mail: wolfram.calvet@helmholtz-berlin.de [Helmholtz-Zentrum Berlin, Hahn-Meitner-Platz 1, D-14109 Berlin (Germany); Ümsür, Bünyamin; Höpfner, Britta; Lauermann, Iver; Prietzel, Karsten; Kaufmann, Christan A.; Unold, Thomas [Helmholtz-Zentrum Berlin, Hahn-Meitner-Platz 1, D-14109 Berlin (Germany); Lux-Steiner, Martha C. [Helmholtz-Zentrum Berlin, Hahn-Meitner-Platz 1, D-14109 Berlin (Germany); Freie Universität Berlin, Department of Physics, Arnimallee 14, D-14195 Berlin (Germany)

2015-05-01

We have investigated a specially grown Cu(In,Ga)Se{sub 2} (CIGSe) absorber, which was deposited by co-evaporation of Cu, In, Ga, and Se using a modified three stage process. Prior to the growth, the molybdenum-coated glass substrate was covered by a bent shroud made from tantalum (Ta), leading to a wedged absorber structure with a width of about 2 mm where the film thickness varies from 0 to 2 μm. In this region of interest the thickness dependency of morphology, concentration ratios and electronic properties was studied with secondary electron microscopy (SEM), X-ray fluorescence (XRF) and hard X-ray photoelectron spectroscopy (HAXPES), probing the CIGSe sample along the thickness gradient. The evidence of the thickness gradient itself was proven with SEM measurements in cross section geometry. By using XRF it was found that with decreasing film thickness the Cu concentration decreases significantly. This finding was also verified by HAXPES measurements. Furthermore, an enrichment of Ga towards the Mo back contact was found using the same technique. Besides these results the formation of a molybdenum selenide (MoSe) phase was observed on the fully covered part of the Mo coated substrate indicating a high mobility of Se on Mo under the given temperature conditions of the modified three stage deposition process. - Highlights: • Growth of a CIGSe wedge • Application of HAXPES and XRF as local probing techniques • Good agreement with former studies • Wedged CIGSe structures can be used for further, locally resolved experiments.

Three-Dimensional X-Ray Photoelectron Tomography on the Nanoscale: Limits of Data Processing by Principal Component Analysis

DEFF Research Database (Denmark)

Hajati, S.; Walton, J.; Tougaard, S.

2013-01-01

In a previous article, we studied the influence of spectral noise on a new method for three-dimensional X-ray photoelectron spectroscopy (3D XPS) imaging, which is based on analysis of the XPS peak shape [Hajati, S., Tougaard, S., Walton, J. & Fairley, N. (2008). Surf Sci 602, 3064-3070]. Here, we...... study in more detail the influence of noise reduction by principal component analysis (PCA) on 3D XPS images of carbon contamination of a patterned oxidized silicon sample and on 3D XPS images of Ag covered by a nanoscale patterned octadiene layer. PCA is very efficient for noise reduction, and using...... acquisition time. A small additional amount of information is obtained by using up to five PCA factors, but due to the increased noise level, this information can only be extracted if the intensity of the start and end points for each spectrum are obtained as averages over several energy points....

X-ray photoelectron spectroscopy and Auger electron spectroscopy studies on the passivation behavior of plasma-nitrided low alloy steel in nitric acid

Energy Technology Data Exchange (ETDEWEB)

Chyou, S.D.; Shih, H.C. (Dept. of Materials Science and Engineering, National Tsing Hua Univ., Hsinchu (Taiwan))

1991-12-14

Nitrided SAE 4140 steel has been passivated by concentrated nitric acid. The resulting film was characterized using a combination of surface-analytical techniques, such as X-ray photoelectron spectroscopy (XPS) to evaluate the chemical composition of the passive film. Auger electron spectroscopy (AES) combined with ion etching was used to determine the composition depth profiles of nitrided surface. It was found that preferential dissolution of iron leads to enhanced nitrogen and chromium concentrations within the oxynitrided layer. A dense protective oxynitrided layer was found to be formed on the nitrided surface when the concentration of nitric acid was as high as 8 M. The results of X-ray diffraction, XPS and AES analyses conclude that the protective nitride layer is composed of (Fe,Cr){sub 4}N, (Fe,Cr){sub 2-3}N and CrN in the inner layer, Fe{sub 2}O{sub 3}, Cr{sub 2}O{sub 3} and remnant nitrides in the middle layer and nitrides accompanying Cr(OH){sub 3}.H{sub 2}O and {gamma}'-FeOOH in the outermost layer. (orig.).

Multivariate statistical analysis for x-ray photoelectron spectroscopy spectral imaging: Effect of image acquisition time

International Nuclear Information System (INIS)

Peebles, D.E.; Ohlhausen, J.A.; Kotula, P.G.; Hutton, S.; Blomfield, C.

2004-01-01

The acquisition of spectral images for x-ray photoelectron spectroscopy (XPS) is a relatively new approach, although it has been used with other analytical spectroscopy tools for some time. This technique provides full spectral information at every pixel of an image, in order to provide a complete chemical mapping of the imaged surface area. Multivariate statistical analysis techniques applied to the spectral image data allow the determination of chemical component species, and their distribution and concentrations, with minimal data acquisition and processing times. Some of these statistical techniques have proven to be very robust and efficient methods for deriving physically realistic chemical components without input by the user other than the spectral matrix itself. The benefits of multivariate analysis of the spectral image data include significantly improved signal to noise, improved image contrast and intensity uniformity, and improved spatial resolution - which are achieved due to the effective statistical aggregation of the large number of often noisy data points in the image. This work demonstrates the improvements in chemical component determination and contrast, signal-to-noise level, and spatial resolution that can be obtained by the application of multivariate statistical analysis to XPS spectral images

Effect of Space Radiation Processing on Lunar Soil Surface Chemistry: X-Ray Photoelectron Spectroscopy Studies

Science.gov (United States)

Dukes, C.; Loeffler, M.J.; Baragiola, R.; Christoffersen, R.; Keller, J.

2009-01-01

Current understanding of the chemistry and microstructure of the surfaces of lunar soil grains is dominated by a reference frame derived mainly from electron microscopy observations [e.g. 1,2]. These studies have shown that the outermost 10-100 nm of grain surfaces in mature lunar soil finest fractions have been modified by the combined effects of solar wind exposure, surface deposition of vapors and accretion of impact melt products [1,2]. These processes produce surface-correlated nanophase Feo, host grain amorphization, formation of surface patinas and other complex changes [1,2]. What is less well understood is how these changes are reflected directly at the surface, defined as the outermost 1-5 atomic monolayers, a region not easily chemically characterized by TEM. We are currently employing X-ray Photoelectron Spectroscopy (XPS) to study the surface chemistry of lunar soil samples that have been previously studied by TEM. This work includes modification of the grain surfaces by in situ irradiation with ions at solar wind energies to better understand how irradiated surfaces in lunar grains change their chemistry once exposed to ambient conditions on earth.

Measurement of barrier height of Pd on diamond (100) surface by X-ray photoelectron spectroscopy

Energy Technology Data Exchange (ETDEWEB)

Li, F.N. [Institute of Wide Band Gap Semiconductors, Xi' an Jiaotong University, Xi' an 710049 (China); Nation Key Laboratory of ASIC, HSRI, Shijiazhuang 050051 (China); Liu, J.W. [International Center for Young Scientists, National Institute for Materials Science (NIMS), 1-1 Namiki, Tsukuba, Ibaraki 3050044 (Japan); Zhang, J.W.; Wang, X.L.; Wang, W.; Liu, Z.C. [Institute of Wide Band Gap Semiconductors, Xi' an Jiaotong University, Xi' an 710049 (China); Wang, H.X., E-mail: hxwangcn@mail.xjtu.edu.cn [Institute of Wide Band Gap Semiconductors, Xi' an Jiaotong University, Xi' an 710049 (China)

2016-05-01

Highlights: • Metal-semiconductor contacts of Pd/hydrogen-terminated diamond and Pd/oxygen-terminated diamond have been investigated by XPS measurements. • The barrier height for Pd/hydrogen-terminated diamond (ohmic contact) has been measured to be −0.27 eV. • The barrier height for Pd/oxygen-terminated diamond (Schottky contact) has been measured to be 1.73 eV. - Abstract: Barrier height (Φ{sub BH}) values for Pd/hydrogen-terminated diamond (H-diamond) and Pd/oxygen-terminated diamond (O-diamond) have been investigated by X-ray photoelectron spectroscopy technique. H-diamond and O-diamond have been formed on the same diamond (100) layer grown by microwave plasma-enhanced chemical vapor deposition,on which Pd layers have been evaporated. The Φ{sub BH} values for Pd/H-diamond and Pd/O-diamond are determined to be −0.27 eV and 1.73 eV, respectively. It indicates that Pd is a suitable metal for ohmic and Schottky contacts on H-diamond and O-diamond, respectively. The experimental Φ{sub BH} values are in good agreement with the theoretical calculation results.

Thickness measurement of SiO2 films thinner than 1 nm by X-ray photoelectron spectroscopy

International Nuclear Information System (INIS)

Joong Kim, Kyung; Park, Ki Tae; Lee, Jong Wan

2006-01-01

The thickness measurement of ultra-thin SiO 2 films thinner than 1 nm was studied by X-ray photoelectron spectroscopy (XPS). Amorphous SiO 2 thin films were grown on amorphous Si films to avoid the thickness difference due to the crystalline structure of a substrate. SiO 2 thin films were grown by ion beam sputter deposition under oxygen gas flow and the thickness was measured by in situ XPS. The attenuation length was determined experimentally by a SiO 2 film with a known thickness. The straight line fit between the measured thickness using XPS and the nominal thickness showed a good linear relation with a gradient of 0.969 and a small offset of 0.126 nm. The gradient measured at the range of 3.4-0.28 nm was very close to that measured at sub-nanometer range of 1.13-0.28 nm. This result means that the reliable measurement of SiO 2 film thickness below 1 nm is possible by XPS

Cu,Cr and As determination in preserved woods (Eucalyptus ssp.) by X-ray fluorescence spectrometries; Determinacao de cobre, cromo e arsenio em madeira preservada (Eucalyptus sp.) pelas espectrometrias de fluorescencia de raios X

Energy Technology Data Exchange (ETDEWEB)

Pereira Junior, Sergio Matias

2014-07-01

Brazil produces around 2.2 millions of cubic meters of treated wood to meet the annual demand of railway, electric, rural and construction sectors. The most used wood species are eucalyptus (Eucalyptus ssp.) and pine (Pinus ssp.).The treated woods used for poles, sleepers, fence posts and plywoods should be according to Brazilian norms requirements. The most usual wood preservative products used in Brazil are CCA (chromated copper arsenate) and CCB (copper chromium and boron salt). The analytical methods, such as flame atomic absorption spectrometry (FAAS), plasma inductively coupled optical emission spectrometry (ICPOES) and X-ray fluorescence spectrometry (XRFS) have been used for the analytical control of those treatment processes. In this work, the eucalyptus trees (Eucalyptus ssp) samples was obtained from Minas Gerais State, Brazil, cut plantation areas. Under pressure, eucalyptus wood samples were submitted to different concentration of CCA solution reaching 3.9, 6.7, 9.1, 12.4 and 14.0 kg of CCA by m-³ sapwood retentions. Samples in cylinders and sawdust forms were obtained from treated wood samples. Copper, chromium and arsenic determination was performed using the energy dispersive X-ray fluorescence spectrometry (EDXRFS), portable X-ray fluorescence spectrometry (PXRFS), flame atomic absorption spectrometry (FAAS) and instrumental neutron activation analysis. In this work, the method of analysis, sensitivity, precision and accuracy performances of the related techniques were outlined. (author)

Utilization of synchrotron radiation in analytical chemistry. Soft X-ray emission and absorption spectroscopy

International Nuclear Information System (INIS)

Muramatsu, Yasuji

2015-01-01

Synchrotron soft X-ray spectroscopy includes three major types of spectroscopy such as X-ray absorption spectroscopy (XAS), X-ray emission spectroscopy (XES), and X-ray photoelectron spectroscopy (XPS). This paper takes up XAS and XES of soft X-rays, and briefly describes the principle. XAS is roughly classified into XANES (X-ray absorption near-edge structure) and EXAFS (extended X-ray absorption fine structure), and XANES is mainly used in the analysis based on XAS of soft X-rays. As the examples of the latest soft X-ray analyses, the following are introduced: (1) bandgap of boron implantation diamond and the local structure of boron, (2) catalytic sites in solid fuel cell carbon electrode, and (3) soft X-ray analysis under atmospheric pressure. (A.O.)

Soft x-ray spectro microscope

International Nuclear Information System (INIS)

Campuzano, J.C.; Jennings, G.; Beaulaigue, L.; Rodricks, B.G.; Brizard, C.

1990-01-01

This paper reports on the development of an x-ray photoelectron microscope that provides spatial as well as chemical information on the nature of the sample. Photons from the Aladdin Synchrotron at the Synchrotron Radiation Center in Stoughton, WI are monochromatized by an extended-range Grasshopper monochromator covering the range 40 to 1500 eV with energy resolution varying between 10 and 200 MeV. The monochromatized radiation generates photoelectrons in the sample, which are energy-analyzed with a resolving power E|ΔE > 5 x 10 4 and imaged by a multichannel plate array. The visible image is transferred to a computer by a virtual-phase charge-coupled device camera with a dynamic range of 4096:1. Preliminary coarse measurements indicate a spatial resolution of the instrument of better than 1μm, although a limit of 600 Angstrom is possible. The instrument provides chemical shift-resolved images of low-lying core levels in a variety of samples

Photoelectron interference fringes by super intense x-ray laser pulses

International Nuclear Information System (INIS)

Toyota, Koudai; Morishita, Toru; Watanabe, Shinichi; Tolstikhin, Oleg I

2009-01-01

The photoelectron spectra of H - produced by circularly polarized strong high-frequency laser pulses are theoretically studied. An oscillating substructure in the above-threshold ionization (ATI) peaks is observed, which extends the validity of the earlier findings in the 1D calculations [K. Toyota et al., Phys. Rev. A 76, 043418 (2007)] and 3D calculations for linear polarization [O. I. Tolstikhin, Phys. Rev. A 77, 032712 (2008)]. Its origin is due to an interference between a pair of photoelectron wave packets created in the rising and falling part of the pulse, which appears clearly in the stabilization regime.

High-resolution x-ray photoemission spectra of silver

DEFF Research Database (Denmark)

Barrie, A.; Christensen, N. E.

1976-01-01

An electron spectrometer fitted with an x-ray monochromator for Al Kα1,2 radiation (1486.6 eV) has been used to record high-resolution x-ray photoelectron spectra for the 4d valence band as well as the 3d spin doublet in silver. The core-level spectrum has a line shape that can be described...... successfully in terms of the many-body theory of Mahan, Nozières, and De Dominicis. The 4d spectrum agrees well with predictions based on a relativistic-augmented-plane-wave band-structure calculation....

Atmospheric pressure X-ray photoelectron spectroscopy apparatus: Bridging the pressure gap

Energy Technology Data Exchange (ETDEWEB)

Velasco-Vélez, J. J., E-mail: velasco@fhi-berlin.mpg.de, E-mail: mh@fhi-berlin.mpg.de; Schlögl, R. [Department of Heterogeneous Reactions, Max Planck Institute for Chemical Energy Conversion, Mülheim an der Ruhr 45470 (Germany); Department of Inorganic Chemistry, Fritz-Haber-Institut der Max-Planck-Gesellschaft, Berlin 14195 (Germany); Pfeifer, V.; Algara-Siller, G.; Stotz, E.; Teschner, D.; Kube, P.; Knop-Gericke, A. [Department of Inorganic Chemistry, Fritz-Haber-Institut der Max-Planck-Gesellschaft, Berlin 14195 (Germany); Hävecker, M., E-mail: velasco@fhi-berlin.mpg.de, E-mail: mh@fhi-berlin.mpg.de; Skorupska, K. [Department of Heterogeneous Reactions, Max Planck Institute for Chemical Energy Conversion, Mülheim an der Ruhr 45470 (Germany); Wang, R.; Braeuninger-Weimer, P.; Hofmann, S. [Engineering Department, University of Cambridge, Cambridge CB3 0FA (United Kingdom); Centeno, A.; Zurutuza, A. [Graphenea, San Sebastian 20018 (Spain)

2016-05-15

One of the main goals in catalysis is the characterization of solid/gas interfaces in a reaction environment. The electronic structure and chemical composition of surfaces become heavily influenced by the surrounding environment. However, the lack of surface sensitive techniques that are able to monitor these modifications under high pressure conditions hinders the understanding of such processes. This limitation is known throughout the community as the “pressure gap.” We have developed a novel experimental setup that provides chemical information on a molecular level under atmospheric pressure and in presence of reactive gases and at elevated temperatures. This approach is based on separating the vacuum environment from the high-pressure environment by a silicon nitride grid—that contains an array of micrometer-sized holes—coated with a bilayer of graphene. Using this configuration, we have investigated the local electronic structure of catalysts by means of photoelectron spectroscopy and in presence of gases at 1 atm. The reaction products were monitored online by mass spectrometry and gas chromatography. The successful operation of this setup was demonstrated with three different examples: the oxidation/reduction reaction of iridium (noble metal) and copper (transition metal) nanoparticles and with the hydrogenation of propyne on Pd black catalyst (powder).

X-ray photoelectron spectroscopy and luminescent properties of Y{sub 2}O{sub 3}:Bi{sup 3+} phosphor

Energy Technology Data Exchange (ETDEWEB)

Jafer, R.M. [Department of Physics, University of the Free State, P.O. Box 339, Bloemfontein, ZA 9300 South Africa (South Africa); Department of Physics, Faculty of Education, University of Khartoum, P.O. Box 321, Postal Code 11115 Omdurman (Sudan); Coetsee, E., E-mail: CoetseeE@ufs.ac.za [Department of Physics, University of the Free State, P.O. Box 339, Bloemfontein, ZA 9300 South Africa (South Africa); Yousif, A. [Department of Physics, University of the Free State, P.O. Box 339, Bloemfontein, ZA 9300 South Africa (South Africa); Department of Physics, Faculty of Education, University of Khartoum, P.O. Box 321, Postal Code 11115 Omdurman (Sudan); Kroon, R.E.; Ntwaeaborwa, O.M.; Swart, H.C. [Department of Physics, University of the Free State, P.O. Box 339, Bloemfontein, ZA 9300 South Africa (South Africa)

2015-03-30

Highlights: • XPS results for high Bi concentration indicated the Bi 4f peaks inside the Y 3d energy range. • XPS also indicated the C{sub 2} and S{sub 6} sites in both Y{sub 2}O{sub 3} and Bi{sub 2}O{sub 3} that results in blue and green luminescence centers. • The false-color CL overlay results also proved the emission of the Bi{sup 3+} ion in the two different sites. - Abstract: X-ray photoelectron spectroscopy (XPS) results provided proof for the blue and green emission of Bi{sup 3+} in the Y{sub 2}O{sub 3}:Bi{sup 3+} phosphor. The Y{sub 2}O{sub 3}:Bi{sup 3+} phosphor was successfully prepared by the combustion process during the investigation of down-conversion materials for Si solar cell application. The X-ray diffraction (XRD) patterns indicated that a single-phase cubic crystal structure with the Ia3 space group was formed. X-ray photoelectron spectroscopy (XPS) showed that the Bi{sup 3+} ion replaces the Y{sup 3+} ion in two different coordination sites in the Y{sub 2}O{sub 3} crystal structure. The O 1s peak shows five peaks, two which correlate with the O{sup 2−} ion in Y{sub 2}O{sub 3} in the two different sites, two which correlate with O{sup 2−} in Bi{sub 2}O{sub 3} in the two different sites and the remaining peak relates to hydroxide. The Y 3d spectrum shows two peaks for the Y{sup 3+} ion in the Y{sub 2}O{sub 3} structure in two different sites and the Bi 4f spectrum shows the Bi{sup 3+} ion in the two different sites in Bi{sub 2}O{sub 3}. The photoluminescence (PL) results showed three broad emission bands in the blue and green regions under ultraviolet excitation, which were also present for panchromatic cathodoluminescence (CL) results. These three peaks have maxima at ∼3.4, 3.0 and 2.5 eV. The PL emission ∼3.0 eV (blue emission) showed two excitation bands centered at ∼3.7 and 3.4 eV while the PL emission at ∼2.5 eV (green emission) showed a broad excitation band from ∼4 to 3.4 eV. The panchromatic CL images were obtained

Test of atomic theory by photoelectron spectrometry with synchrotron radiation

International Nuclear Information System (INIS)

Krause, M.O.

1984-01-01

The successful combination of synchrotron radiation with electron spectrometry, accomplished at Daresbury, England and Orsay, France, made it possible to investigate sigma/sub x/ and β/sub x/ continuously over the very soft x-ray or the uv range of photon energies. The detailed and highly differentiated data resulting from this advanced experimentation put theory to a stringent test. In the interplay between theory and experiment, sophisticated Hartree Fock (HF) based models were developed which included both relativistic and many-electron effects. These theoretical models have provided us with a better insight than previously possible into the physics of the photon-atom interaction and the electronic structure and dynamics of atoms. However, critical experiments continue to be important for further improvements of theory. A number of such experiments are discussed in this presentation. The dynamic properties determined in these studies include in addition to sigma/sub x/ and β/sub x/ the spin polarization parameters. As a result the comparison between theory and experiment becomes rigorous, detailed and comprehensive. 46 references, 6 figures

Study by X-ray photoelectron spectroscopy (XPS) and radiochemistry (Cl36) of the interaction of chloride ions with a passive film formed on nickel

International Nuclear Information System (INIS)

Herbelin, Jean-Marc

1990-01-01

This research thesis reports the study of the influence of chlorides on nickel passivation by using a radiochemical method based on the use of the Cl 36 isotope and the X-ray photoelectron spectroscopy (XPS). The first one allows the in-situ determination of the adsorption of chlorides on the surface, or their inclusion in surface films during the electrochemical treatment. The XPS analysis allows the characterization of modifications induced by chlorides in passive films. The obtained results allow a better understanding in the interpretation of the mechanisms of corrosion induced by chloride ions [fr

Direct evaluation of electrical dipole moment and oxygen density ratio at high-k dielectrics/SiO2 interface by X-ray photoelectron spectroscopy analysis

Science.gov (United States)

Fujimura, Nobuyuki; Ohta, Akio; Ikeda, Mitsuhisa; Makihara, Katsunori; Miyazaki, Seiichi

2018-04-01

The electrical dipole moment at an ultrathin high-k (HfO2, Al2O3, TiO2, Y2O3, and SrO)/SiO2 interface and its correlation with the oxygen density ratio at the interface have been directly evaluated by X-ray photoelectron spectroscopy (XPS) under monochromatized Al Kα radiation. The electrical dipole moment at the high-k/SiO2 interface has been measured from the change in the cut-off energy of secondary photoelectrons. Moreover, the oxygen density ratio at the interface between high-k and SiO2 has been estimated from cation core-line signals, such as Hf 4f, Al 2p, Y 3d, Ti 2p, Sr 3d, and Si 2p. We have experimentally clarified the relationship between the measured electrical dipole moment and the oxygen density ratio at the high-k/SiO2 interface.

Determination of nickel in chloralkali electrolysis brines by X-ray fluorescence spectrometry on a membrane filter

International Nuclear Information System (INIS)

Andrade, L.L.; Minzl, E.

1984-01-01

X-ray fluorescence spectrometry after ammonium pyrrolidinedithiocarbamate (APDC) preconcentration is proposed for the determination of nickel in chloralkali electrolysis brines. The optimum conditions for the precipitation target tube, peak intensity, background, analysing crystal, counters and exposure time were investigated. The method was applied to chloralkali brines of evaporite salts (halite, sylvinite, carnallite and tachhydrite), sodium, potassium and magnesium salts, explored in Sergipe (Brazil), by Petrobras-Mineracao S.A.(Author) [pt

High gain gas microstrip detectors for soft x-ray detection

International Nuclear Information System (INIS)

Bateman, J.; Barlow, R.; Derbyshire, G.

2001-01-01

This report describes development work in which systematic changes in the pitch of the electrode pattern of a Gas Microstrip Detector are explored in the search for higher avalanche gains and enhanced stability. With the cathode width set to half of the pitch, gas gains of >50 000 are comfortably attainable with low detector noise so that x-rays can potentially be detected down to the limit of a single x-ray-produced photoelectron. (author)

Low-energy X-ray and gamma spectrometry using silicon photodiodes; Espectrometria de raios X e gama de baixa energia utilizando fotodiodos de silicio

Energy Technology Data Exchange (ETDEWEB)

Silva, Iran Jose Oliveira da

2000-08-01

The use of semiconductor detectors for radiation detection has increased in recent years due to advantages they present in comparison to other types of detectors. As the working principle of commercially available photodiodes is similar to the semiconductor detector, this study was carried out to evaluate the use of Si photodiodes for low energy x-ray and gamma spectrometry. The photodiodes investigated were SFH-205, SFH-206, BPW-34 and XRA-50 which have the following characteristics: active area of 0,07 cm{sup 2} and 0,25 cm{sup 2}, thickness of the depletion ranging from 100 to 200 {mu}m and junction capacitance of 72 pF. The photodiode was polarized with a reverse bias and connected to a charge sensitive pre-amplifier, followed by a amplifier and multichannel pulse analyzer. Standard radiation source used in this experiment were {sup 241} Am, {sup 109} Cd, {sup 57} Co and {sup 133} Ba. The X-ray fluorescence of lead and silver were also measured through K- and L-lines. All the measurements were made with the photodiodes at room temperature.The results show that the responses of the photodiodes very linear by the x-ray energy and that the energy resolution in FWHM varied between 1.9 keV and 4.4 keV for peaks corresponding to 11.9 keV to 59 keV. The BPW-34 showed the best energy resolution and the lower dark current. The full-energy peak efficiency was also determined and it was observed that the peak efficiency decreases rapidly above 50 keV. The resolution and efficiency are similar to the values obtained with other semiconductor detectors, evidencing that the photodiodes used in that study can be used as a good performance detector for low energy X-ray and gamma spectrometry. (author)

Assessment of the Quality of Newly Formed Bone around Titanium Alloy Implants by Using X-Ray Photoelectron Spectroscopy

Directory of Open Access Journals (Sweden)

Hiroshi Nakada

2012-01-01

Full Text Available The aim of this study was to evaluate differences in bones quality between newly formed bone and cortical bone formed around titanium alloy implants by using X-ray photoelectron spectroscopy. As a result of narrow scan measurement at 4 weeks, the newly formed bone of C1s, P2p, O1s, and Ca2p were observed at a different peak range and strength compared with a cortical bone. At 8 weeks, the peak range and strength of newly formed bone were similar to those of cortical bone at C1s, P2p, and Ca2p, but not O1s. The results from this analysis indicate that the peaks and quantities of each element of newly formed bone were similar to those of cortical bone at 8 weeks, suggestive of a strong physicochemical resemblance.

X-ray photoelectron spectroscopy analysis of cleaning procedures for synchrotron radiation beamline materials at the Advanced Photon Source

International Nuclear Information System (INIS)

Li, Y.; Ryding, D.; Liu, C.; Kuzay, T.M.; McDowell, M.W.; Rosenberg, R.A.

1994-01-01

TZM (a high temperature molybdenum alloy), machinable tungsten, and 304 stainless steel were cleaned using environmentally safe, commercially available cleaning detergents. The surface cleanliness was evaluated by x-ray photoelectron spectroscopy (XPS). It was found that a simple alkaline detergent is very effective at removal of organic and inorganic surface contaminants or foreign particle residue from machining processes. The detergent can be used with ultrasonic agitation at 140 F to clean the TZM molybdenum, machinable tungsten, and 304 stainless steel. A citric-acid-based detergent was also found to be effective at cleaning metal oxides, such as iron oxide, molybdenum oxide, as well as tungsten oxides at mild temperatures with ultrasonic agitation, and it can be used to replace strong inorganic acids to improve cleaning safety and minimize waste disposal and other environmental problems. The efficiency of removing the metal oxides depends on both cleaning temperature and time

Structure, Mobility, and Composition of Transition Metal Catalyst Surfaces. High-Pressure Scanning Tunneling Microscopy and Ambient-Pressure X-ray Photoelectron Spectroscopy Studies

Energy Technology Data Exchange (ETDEWEB)

Zhu, Zhongwei [Univ. of California, Berkeley, CA (United States)

2013-12-06

Surface structure, mobility, and composition of transition metal catalysts were studied by high-pressure scanning tunneling microscopy (HP-STM) and ambient-pressure X-ray photoelectron spectroscopy (AP-XPS) at high gas pressures. HP-STM makes it possible to determine the atomic or molecular rearrangement at catalyst surfaces, particularly at the low-coordinated active surface sites. AP-XPS monitors changes in elemental composition and chemical states of catalysts in response to variations in gas environments. Stepped Pt and Cu single crystals, the hexagonally reconstructed Pt(100) single crystal, and Pt-based bimetallic nanoparticles with controlled size, shape and composition, were employed as the model catalysts for experiments in this thesis.

Elements in normal and cirrhotic human liver. Potassium, iron, copper, zinc and bromine measured by X-ray fluorescence spectrometry

DEFF Research Database (Denmark)

Laursen, J.; Milman, N.; Leth, Peter Mygind

1990-01-01

Various elements (K, Fe, Cu, Zn, Br) were measured by X-ray flourescence spectrometry in cellular and connective tissue fractions of normal and cirrhotic liver samples obtained at autopsy. Normal livers: 32 subjects (16 males, 16 females) median age 69 years. Cirrhotic livers: 14 subjects (13 mal...

Secondary electronic processes and the structure of X-ray photoelectron spectra of lanthanides in oxygen-containing compounds

International Nuclear Information System (INIS)

Teterin, Yu.A.; Teterin, A.Yu.; Lebedev, A.M.; Ivanov, K.E.

2004-01-01

X-ray photoelectron spectra of lanthanide compounds in the binding energy range 0-1250 eV beside the spin-orbitally split doublets exhibit fine structure. In particular, in the low-energy spectral range 0-50 eV such structure appears most likely due to the formation of the inner (IVMO) and outer (OVMO) valence molecular orbitals. The many-body perturbation shows up in the spectra of all the studied electronic shells but with different probabilities, while the multiplet splitting and dynamic effect in the spectra of just some inner shells. The present work studies the X-ray photoelectron spectral structure of lanthanide (La-Lu except for Pm) oxides and orthoniobates due to the secondary electronic processes accompanying the photoemission from the inner shells: many-body perturbation and dynamic effect. As a result, for example, the relative intensity of the line due to the many-body perturbation (shake-up process) with ΔE sat ∼4 eV for LaNbO 4 was found to decrease with decreasing of the binding energy of the inner electrons from 0.72 (E b for La 3d 5/2 =834.8 eV) to 0.28 (E b for La 4d 5/2 =102.9 eV). The full-width at half-maximum of the Ln 3d 5/2 line of lanthanide oxides and orthoniobates decreases as the atomic number Z of lanthanide grows in the range 58≤Z≤67 to the middle of the lanthanide row, and then increases. This agrees with the fact that for the beginning of the lanthanide row the Ln 3d 5/2 photoemission is accompanied by the shake-up process, while for the second half of the row--by the shake-down. It is important to note that it is connected with the Ln 4f binding energy change relative to the OVMO in compounds. The present work also confirms experimentally that the dynamic effect due to the gigantic Coster-Kronig transitions observed in the Ln 4p spectra takes place within the inner Ln 4p, 4d and outer Ln 4f shells with formation of the additional two-hole final state Ln 4p 6 4d 8 4f n+1 . The influence of the chemical environment on the Ln 4

Solar X-ray bursts

International Nuclear Information System (INIS)

Urnov, A.M.

1980-01-01

In the popular form the consideration is given to the modern state tasks and results of X-ray spectrometry of solar bursts. The operation of X-ray spectroheliograph is described. Results of spectral and polarization measurings of X-ray radiation of one powerful solar burst are presented. The conclusion has been drawn that in the process of burst development three characteristic stages may be distingwished: 1) the initial phase; just in this period processes which lead to observed consequences-electromagnetic and corpuscular radiation are born; 2) the impulse phase, or the phase of maximum, is characterised by sharp increase of radiation flux. During this phase the main energy content emanates and some volumes of plasma warm up to high temperatures; 3) the phase of burst damping, during which plasma cools and reverts to the initial condition

Development of multilayer optics for X-ray broadband spectrometry of plasma emission

International Nuclear Information System (INIS)

Emprin, Benoit

2014-01-01

Within the framework of the research on inertial confinement fusion, the 'Commissariat a l'energie atomique et aux energies alternatives' has studied and implemented an absolute calibrated time-Resolved broadband soft x-Ray spectrometer, called 'Diagnostic de Mesure du rayonnement X'. This diagnostic, composed of 20 measurement channels, measures the emitted radiant power from a laser created plasma in the range from 50 eV to 20 keV. We have developed additional measurement channels to obtain redundancy and an improvement in measurement accuracy. The principle of these new channels is based on an original concept to obtain spectral bounded flat-Responses. Two channels have been developed for the 2 - 4 keV and 4 - 6 keV spectral ranges, using aperiodic multilayer mirrors made at the 'Laboratoire Charles Fabry' with Cr/Sc and Ni/W/SiC/W layers respectively. These mirrors were characterized at synchrotron radiation facilities and integrated into the spectrometer. The two new channels were used during laser-Plasma experimental campaigns at the OMEGA laser facility in Rochester (USA). This allowed us to determine directly the radiant power with only one measurement within a certain spectral band, and with a better precision when compared with using standard channels. The results, in good agreement with the standard measurement channels, allowed us to validate the use of aperiodic multilayer mirrors for X-Ray broadband spectrometry. (author) [fr

Summary of existing information on gamma-ray and X-ray attenuation coefficients of solutions

DEFF Research Database (Denmark)

Singh, K.; Gerward, Leif

2002-01-01

Accurate values of X-ray and gamma-ray attenuation coefficients of different chemicals are required in spectrometry as well as in many other scientific, engineering and medical disciplines involving photon radiation. The current state of knowledge of experimental and theoretical gamma-ray and X-r......-ray attenuation coefficients in aqueous solutions of salts is presented and exemplified by recent work. The results presented provide a basis for studying X-ray and gamma-ray photon interactions with ions in solution (hydrated ions) rather than ion compounds in solid form....

Determination of fluorine concentrations using wavelength dispersive X-ray fluorescence (WDXRF) spectrometry to analyze fluoride precipitates.

Science.gov (United States)

Lee, H. A.; Lee, J.; Kwon, E.; Kim, D.; Yoon, H. O.

2015-12-01

In recent times, fluorine has been receiving increasing attention due to the possibility for chemical (HF) leakage accidents and its high toxicity to human and environment. In this respect, a novel approach for the determination of fluorine concentrations in water samples using wavelength dispersive X-ray fluorescence (WDXRF) spectrometry was investigated in this study. The main disadvantage of WDXRF technique for fluorine analysis is low analytical sensitivity for light elements with atomic number (Z) less than 15. To overcome this problem, we employed the precipitation reaction which fluoride is reacted with cation such as Al3+ and/or Ca2+ prior to WDXRF analysis because of their high analytical sensitivity. The cation was added in fluoride solutions to form precipitate (AlF3 and/or CaF2) and then the solution was filtered through Whatman filter. After drying at 60 °C for 5 min, the filter was coated with X-ray film and directly analyzed using WDXRF spectrometry. Consequently, we analyzed the cation on filter and subsequently fluorine concentration was calculated inversely based on chemical form of precipitate. This method can improve the analytical sensitivity of WDXRF technique for fluorine analysis and be applicable to various elements that can make precipitate.

X-ray chemical analyzer for field applications

International Nuclear Information System (INIS)

Gamba, O.O.M.

1977-01-01

A self-supporting portable field multichannel x-ray chemical analyzer system is claimed. It comprises a lightweight, flexibly connected, remotely locatable, radioisotope-excited sensing probe utilizing a cryogenically-cooled solid state semi-conductor crystal detector for fast in situ non-destructive, qualitative and quantitative analysis of elements in solid, powder, liquid or slurried form, utilizing an x-ray energy dispersive spectrometry technique

Surface Analysis of Marine Sulphate-Reducing Bacteria Exo polymers on Steel During Bio corrosion Using X-ray Photoelectron Spectroscopy

International Nuclear Information System (INIS)

Fathul Karim Sahrani; Madzlan Abd. Aziz; Zaharah Ibrahim; Adibah Yahya

2008-01-01

The aim of this study was to determine the surface chemistry during bio corrosion process on growth and on the production of exo polymeric substances (EPS) in batch cultures of mix-strains of marine sulphate-reducing bacteria (SRB) isolated from Malaysian Shipyard and Engineering Harbours, Pasir Gudang. The EPS and precipitates were analyzed by x-ray photoelectron spectroscopy (XPS). The XPS results indicate that Fe(2p 3/2 ) spectrum for iron sulphide can be fitted with Fe(II) and Fe(III) components, both corresponding to Fe-S bond types. The absence of oxide oxygen in the O(1s) spectrum and Fe(III)-O bond types in the Fe(2p 3/2 ) spectrum supports the conclusion that iron sulphides are composed of both ferric and ferrous iron coordinated with mono sulphide and disulphide. (author)

Interatomic scattering in energy dependent photoelectron spectra of Ar clusters

Energy Technology Data Exchange (ETDEWEB)

Patanen, M.; Benkoula, S.; Nicolas, C.; Goel, A. [Synchrotron SOLEIL, L’Orme des Merisiers, Saint-Aubin, BP 48, 91192 Gif-sur-Yvette Cedex (France); Antonsson, E. [Synchrotron SOLEIL, L’Orme des Merisiers, Saint-Aubin, BP 48, 91192 Gif-sur-Yvette Cedex (France); Physikalische und Theoretische Chemie Institut für Chemie und Biochemie, Fachbereich Biologie, Chemie, Pharmazie, Freie Universität Berlin, Takustrasse 3, 14195 Berlin (Germany); Neville, J. J. [Synchrotron SOLEIL, L’Orme des Merisiers, Saint-Aubin, BP 48, 91192 Gif-sur-Yvette Cedex (France); Department of Chemistry, University of New Brunswick, Fredericton, New Brunswick E3B 6E2 (Canada); Miron, C., E-mail: Catalin.Miron@synchrotron-soleil.fr [Synchrotron SOLEIL, L’Orme des Merisiers, Saint-Aubin, BP 48, 91192 Gif-sur-Yvette Cedex (France); Extreme Light Infrastructure - Nuclear Physics (ELI-NP), ‘Horia Hulubei’ National Institute for Physics and Nuclear Engineering, 30 Reactorului Street, RO-077125 Măgurele, Jud. Ilfov (Romania)

2015-09-28

Soft X-ray photoelectron spectra of Ar 2p levels of atomic argon and argon clusters are recorded over an extended range of photon energies. The Ar 2p intensity ratios between atomic argon and clusters’ surface and bulk components reveal oscillations similar to photoelectron extended X-ray absorption fine structure signal (PEXAFS). We demonstrate here that this technique allows us to analyze separately the PEXAFS signals from surface and bulk sites of free-standing, neutral clusters, revealing a bond contraction at the surface.

Thickness measurement of a thin hetero-oxide film with an interfacial oxide layer by X-ray photoelectron spectroscopy

Science.gov (United States)

Kim, Kyung Joong; Lee, Seung Mi; Jang, Jong Shik; Moret, Mona

2012-02-01

The general equation Tove = L cos θ ln(Rexp/R0 + 1) for the thickness measurement of thin oxide films by X-ray photoelectron spectroscopy (XPS) was applied to a HfO2/SiO2/Si(1 0 0) as a thin hetero-oxide film system with an interfacial oxide layer. The contribution of the thick interfacial SiO2 layer to the thickness of the HfO2 overlayer was counterbalanced by multiplying the ratio between the intensity of Si4+ from a thick SiO2 film and that of Si0 from a Si(1 0 0) substrate to the intensity of Si4+ from the HfO2/SiO2/Si(1 0 0) film. With this approximation, the thickness levels of the HfO2 overlayers showed a small standard deviation of 0.03 nm in a series of HfO2 (2 nm)/SiO2 (2-6 nm)/Si(1 0 0) films. Mutual calibration with XPS and transmission electron microscopy (TEM) was used to verify the thickness of HfO2 overlayers in a series of HfO2 (1-4 nm)/SiO2 (3 nm)/Si(1 0 0) films. From the linear relation between the thickness values derived from XPS and TEM, the effective attenuation length of the photoelectrons and the thickness of the HfO2 overlayer could be determined.

Effective attenuation lengths for quantitative determination of surface composition by Auger-electron spectroscopy and X-ray photoelectron spectroscopy

International Nuclear Information System (INIS)

Jablonski, A.; Powell, C.J.

2017-01-01

Highlights: • Effective attenuation lengths (EALs) for determination of surface composition by XPS. • Considerable difference from EALs used for overlayer thickness measurements. • New analytical algorithms for calculating the effective attenuation length. - Abstract: The effective attenuation length (EAL) is normally used in place of the inelastic mean free path (IMFP) to account for elastic-scattering effects when describing the attenuation of Auger electrons and photoelectrons from a planar substrate by an overlayer film. An EAL for quantitative determination of surface composition by Auger-electron spectroscopy (AES) or X-ray photoelectron spectroscopy (XPS) is similarly useful to account for elastic-scattering effects on the signal intensities. We calculated these EALs for four elemental solids (Si, Cu, Ag, and Au) and for energies between 160 eV and 1.4 keV. The XPS calculations were made for two instrumental configurations while the AES calculations were made from the XPS formalism after “switching off” the XPS anisotropy. The EALs for quantitative determination of surface composition by AES and XPS were weak functions of emission angle for emission angles between 0 and 50°. The ratios of the average values of these EALs to the corresponding IMFPs could be fitted to a second-order function of the single-scattering albedo, a convenient measure of the strength of elastic-scattering effects. EALs for quantitative determination of surface composition by AES and XPS for other materials can be simply found from this relationship.

X-ray photoelectron spectroscopy characterization of high dose carbon-implanted steel and titanium alloys

Science.gov (United States)

Viviente, J. L.; García, A.; Alonso, F.; Braceras, I.; Oñate, J. I.

1999-04-01

A study has been made of the depth dependence of the atomic fraction and chemical bonding states of AISI 440C martensitic stainless steel and Ti-6Al-4V alloy implanted with 75 keV C + at very high doses (above 10 18 ions cm -2), by means of X-ray photoelectron spectroscopy combined with an Ar + sputtering. A Gaussian-like carbon distribution was observed on both materials at the lowest implanted dose. More trapezoidal carbon depth-profiles were found with increasing implanted doses, and a pure carbon layer was observed only on the titanium alloy implanted at the highest dose. The implanted carbon was combined with both base metal and carbon itself to form metallic carbides and graphitic carbon. Furthermore, carbon-enriched carbides were also found by curve fitting the C 1s spectra. The titanium alloy showed a higher carbidic contribution than the steel implanted at the same C + doses. A critical carbon concentrations of about 33 at.% and 23 at.% were measured for the formation of C-C bonds in Ti-6Al-4V and steel samples, respectively. The carbon atoms were bound with metal to form carbidic compounds until these critical concentrations were reached; when this C concentration was exceeded the proportion of C-C bonds increased and resulted in the growth of carbonaceous layers.

Determination of carbon in natural freshwater biofilms with total reflection X-ray fluorescence spectrometry

International Nuclear Information System (INIS)

Ovari, M.; Streli, C.; Wobrauschek, P.; Zaray, Gy.

2009-01-01

There is a growing interest in determination of low Z elements, i.e., carbon to phosphorus, in biological samples. Total reflection X-ray fluorescence spectrometry (TXRF) has been already established as suitable trace element analytical method with low sample demand and quite good quantification limits. Recently, the determinable element range was extended towards Z = 6 (carbon). Biofilms can be used for biomonioring purposes in the aquatic environment. Besides the trace metals, especially the determination of the carbon content is important for the better understanding of the early stage of biofilm formation. For this, an ATI low Z spectrometer equipped with Cr-anode X-ray tube, multilayer monochromator, vacuum chamber, and a Si(Li) detector with ultra thin window was used. Biofilms were grown on two different artificial supports (granite and plexiglass), freeze dried, suspended in high purity water and analyzed. As an internal standard the natural titanium content of the biofilms was used. The accuracy of the method was checked by total carbon measurement using a combusting carbon analyzer.

Determination of carbon in natural freshwater biofilms with total reflection X-ray fluorescence spectrometry

Energy Technology Data Exchange (ETDEWEB)

Ovari, M. [Department of Analytical Chemistry, Eoetvoes University, Budapest, H-1117, Budapest, Pazmany Peter stny. 1/a. (Hungary)], E-mail: ovari@chem.elte.hu; Streli, C.; Wobrauschek, P. [Atominstitut of the Austrian Universities, TU-Wien, Stadionallee 2, A-1020, Wien (Austria); Zaray, Gy. [Department of Analytical Chemistry, Eoetvoes University, Budapest, H-1117, Budapest, Pazmany Peter stny. 1/a. (Hungary); Cooperative Research Centre of Environmental Chemistry, Eoetvoes University, Budapest, H-1117, Budapest, Pazmany Peter stny. 1/a. (Hungary)

2009-08-15

There is a growing interest in determination of low Z elements, i.e., carbon to phosphorus, in biological samples. Total reflection X-ray fluorescence spectrometry (TXRF) has been already established as suitable trace element analytical method with low sample demand and quite good quantification limits. Recently, the determinable element range was extended towards Z = 6 (carbon). Biofilms can be used for biomonioring purposes in the aquatic environment. Besides the trace metals, especially the determination of the carbon content is important for the better understanding of the early stage of biofilm formation. For this, an ATI low Z spectrometer equipped with Cr-anode X-ray tube, multilayer monochromator, vacuum chamber, and a Si(Li) detector with ultra thin window was used. Biofilms were grown on two different artificial supports (granite and plexiglass), freeze dried, suspended in high purity water and analyzed. As an internal standard the natural titanium content of the biofilms was used. The accuracy of the method was checked by total carbon measurement using a combusting carbon analyzer.

Chlorine determination in (U, Pu)C fuel by total reflection X-ray fluorescence spectrometry

International Nuclear Information System (INIS)

Misra, Nand Lal; Dhara, Sangita; Mudher, Khush Dev Singh; Aggarwal, Suresh K.; Thakur, Uday Kumar; Shah, Dipti; Sawant, R.M.; Ramakumar, K.L.

2007-01-01

A Total Reflection X-ray Fluorescence (TXRF) method for the determination of chlorine in (U,Pu)C has been developed. The method involves calibration of the instrument with standard solutions and validation of TXRF determination of chlorine using synthetic standard solutions. Cl K α line excited with W L α source was used for TXRF determinations of chlorine. Chlorine present in trace amounts in (U,Pu)C samples was first separated by pyro hydrolysis. The evolved chlorine, in form of HCl, was collected in 5 mM NaOH solution. This solution was analyzed for chlorine by Total Reflection X-ray Fluorescence Spectrometry using cobalt as an internal standard. The TXRF detection limit of chlorine was found to be 3.6 pg with sample size of 30 μL. In order to assess the applicability of TXRF method for chlorine determinations in other nuclear materials, one U 3 O 8 trace element standard was also analyzed for chlorine in similar way. The precision of the method was found to be 25% (1 σ) at ng level in most of the cases. (author)

In situ x-ray photoelectron spectroscopy and capacitance voltage characterization of plasma treatments for Al{sub 2}O{sub 3}/AlGaN/GaN stacks

Energy Technology Data Exchange (ETDEWEB)

Qin, Xiaoye; Lucero, Antonio; Azcatl, Angelica; Kim, Jiyoung; Wallace, Robert M. [Department of Materials Science and Engineering, University of Texas at Dallas, Richardson, Texas 75080 (United States)

2014-07-07

We investigate the Al{sub 2}O{sub 3}/AlGaN/GaN metal-oxide-semiconductor structure pretreated by O{sub 2} anneals, N{sub 2} remote plasma, and forming gas remote plasma prior to atomic layer deposition of Al{sub 2}O{sub 3} using in situ X-ray photoelectron spectroscopy, low energy electron diffraction, and capacitance- voltage measurements. Plasma pretreatments reduce the Ga-oxide/oxynitride formation and the interface state density, while inducing a threshold voltage instability.

X-ray spectrometry and X-ray microtomography techniques for soil and geological samples analysis

International Nuclear Information System (INIS)

Kubala-Kukuś, A.; Banaś, D.; Braziewicz, J.; Dziadowicz, M.; Kopeć, E.; Majewska, U.; Mazurek, M.; Pajek, M.; Sobisz, M.; Stabrawa, I.; Wudarczyk-Moćko, J.; Góźdź, S.

2015-01-01

A particular subject of X-ray fluorescence analysis is its application in studies of the multielemental sample of composition in a wide range of concentrations, samples with different matrices, also inhomogeneous ones and those characterized with different grain size. Typical examples of these kinds of samples are soil or geological samples for which XRF elemental analysis may be difficult due to XRF disturbing effects. In this paper the WDXRF technique was applied in elemental analysis concerning different soil and geological samples (therapeutic mud, floral soil, brown soil, sandy soil, calcium aluminum cement). The sample morphology was analyzed using X-ray microtomography technique. The paper discusses the differences between the composition of samples, the influence of procedures with respect to the preparation of samples as regards their morphology and, finally, a quantitative analysis. The results of the studies were statistically tested (one-way ANOVA and correlation coefficients). For lead concentration determination in samples of sandy soil and cement-like matrix, the WDXRF spectrometer calibration was performed. The elemental analysis of the samples was complemented with knowledge of chemical composition obtained by X-ray powder diffraction.

X-ray spectrometry and X-ray microtomography techniques for soil and geological samples analysis

Energy Technology Data Exchange (ETDEWEB)

Kubala-Kukuś, A.; Banaś, D.; Braziewicz, J. [Institute of Physics, Jan Kochanowski University, ul. Świetokrzyska 15, 25-406 Kielce (Poland); Holycross Cancer Center, ul. Artwińskiego 3, 25-734 Kielce (Poland); Dziadowicz, M.; Kopeć, E. [Institute of Physics, Jan Kochanowski University, ul. Świetokrzyska 15, 25-406 Kielce (Poland); Majewska, U. [Institute of Physics, Jan Kochanowski University, ul. Świetokrzyska 15, 25-406 Kielce (Poland); Holycross Cancer Center, ul. Artwińskiego 3, 25-734 Kielce (Poland); Mazurek, M.; Pajek, M.; Sobisz, M.; Stabrawa, I. [Institute of Physics, Jan Kochanowski University, ul. Świetokrzyska 15, 25-406 Kielce (Poland); Wudarczyk-Moćko, J. [Holycross Cancer Center, ul. Artwińskiego 3, 25-734 Kielce (Poland); Góźdź, S. [Holycross Cancer Center, ul. Artwińskiego 3, 25-734 Kielce (Poland); Institute of Public Health, Jan Kochanowski University, IX Wieków Kielc 19, 25-317 Kielce (Poland)

2015-12-01

A particular subject of X-ray fluorescence analysis is its application in studies of the multielemental sample of composition in a wide range of concentrations, samples with different matrices, also inhomogeneous ones and those characterized with different grain size. Typical examples of these kinds of samples are soil or geological samples for which XRF elemental analysis may be difficult due to XRF disturbing effects. In this paper the WDXRF technique was applied in elemental analysis concerning different soil and geological samples (therapeutic mud, floral soil, brown soil, sandy soil, calcium aluminum cement). The sample morphology was analyzed using X-ray microtomography technique. The paper discusses the differences between the composition of samples, the influence of procedures with respect to the preparation of samples as regards their morphology and, finally, a quantitative analysis. The results of the studies were statistically tested (one-way ANOVA and correlation coefficients). For lead concentration determination in samples of sandy soil and cement-like matrix, the WDXRF spectrometer calibration was performed. The elemental analysis of the samples was complemented with knowledge of chemical composition obtained by X-ray powder diffraction.

Application of X-ray emission techniques for monitoring environmental pollution

International Nuclear Information System (INIS)

Bernasconi, G.; Danesi, P.R.; Dargie, M.; Haselberger, N.; Markowicz, A.; Tajani, A.

1997-01-01

X-ray emission techniques are versatile and powerful methods used for multielement non-destructive analysis. They include X-ray fluorescence (XRF), particle induced X-ray emission (PIXE), scanning electron microscopy combined with X-ray spectrometry and electron probe microanalysis (EPMA). Since many years the IAEA has utilised and promoted these techniques for the analysis of environmental, biological and geological samples. In this paper recent progress at our laboratory in selected aspects related to the application of X-ray emission techniques is briefly overviewed. (authors)

Titanium dioxide nanoparticles: synthesis, X-Ray line analysis and chemical composition study

Energy Technology Data Exchange (ETDEWEB)

Chenari, Hossein Mahmoudi, E-mail: mahmoudi_hossein@guilan.ac.ir, E-mail: h.mahmoudiph@gmail.com [University of Guilan, Rasht (Iran, Islamic Republic of); Seibel, Christoph; Hauschild, Dirk; Reinert, Friedrich [Karlsruhe Institute of Technology - KIT, Gemeinschaftslabor für Nanoanalytik, Karlsruhe (Germany); Abdollahian, Hossein [Nanotechnology Research Center of Urmia University, Urmia, (Iran, Islamic Republic of)

2016-11-15

TiO{sub 2} nanoparticles have been synthesized by the sol-gel method using titanium alkoxide and isopropanol as a precursor. The structural properties and chemical composition of the TiO{sub 2} nanoparticles were studied using X-ray diffraction, scanning electron microscopy, and X-ray photoelectron spectroscopy.The X-ray powder diffraction pattern confirms that the particles are mainly composed of the anatase phase with the preferential orientation along [101] direction. The physical parameters such as strain, stress and energy density were investigated from the Williamson- Hall (W-H) plot assuming a uniform deformation model (UDM), and uniform deformation energy density model (UDEDM). The W-H analysis shows an anisotropic nature of the strain in nano powders. The scanning electron microscopy image shows clear TiO{sub 2} nanoparticles with particle sizes varying from 60 to 80nm. The results of mean particle size of TiO{sub 2} nanoparticles show an inter correlation with the W-H analysis and SEM results. Our X-ray photoelectron spectroscopy spectra show that nearly a complete amount of titanium has reacted to TiO{sub 2}. (author)

Characterization of the electronic structure of C50Cl10 by means of soft x-ray spectroscopies

International Nuclear Information System (INIS)

Brena, Barbara; Luo Yi

2005-01-01

The electronic structure of the last synthesized fullerene molecule, the C 50 Cl 10 , has been characterized by theoretical simulation of x-ray photoelectron spectroscopy, ultraviolet photoelectron spectroscopy, and near-edge x-ray-absorption fine structure. All the calculations were performed at the gradient-corrected and hybrid density-functional theory levels. The combination of these techniques provides detailed information about the valence band and the unoccupied molecular orbitals, as well as about the carbon core orbitals

UV-Raman spectroscopy, X-ray photoelectron spectroscopy, and temperature programmed desorption studies of model and bulk heterogeneous catalysts

Energy Technology Data Exchange (ETDEWEB)

Tewell, Craig Richmond [Univ. of California, Berkeley, CA (United States)

2002-01-01

X-ray photoelectron spectroscopy (XPS) and Temperature Programmed Desorption (TPD) have been used to investigate the surface structure of model heterogeneous catalysts in ultra-high vacuum (UHV). UV-Raman spectroscopy has been used to probe the structure of bulk model catalysts in ambient and reaction conditions. The structural information obtained through UV-Raman spectroscopy has been correlated with both the UHV surface analysis and reaction results. The present day propylene and ethylene polymerization catalysts (Ziegler-Natta catalysts) are prepared by deposition of TiCl₄ and a Al(Et)₃ co-catalyst on a microporous Mg-ethoxide support that is prepared from MgCl₂ and ethanol. A model thin film catalyst is prepared by depositing metallic Mg on a Au foil in a UHV chamber in a background of TiCl₄ in the gas phase. XPS results indicate that the Mg is completely oxidized to MgCl₂ by TiCl₄ resulting in a thin film of MgCl₂/TiCl_x, where x = 2, 3, and 4. To prepare an active catalyst, the thin film of MgCl₂/TiCl_x on Au foil is enclosed in a high pressure cell contained within the UHV chamber and exposed to ~1 Torr of Al(Et)₃.

Determination of C and O and other elements by alpha-induced X-ray energy spectrometry

International Nuclear Information System (INIS)

Henningsen, W.P.; Schaetzler, H.P.; Kuehn, W.

1978-01-01

X-ray energy spectrometry combined with alpha-excitation by means of radionuclides, especially Po-210, has been found as a versatile tool for multielement analysis. Down to Z = 6 (carbon) qualitative and quantitative measurements have been carried out with energy resolution good enough to separate adjacent elements. Thereby errors and lowest detectable concentrations were in the region of one percent. By utilizing M- and L-X-radiation the set of detectable elements can be opened to high atomic numbers. As an example with special regard to environmental research cadmium in organic matrix was measured down to 100 ppm without any preconcentration. Much lower detection limits might be reached by appropriate measures. (orig.) [de

Molecular environment of iodine in naturally iodinated humic substances: Insight from X-ray absorption spectroscopy

International Nuclear Information System (INIS)

Schlegel, Michel L.; Mercier-Bion, Florence; Barre, Nicole; Reiller, Pascal; Moulin, Valerie

2006-01-01

The molecular environment of iodine in reference inorganic and organic compounds, and in dry humic and fulvic acids (HAs and FAs) extracted from subsurface and deep aquifers was probed by iodine L-3-edge X-ray absorption spectroscopy. The X-ray absorption near-edge structure (XANES) of iodine spectra from HAs and FAs resembled those of organic references and displayed structural features consistent with iodine forming covalent bonds with organic molecules. Simulation of XANES spectra by linear combination of reference spectra suggested the predominance of iodine forming covalent bonds to aromatic rings (aromatic-bound iodine). Comparison of extended X-ray absorption fine structure (EXAFS) spectra of reference and samples further showed that iodine was surrounded by carbon shells at distances comparable to those for references containing aromatic-bound iodine. Quantitative analysis of EXAFS spectra indicated that iodine was bound to about one carbon at a distance d(I-C) of 2.01(4)-2.04(9) angstrom, which was comparable to the distances observed for aromatic-bound iodine in references (1.99(1)-2.07(6) angstrom), and significantly shorter than that observed for aliphatic-bound iodine (2.15(2)-2.16(2) angstrom). These results are in agreement with previous conclusions from X-ray photoelectron spectroscopy and from electro-spray ionization mass spectrometry. These results collectively suggest that the aromatic-bound iodine is stable in the various aquifers of this study. (authors)

Study of the electrodeposition of rhenium thin films by electrochemical quartz microbalance and X-ray photoelectron spectroscopy

International Nuclear Information System (INIS)

Schrebler, R.; Cury, P.; Suarez, C.; Munoz, E.; Vera, F.; Cordova, R.; Gomez, H.; Ramos-Barrado, J.R.; Leinen, D.; Dalchiele, E.A.

2005-01-01

Rhenium thin films were prepared by electrodeposition from an aqueous solution containing 0.1 M Na 2 SO 4 +H 2 SO 4 , pH 2 in presence of y mM HReO 4 . As substrates polycrystalline gold (y=0.75 mM HReO 4 ) and monocrystalline n-Si(100) (y=40 mM HReO 4 ) were used. The electrochemical growth of rhenium was studied by cyclic voltammetry and electrochemical quartz microbalance on gold electrodes. The results found in the potential region before the hydrogen evolution reaction (her) showed that ReO 3 , ReO 2 and Re 2 O 3 with different hydration grades can be formed. In the potential region where the her is occurring, either on gold or n-Si(100) the electrodeposition of metallic rhenium takes place. On both substrates, rhenium films were formed by electrolysis at constant potential and X-ray photoelectron spectroscopy technique was used to characterise these deposits. It was concluded that the electrodeposited films were of metallic rhenium and only the uppermost atomic layer contained rhenium oxide species

An XPS [x-ray photoelectron spectroscopy] study of the sulfidation-regeneration cycle of a hydroprocessing catalyst

Energy Technology Data Exchange (ETDEWEB)

Shang, D.Y.; Adnot, A.; Kaliaguine, S. (Laval Univ., Ste-Foy, PQ (Canada)); Chmielowiec, J. (Petro Canada Products Co., Mississauga, ON (Canada))

1993-10-01

The formation of sulfates in an industrial Ni-W hydroprocessing (HP) catalyst was investigated by x-ray photoelectron spectroscopy (XPS). A small fluidized bed test unit with on-line sampling device was constructed to simulate industrial sulfidation and oxyregeneration processes of HP catalysts. The results obtained show that the sulfates observed on the surface of sulfided catalysts are not formed during the sulfidation process. Two oxidation processes seem to be responsible for the formation of sulfates: one happens when the catalyst is exposed to air before it is properly cooled and the other is a slow conversion at ambient temperature. The two different processes might be associated to different sulfidic species formed during the sulfidation processes, with the sulfides in the bulk of catalyst particles being more easily oxidized than the ones on the external surface of the catalyst particles. The sulfate formed during the air oxidation of sulfided catalysts, as well as that after oxyregeneration, is not aluminum sulfate but nickel sulfate in both cases. XPS results also indicate that oxygenates in the feedstock are not directly involved in the sulfate formation. 18 refs., 9 figs., 6 tabs.

Ion bombardment and adsorption studies on ilmenite (FeTiO3) by X-ray photoelectron spectroscopy

International Nuclear Information System (INIS)

Schulze, P.D.

1983-01-01

The effects of 5 KeV argon and oxygen ion bombardment on FeTiO3 (ilmenite) at low temperatures have been studied using x-ray photoelectron spectroscopy (XPS). Also, using this same technique, the adsorption of O 2 , NO, N 2 O, and CO at 300 K and the adsorption of O 2 and D 2 O at 150K have been studied. Argon and oxygen ion bombardment of ilmenite have confirmed earlier studies on metal oxides that argon ions generally reduce the anion species while oxygen ions generally oxidize the anion species. The two iron states involved were Fe sup +2 and Fe sup O. The reduction of Ti sup +4 was not verified although a significant shift in the Ti(2p1,3) binding energies toward the metallic state was observed after oxygen ion bombardment at low temperatures. At temperatures above 150K, O 2 adsorbs dissociatively on ilmenite while D 2 O adsorbs molecularly below 170K. Above 300 K NO, N 2 O, and CO do not appear to adsorb dissociatively. Low temperature adsorption of D 2 O was found to be inhibited by predosing the ilmenite with O 2

Ion bombardment and adsorption studies on ilmenite (FeTiO3) by X-ray photoelectron spectroscopy

Science.gov (United States)

Schulze, P. D.

1983-01-01

The effects of 5 KeV argon and oxygen ion bombardment on FeTiO3 (ilmenite) at low temperatures have been studied using X-ray photoelectron spectroscopy (XPS). Also, using this same technique, the adsorption of O2, NO, N2O, and CO at 300 K and the adsorption of O2 and D2O at 150K have been studied. Argon and oxygen ion bombardment of ilmenite have confirmed earlier studies on metal oxides that argon ions generally reduce the anion species while oxygen ions generally oxidize the anion species. The two iron states involved were Fe sup +2 and Fe sup O. The reduction of Ti sup +4 was not verified although a significant shift in the Ti(2p1,3) binding energies toward the metallic state was observed after oxygen ion bombardment at low temperatures. At temperatures above 150K, O2 adsorbs dissociatively on ilmenite while D2O adsorbs molecularly below 170K. Above 300 K No, N2O, and CO do not appear to adsorb dissociatively. Low temperature adsorption of D2O was found to be inhibited by predosing the ilmenite with O2.

Analysis for iodide in groundwater by x-ray fluorescence spectrometry after collection as silver iodide on activated charcoal

International Nuclear Information System (INIS)

Howe, P.T.

1980-01-01

The report describes the determination of microgram quantities of iodide in water by X-ray fluorescence spectrometry. The iodide is concentrated by precipitation as silver iodide on activated charcoal. If a 60-mL sample is available, a concentration of 0.12 mg/L can be detected. Precision (2σ) at the 1-mg/L level is +- 0.08 mg/L. (auth)

Investigation of the interaction of Greek dolomitic marble with metal aqueous solutions using Rutherford backscattering and X-ray photoelectron spectroscopy

International Nuclear Information System (INIS)

Godelitsas, A.; Kokkoris, M.; Misaelides, P.

2005-01-01

The interaction of dolomitic marble from Thassos Island (northern Aegean sea, Greece) with Co 2+ -, Cd 2+ -, Pb 2+ - and Cr 3+ - aqueous solutions (metal concentration: 1000 mgL -1 ) was investigated using Rutherford backscattering (RBS) and X-ray photoelectron spectroscopy (XPS). The initial material as well as the interaction products were also characterized by scanning electron microscopy (SEM/EDS), radioisotope induced X-ray fluorescence analysis (RI-XRFA), powder X-ray diffraction (Powder-XRD) and Fourier transform infra-red spectroscopy (FT-IR). The contact time of the samples with the aqueous solutions was one week and took place under ambient temperature. To our knowledge, the sorption of the above mentioned metals with dolomite (CaMg(CO 3 ) 2 ) has not yet been presented in the literature and the only data available concern the adsorption of Ca, Mg and Nd from NaCl solutions. The Thassos island dolomitic marble is a snow-white homogeneous carbonate metamorphic rock, with fine physicochemical and mechanical properties, currently used as natural building stone in many parts of the world (see http://www.thassosmarble.com), This dolomite-bearing material was also extensively used in the past as construction material of many .classical Greek and Roman sculptures and architectural elements; in 301 AD the Roman emperor Diocletian included 'Thassian marble' in the list of the 19 most expensive and important 'marbles' produced in the imperial quarries. Previous literature presented the isotopic analysis(δ 13 C, δ 18 O) and EPR studies (Mn 2+ and Fe 3+ ) of this stone. The obtained results indicated a limited Cd 2+ - and Co 2+ -sorption on the dissolved surface of the carbonate substrate, whereas, under the same experimental conditions, the Pb 2+ - and Cr 3+ -interaction is more intense leading to extended overgrowth of crystalline Pb-carbonates and surface precipitation of amorphous Cr-hydroxides/oxyhydroxides.

Gas pixel detector for X-ray observation

CERN Document Server

Attié, D; Chefdeville, M; Colas, P; Delagnes, E; Giomataris, Y; van der Graaf, H; Llopart, X; Timmermans, J; Visschers, J

2009-01-01

We report on the status of the R&D for a digital Time Projection Chamber (TPC) based on Micromegas (MICRO MEsh GAseous Structure) detectors using the CMOS chip TimePix as a direct readout anode protected by highly resistive a-Si:H layer. A small chamber was built as a demonstrator of the 2-D and 3-D imaging capabilities of this technique. We illustrate the new capabilities of this detector for X-ray observation with data taken from radioactive sources. This small TPC is a very useful tool both for studying gas properties thanks to its good efficiency for single electrons, and for reconstructing photoelectron direction for use as a soft X-ray polarimeter.

The analysis, by a fusion procedure and X-ray-fluorescence spectrometry, of silicates and slags

International Nuclear Information System (INIS)

Jacobs, J.J.; Balaes, A.M.E.

1980-01-01

A glass-disc fusion method is described for the analysis, by X-ray-fluorescence spectrometry, of slags and silicate materials. The data are corrected for detector dead time and short-term instrumental drift. Corrections are made for matrix variations by use of the Lachange-Traill mathematical model, and the results are processed on a mini-computer, an iterative procedure being used in the solving of the simultaneous equations. As the alpha-correction coefficients of the Lachange-Traill model are not truly constant, a modified version of the model is proposed [af

Enhanced Adsorption of p-Arsanilic Acid from Water by Amine-Modified UiO-67 as Examined Using Extended X-ray Absorption Fine Structure, X-ray Photoelectron Spectroscopy, and Density Functional Theory Calculations.

Science.gov (United States)

Tian, Chen; Zhao, Jian; Ou, Xinwen; Wan, Jieting; Cai, Yuepeng; Lin, Zhang; Dang, Zhi; Xing, Baoshan

2018-03-20

p-Arsanilic acid ( p-ASA) is an emerging organoarsenic pollutant comprising both inorganic and organic moieties. For the efficient removal of p-ASA, adsorbents with high adsorption affinity are urgently needed. Herein, amine-modified UiO-67 (UiO-67-NH 2 ) metal-organic frameworks (MOFs) were synthesized, and their adsorption affinities toward p-ASA were 2 times higher than that of the pristine UiO-67. Extended X-ray absorption fine structure (EXAFS), X-ray photoelectron spectroscopy (XPS), and density functional theory (DFT) calculation results revealed adsorption through a combination of As-O-Zr coordination, hydrogen bonding, and π-π stacking, among which As-O-Zr coordination was the dominant force. Amine groups played a significant role in enhancing the adsorption affinity through strengthening the As-O-Zr coordination and π-π stacking, as well as forming new adsorption sites via hydrogen bonding. UiO-67-NH 2 s could remove p-ASA at low concentrations (<5 mg L -1 ) in simulated natural and wastewaters to an arsenic level lower than that of the drinking water standard of World Health Organization (WHO) and the surface water standard of China, respectively. This work provided an emerging and promising method to increase the adsorption affinity of MOFs toward pollutants containing both organic and inorganic moieties, via modifying functional groups based on the pollutant structure to achieve synergistic adsorption effect.

Understanding the Oxygen Evolution Reaction Mechanism on CoOx using Operando Ambient-Pressure X-ray Photoelectron Spectroscopy

International Nuclear Information System (INIS)

Favaro, Marco; Yang, Jinhui; Nappini, Silvia; Magnano, Elena

2017-01-01

Photoelectrochemical water splitting is a promising approach for renewable production of hydrogen from solar energy and requires interfacing advanced water-splitting catalysts with semiconductors. Understanding the mechanism of function of such electrocatalysts at the atomic scale and under realistic working conditions is a challenging, yet important, task for advancing efficient and stable function. This is particularly true for the case of oxygen evolution catalysts and, here, we study a highly active Co 3 O 4 /Co(OH) 2 biphasic electrocatalyst on Si by means of operando ambient-pressure X-ray photoelectron spectroscopy performed at the solid/liquid electrified interface. Spectral simulation and multiplet fitting reveal that the catalyst undergoes chemical-structural transformations as a function of the applied anodic potential, with complete conversion of the Co(OH) 2 and partial conversion of the spinel Co 3 O 4 phases to CoO(OH) under precatalytic electrochemical conditions. Furthermore, we observe new spectral features in both Co 2p and O 1s core-level regions to emerge under oxygen evolution reaction conditions on CoO(OH). The operando photoelectron spectra support assignment of these newly observed features to highly active Co 4+ centers under catalytic conditions. Comparison of these results to those from a pure phase spinel Co 3 O 4 catalyst supports this interpretation and reveals that the presence of Co(OH) 2 enhances catalytic activity by promoting transformations to CoO(OH). The direct investigation of electrified interfaces presented in this work can be extended to different materials under realistic catalytic conditions, thereby providing a powerful tool for mechanism discovery and an enabling capability for catalyst design.

X-ray dosimetry in mammography for W/Mo and Mo/Mo combinations utilizing Compton spectrometry

International Nuclear Information System (INIS)

Almeida Junior, Jose N.; Terini, Ricardo A.; Herdade, Silvio B.; Furquim, Tania A.C.

2009-01-01

Mean Glandular Dose (MGD) cannot be measured directly in mammography equipment. Therefore, methods based on Compton spectrometry are alternatives to evaluate dose distributions in a standard breast phantom, as well as mean glandular dose. In this work, a CdTe detector was used for the spectrometry measurements of radiation scattered by compton effect, at nearly 90, by a PMMA cylinder. For this, the reconstruction of primary beam spectra from the scattered ones has been made using Klein-Nishina theory and Compton formalism, followed by a determination of incident air kerma, absorbed dose values in the breast phantom and, finally, MGD. Incident and attenuated X-ray spectra and depth-dose distributions in a BR-12 phantom have been determined and are presented for the mammography range (28 to 35kV), showing good agreement with previous literature data, obtained with TLD. (author)

Photoelectron studies of machined brass surfaces

Science.gov (United States)

Potts, A. W.; Merrison, J. P.; Tournas, A. D.; Yacoot, A.

UV photoelectron spectroscopy has been used to determine the surface composition of machined brass. The results show a considerable change between the photoelectron surface composition and the bulk composition of the same sample determined by energy-dispersive X-ray fluorescence. On the surface the lead composition is increased by ˜900 G. This is consistent with the important part that lead is believed to play in improving the machinability of this alloy.

Simple procedure for nutrient analysis of coffee plant with energy dispersive X-ray fluorescence spectrometry (EDXRF)

Energy Technology Data Exchange (ETDEWEB)

Tezotto, Tiago; Favarin, Jose Laercio; Neto, Ana Paula; Azevedo, Ricardo Antunes, E-mail: tiago.tezotto@usp.br [Escola Superior de Agricultura Luiz de Queiroz (ESALQ/USP), Piracicaba, SP (Brazil); Gratao, Priscila Lupino [Universidade Estadual Paulista Julio de Mesquita Filho (UNESP/ FCAV), Jaboticabal, SP (Brazil). Dept. de Biologia Aplicada a Agropecuaria; Mazzafera, Paulo [Universidade Estadual de Campinas (UNICAMP/IB), SP (Brazil). Dept. Biologia Vegetal

2013-07-15

Nutrient analysis is used to estimate nutrient content of crop plants to manage fertilizer application for sustained crop production. Direct solid analysis of agricultural and environmental samples by energy dispersive X-ray fluorescence spectrometry (EDXRF) was chosen as alternative technique to evaluate the simultaneous multielemental quantification of the most important essential elements in coffee (Coffea arabica L.) plants. Inductively coupled plasma atomic emission spectrometry and certified reference materials made from leaves were used to calibrate and check the trueness of EDXRF method for the determination of the concentration of several nutrients in coffee leaves and branches. Fluorescence spectrometry proved to be advantageous and presented low cost as loose powder samples could be used. Samples collected from a field experiment where coffee plants were treated with excess of Ni and Zn were used to verify the practical application of the method. Good relationships were achieved between certified values and data obtained by EDXRF, with recoveries ranging from 82 to 117 %.(author)

Determination of impurities in magnesium and aluminium by X-ray fluorescence spectrometry

International Nuclear Information System (INIS)

Roca, M.; Diaz-Guerra, J.P.

1979-01-01

The determination of traces of Al, Cr, Cu, Fe, Mn, Ni, Pb, Si and of Bi, Cr, Cu, Fe, Ga, Mg, Mn, Ni, Pb, Si, Sn, Ti, V and Zn in samples of magnesium and aluminium, respectively, by means of X-ray fluorescence spectrometry, are studied. An automatic sequential spectrometer with an on-line computer for the treatment of data has been employed. The most suitable measurement parameters have been chosen for each element in order to achieve detection limits to a few p.p.m. For magnesium in the form of drillings the analyses are performed with satisfactory results for most impurities by pressing the samples into briquettes and employing metallic discs as standards. Correction methods for the spectral interferences of Ti on V, and V on Cr have been applied. (author)

Electronic properties and bonding in Zr Hx thin films investigated by valence-band x-ray photoelectron spectroscopy

Science.gov (United States)

Magnuson, Martin; Schmidt, Susann; Hultman, Lars; Högberg, Hans

2017-11-01

The electronic structure and chemical bonding in reactively magnetron sputtered Zr Hx (x =0.15 , 0.30, 1.16) thin films with oxygen content as low as 0.2 at.% are investigated by 4d valence band, shallow 4p core-level, and 3d core-level x-ray photoelectron spectroscopy. With increasing hydrogen content, we observe significant reduction of the 4d valence states close to the Fermi level as a result of redistribution of intensity toward the H 1s-Zr 4d hybridization region at ˜6 eV below the Fermi level. For low hydrogen content (x =0.15 , 0.30), the films consist of a superposition of hexagonal closest-packed metal (α phase) and understoichiometric δ -Zr Hx (Ca F2 -type structure) phases, while for x =1.16 , the films form single-phase Zr Hx that largely resembles that of stoichiometric δ -Zr H2 phase. We show that the cubic δ -Zr Hx phase is metastable as thin film up to x =1.16 , while for higher H contents the structure is predicted to be tetragonally distorted. For the investigated Zr H1.16 film, we find chemical shifts of 0.68 and 0.51 eV toward higher binding energies for the Zr 4 p3 /2 and 3 d5 /2 peak positions, respectively. Compared to the Zr metal binding energies of 27.26 and 178.87 eV, this signifies a charge transfer from Zr to H atoms. The change in the electronic structure, spectral line shapes, and chemical shifts as a function of hydrogen content is discussed in relation to the charge transfer from Zr to H that affects the conductivity by charge redistribution in the valence band.

Photoelectron diffraction k-space volumes of the c(2x2) Mn/Ni(100) structure

Energy Technology Data Exchange (ETDEWEB)

Banerjee, S.; Denlinger, J.; Chen, X. [Univ. of Wisconsin, Milwaukee, WI (United States)] [and others

1997-04-01

Traditionally, x-ray photoelectron diffraction (XPD) studies have either been done by scanning the diffraction angle for fixed kinetic energy (ADPD), or scanning the kinetic energy at fixed exit angle (EDPD). Both of these methods collect subsets of the full diffraction pattern, or volume, which is the intensity of photoemission as a function of momentum direction and magnitude. With the high density available at the Spectromicroscopy Facility (BL 7.0) {open_quotes}ultraESCA{close_quotes} station, the authors are able to completely characterize the photoelectron diffraction patterns of surface structures, up to several hundred electron volts kinetic energy. This large diffraction `volume` can then be analyzed in many ways. The k-space volume contains as a subset the energy dependent photoelectron diffraction spectra along all emission angles. It also contains individual, hemispherical, diffraction patterns at specific kinetic energies. Other `cuts` through the data set are also possible, revealing new ways of viewing photoelectron diffraction data, and potentially new information about the surface structure being studied. In this article the authors report a brief summary of a structural study being done on the c(2x2) Mn/Ni(100) surface alloy. This system is interesting for both structural and magnetic reasons. Magnetically, the Mn/Ni(100) surface alloy exhibits parallel coupling of the Mn and Ni moments, which is opposite to the reported coupling for the bulk, disordered, alloy. Structurally, the Mn atoms are believed to lie well above the surface plane.

The Determination of Composite Elements in Zircaloy-2 by X-Ray Fluorescence and Emission Spectrometry Method

International Nuclear Information System (INIS)

Dian Anggraini; Rosika Kriswarini; Yusuf N

2007-01-01

Analysis of composing elements in zircaloy-2 has been done by Emission Spectrometry method and X-Ray Fluorescence (XRF). The aim of the analysis is to verify conformity between composing elements in zircaloy-2 and the material certificate. Spectrometry Emission method has higher sensitivity in element determination of a material than that of XRF method, so can be estimated that emission spectrometry method has higher accuracy than that of XRF method. The result of qualitative analysis by Emission Spectrometry indicate that the composing elements in zircaloy-2 were Sn, Cr and Ni. However, the qualitative analysis result by XRF method indicated that the composing elements in zircaloy 2 were Sn, Cr, Ni and Fe. Fe element can not be analysed by Emission Spectrometry method because Emission Spectrometer did not equipped with Fe detector. The quantitative analysis result of the composing elements in the material with both methods showed that Sn, Cr and Ni concentration of zircaloy 2 existed in concentration ranges of the material certificate. Result of statistical test (F and t-test) of analysis result of both methods can be used for analyzing composing elements in zircaloy 2. Emission Spectrometry method was more sensitive and accurate for determining Cr and Ni element in zircaloy 2 than that of emission Spectrometry method but both methods had same accuracy. The precision of measurement of Sn, Cr and Ni element using XRF method was better than that of Emission spectrometry method. (author)

The possible effect of solar soft X rays on thermospheric nitric oxide

International Nuclear Information System (INIS)

Siskind, D.E.; Barth, C.A.; Cleary, D.D.

1990-01-01

A rocket measurement of thermospheric nitric oxide (NO) is used to evaluate the production of odd nitrogen by solar soft X rays (18-50 angstrom). The rocket observation was performed over White Sands Missile Range on November 9, 1981, at 1500 LT for solar maximum conditions (F10.7 = 233). The peak observed NO density was 6.3 x 10 7 cm -3 at 102 km. A photochemical model which included soft X rays was used for comparison with the data. The soft X rays create photoelectrons which lead to enhanced ionization of N 2 and thus increased odd nitrogen production. A good fit to the data was achieved using a soft X ray flux of 0.75 erg cm -2 s -1

Comparison of X-ray photoelectron spectroscopy multiplet splitting of Cr 2p peaks from chromium tris(β-diketonates) with chemical effects

Energy Technology Data Exchange (ETDEWEB)

Liu, R.; Conradie, J.; Erasmus, E., E-mail: erasmuse@ufs.ac.za

2016-01-15

Graphical abstract: Synopsis and pictogram for Table of contents The Cr 2p{sub 3/2} peaks obtained from X-ray photoelectron spectra (XPS) of a series of chromium(III) β-diketonato complexes were fitted with calculated multiplet peaks. The ratio of the fac and mer isomers obtained from XPS compared very well with the Boltzmann calculated ratio. The electronegativity of the R-groups on the β-diketonato ligand influences the XPS peak positions. - Highlights: • β-diketonato complexes Cr(RCOCHCOR’){sub 3} • Cr 2p{sub 3/2} XPS peaks fitted with calculated multiplet peaks. • Different calculated multiplet peaks fit the Cr 2p{sub 3/2} peak for fac and mer isomers. • XPS peak positions influenced by the electronegativity of the R- and R'-group. - Abstract: X-ray photoelectron spectra (XPS) measurements of a series of chromium(III) β-diketonato complexes of the Cr 2p spectra was fitted with calculated multiplet peaks. The XPS of these Cr(III) complexes did not exhibit fine structure, however, well-defined line shapes could be fitted to the Cr 2p{sub 3/2} envelope. The splitting patterns obtained for the Cr(III) β-diketonato complexes compared well with the multiplet splitting predicted by Gupta and Sen for the free Cr(III) ion. The Cr(III) β-diketonato complexes containing unsymmetrically substituted β-diketonato ligands, which display both the fac and mer isomers, could be fitted with two sets of multiplets and were useful in determining the ratio between the fac and mer isomers, which was compared with the Boltzman calculated ratio obtained from density functional theory energies. The obtained binding energy of the first multiplet splitting peak of the Cr 2p{sub 3/2} envelope was found to be dependent on the combined Gordy group electronegativity of the R-groups substituted on the β-diketonato ligand (RCOCHCOR′){sup −}.

Improvements on Low Level Activity Gamma Measurements and X-ray Spectrometry at the CEA-MADERE Measurement Platform

OpenAIRE

Sergeyeva Victoria; Domergue Christophe; Destouches Christophe; Girard Jean Michel; Philibert Hervé; Bonora Jonathan; Thiollay Nicolas; Lyoussi Abdallah

2016-01-01

The CEA MADERE platform (Measurement Applied to DosimEtry in REactors) is a part of the Instrumentation Sensors and Dosimetry Laboratory (LDCI). This facility is dedicated to the specific activity measurements of solid and radioactive samples using Gamma and X-ray spectrometry. MADERE is a high-performance facility devoted to neutron dosimetry for experimental programs performed in CEA and for the irradiation surveillance programmes of PWR vessels. The MADERE platform is engaged in a continuo...

The analysis of anode sludges by x-ray-fluorescence spectrometry

International Nuclear Information System (INIS)

Austen, C.E.; Wall, G.J.

1978-01-01

A method is described for the analysis, by X-ray-fluorescence spectrometry, of anode sludges for the determination of antimony, bismuth, copper, iron, lead, nickel, selenium, silver, tellurium, tin, and zinc. The preparation of the samples involves fusion with a flux of barium peroxide and lithium hydroxide, and with dichromium trioxide as the internal standard, in a zirconium or vitreous-carbon crucible and casting of the melt in an aluminium mould; the fused disc so formed is then pulverized and briquetted to form pellets. Calibration curves, which are straight lines for all the elemets determined because the flux contains a heavy absorber, are established by measurement of pellets prepared from standard anode sludges, pure metals, compounds of the metals, or any combination of these materials. The precision of the results varies between 2 and 15 per cent relative standard deviation, depending on the concentration of the element being determined. The accuracy of the results is comparable with that obtained by wet-chemical methods. The laboratory method is given in an appendix

X-ray photoelectron spectroscopy/Ar+ ion profile study of thin oxide layers on InP

International Nuclear Information System (INIS)

Thurgate, S.M.; Erickson, N.E.

1990-01-01

The effect of incremental ion bombardment on the surface layers of an aqua regia etched InP sample was studied by monitoring the components of the In 3d 5/2 and O 1s x-ray photoelectron spectroscopy (XPS) lines as the sample was bombarded with low energy (1 keV) Ar + ions. The changes in the stoichiometry of the surface produced large shifts in the position of the In 3d and O 1s lines that were not paralleled by shifts in the P 2p line. Analysis of these shifts indicated that the surface was covered with a mixture of indium hydroxide and indium phosphate, with the phosphate closer to the InP substrate. It is proposed that this layer structure is due to differences in the dissolution rates of the oxidation products in the acid etch and the effect of the distilled water rinse. It may be possible to alter the composition of such oxides by carefully tailoring the etch conditions to optimize the kinetics for the particular oxide phase required. The analysis of the XPS lines also showed that the InP substrate was damaged at very low ion doses, and finally decomposed by the ion beam. When the ion ''cleaned'' sample was exposed to oxygen, a different oxide system was produced which consisted largely of In 2 O 3 and InPO 4 [or In(PO 3 ) x ]. This model of the oxidized surface of InP is consistent with other measurements and we conclude that ion milling together with XPS and careful curve fitting can be used to find the nature of the thin oxides on InP

Band alignment study of lattice-matched In{sub 0.49}Ga{sub 0.51}P and Ge using x-ray photoelectron spectroscopy

Energy Technology Data Exchange (ETDEWEB)

Owen, Man Hon Samuel, E-mail: m.owen.sg@ieee.org, E-mail: yeo@ieee.org; Zhou, Qian; Gong, Xiao; Yeo, Yee-Chia, E-mail: m.owen.sg@ieee.org, E-mail: yeo@ieee.org [Department of Electrical and Computer Engineering, National University of Singapore, Singapore 119260 (Singapore); Zhang, Zheng; Pan, Ji Sheng [Institute of Materials Research and Engineering, A*STAR (Agency for Science, Technology and Research), 3 Research Link, Singapore 117602 (Singapore); Loke, Wan Khai; Wicaksono, Satrio; Yoon, Soon Fatt [School of Electrical and Electronic Engineering, Nanyang Technological University (NTU), Nanyang Avenue, Singapore 639798 (Singapore); Tok, Eng Soon [Department of Physics, National University of Singapore, Singapore 117551 (Singapore)

2014-09-08

Lattice-matched In{sub 0.49}Ga{sub 0.51}P was grown on a p-type Ge(100) substrate with a 10° off-cut towards the (111) by low temperature molecular beam epitaxy, and the band-alignment of In{sub 0.49}Ga{sub 0.51}P on Ge substrate was obtained by high resolution x-ray photoelectron spectroscopy. The valence band offset for the InGaP/Ge(100) interface was found to be 0.64 ± 0.12 eV, with a corresponding conduction band offset of 0.60 ± 0.12 eV. The InGaP/Ge interface is found to be of the type I band alignment.

Nonlocal heat transport and improved target design for x-ray heating studies at x-ray free electron lasers

Science.gov (United States)

Hoidn, Oliver; Seidler, Gerald T.

2018-01-01

The extremely high-power densities and short durations of single pulses of x-ray free electron lasers (XFELs) have opened new opportunities in atomic physics, where complex excitation-relaxation chains allow for high ionization states in atomic and molecular systems, and in dense plasma physics, where XFEL heating of solid-density targets can create unique dense states of matter having temperatures on the order of the Fermi energy. We focus here on the latter phenomena, with special emphasis on the problem of optimum target design to achieve high x-ray heating into the warm dense matter (WDM) state. We report fully three-dimensional simulations of the incident x-ray pulse and the resulting multielectron relaxation cascade to model the spatial energy density deposition in multicomponent targets, with particular focus on the effects of nonlocal heat transport due to the motion of high energy photoelectrons and Auger electrons. We find that nanoscale high-Z /low-Z multicomponent targets can give much improved energy density deposition in lower-Z materials, with enhancements reaching a factor of 100. This has three important benefits. First, it greatly enlarges the thermodynamic parameter space in XFEL x-ray heating studies of lower-Z materials. Second, it allows the use of higher probe photon energies, enabling higher-information content x-ray diffraction (XRD) measurements such as in two-color XFEL operations. Third, while this is merely one step toward optimization of x-ray heating target design, the demonstration of the importance of nonlocal heat transport establishes important common ground between XFEL-based x-ray heating studies and more traditional laser plasma methods.

A quantitative study of valence electron transfer in the skutterudite compound CoP3 by combining x-ray induced Auger and photoelectron spectroscopy

International Nuclear Information System (INIS)

Diplas, S; Prytz, Oe; Karlsen, O B; Watts, J F; Taftoe, J

2007-01-01

We use the sum of the ionization and Auger energy, the so-called Auger parameter, measured from the x-ray photoelectron spectrum, to study the valence electron distribution in the skutterudite CoP 3 . The electron transfer between Co and P was estimated using models relating changes in Auger parameter values to charge transfer. It was found that each P atom gains 0.24 e - , and considering the unit formula CoP 3 this is equivalent to a donation of 0.72 e - per Co atom. This is in agreement with a recent electron energy-loss spectroscopy study, which indicates a charge transfer of 0.77 e - /atom from Co to P

Ultrathin copper aluminum and nickel aluminide protective oxidation studied with an x-ray photoelectron spectrometer

Science.gov (United States)

Moore, J. F.; McCann, M. P.; Pellin, M. J.; Zinovev, A.; Hryn, J. N.

2003-09-01

Oxidation in a regime where diffusion is rapid and pressures are low is addressed. Kinetic effects under these conditions are minimized and a protective oxide film of near-equilibrium composition that is a few nanometers thick may form. Ultrathin oxides have great potential for addressing the corrosion resistance of metals, since they do not always suffer stress-induced cracking upon thermal cycling, and can be reformed under high temperature, oxidizing environments. Ultrathin oxide films are also preferable to those on a thick oxide scale for electrochemical applications due to their electrical properties. To study the growth of these oxide films, we have developed a high signal x-ray photoelectron spectrometer. The instrument can measure the near-surface composition during growth under oxygen partial pressures of up to 10-5 mbar and surface temperatures up to 1300 K. Under these conditions, films grow to a level of 3 nm in 1 h. Experiments with Cu-Al alloys show rapid segregation of Al upon oxygen exposure at 875 K, whereas exposures at lower temperatures result in a mixed oxide. With a Ni-Al intermetallic, higher temperatures were needed to preferentially segregate Al. Thermal cycling followed by exposure to chlorine in the same instrument is used as a measure of the degree of corrosion resistance of the oxides in question.

Determination of rubidium and strontium in geological materials by X-Ray fluorescence spectrometry

International Nuclear Information System (INIS)

Roca, M.

1979-01-01

In order to determine whole-rock ages by the Rb/Sr procedure, an X-ray fluorescence spectrometry method for the determination of both elements has been developed. The samples are pressed into boric acid backed and ringed pellets with this material as a binding agent. Matrix corrections are made following the determination od the mass absorption coefficients, based on the intensity of the Compton-scattered peak of MoKα. or MoKβ 1 .3. The U. S. Geological Survey granodiorite GSP-1 is used as a reference standard. Spectral-line interferences have been carefully studied and the empirical correction factors determined. A BASIC language program for calculating the Rb and Sr concentrations and the Rb/Sr ratios has been written. (Author) 7 refs

Contribution of photoelectron spectrometry and infrared spectrometry to the study of various oxidised forms of chromium

International Nuclear Information System (INIS)

Feve, L.

1985-03-01

Securate knowledge of internal surface of primary coolant circuits of PWR is required for an estimation of dissolution of used materials and for estimation of decontamination efficiency. The binding energies of various electron levels of chromium were determined by photoelectron spectrometry (ESCA), both for the metal and for certain compounds. Because of the intensities of the signals obtained the 2 p 3/2 level alone can be used for analytical purposes. Owing to a possible interference between this level due to hexavalent chromium and a satellite peak caused by trivalent chromium the method is not able to show up small amounts of chromium VI in chromium III. Simultaneous detection of the hexavalent and trivalent forms was achieved by infrared spectrometry. The problem of revealing traces of chromium VI in surface layers of trivalent chromium oxide has thus been solved [fr

Photoelectron spectroscopic studies of some transition metals and alloys

International Nuclear Information System (INIS)

McLachlan, A.D.

1974-01-01

Photoelectron spectra of polycrystalline samples of Cu, Ag and Au at photon energies of 21.22, 40.81 eV and 1487 eV were measured. The corrected 40.81 eV results were compared to theoretical band structure calculations and monochromatized x-ray photoelectron results. Correlation of hitherto unresolved peaks in the 40.81 eV spectra was observed. Comparison of the relative intensities of the spectral d bands and the theoretical calculations revealed discrepancies which were assigned to matrix element modulation effects in the photoelectron emission process. Experimental measurements and theories of the electronic structure of disordered alloy systems were reviewed. The 21.22 eV and 40.81 eV photoelectron spectra of some AgPd and AgAu alloys were measured. The spectra were compared with previous x-ray photon results, and with theoretical calculations based on the Coherent Potential Approximation (CPA) model of disordered alloy systems. The present results were found to give more clearly defined spectral details, with differences in the comparison reflecting the simplifying assumptions of the CPA calculation. (author)

Determination of zinc in ammoniacal ore leaching solutions by X-ray fluorescence spectrometry using a radioactive source

International Nuclear Information System (INIS)

Cornejo, N.; Afailal, A.; Garcia, F.; Palacios, M.

1994-01-01

A method was developed for the fast determination of zinc in leaching solutions by radioisotope energy-dispersive X-ray fluorescence (EDXRF) spectrometry. The measured intensities were used to develop regression models for estimating the zinc concentration. The primary radiation was provided by the 244 Cm radioisotope. Several experimental parameters including the saturation thickness and detection limit were determined. The advantages of the utilization of conditioning agents with elements of low atomic number such as nitric acid were established. (orig.)

Effect of Cl2- and HBr-based inductively coupled plasma etching on InP surface composition analyzed using in situ x-ray photoelectron spectroscopy

International Nuclear Information System (INIS)

Bouchoule, S.; Vallier, L.; Patriarche, G.; Chevolleau, T.; Cardinaud, C.

2012-01-01

A Cl 2 -HBr-O 2 /Ar inductively coupled plasma (ICP) etching process has been adapted for the processing of InP-based heterostructures in a 300-mm diameter CMOS etching tool. Smooth and anisotropic InP etching is obtained at moderate etch rate (∼600 nm/min). Ex situ x-ray energy dispersive analysis of the etched sidewalls shows that the etching anisotropy is obtained through a SiO x passivation mechanism. The stoichiometry of the etched surface is analyzed in situ using angle-resolved x-ray photoelectron spectroscopy. It is observed that Cl 2 -based ICP etching results in a significantly P-rich surface. The phosphorous layer identified on the top surface is estimated to be ∼1-1.3-nm thick. On the other hand InP etching in HBr/Ar plasma results in a more stoichiometric surface. In contrast to the etched sidewalls, the etched surface is free from oxides with negligible traces of silicon. Exposure to ambient air of the samples submitted to Cl 2 -based chemistry results in the complete oxidation of the P-rich top layer. It is concluded that a post-etch treatment or a pure HBr plasma step may be necessary after Cl 2 -based ICP etching for the recovery of the InP material.

Band offsets in HfTiO/InGaZnO4 heterojunction determined by X-ray photoelectron spectroscopy

International Nuclear Information System (INIS)

He, G.; Chen, X.F.; Lv, J.G.; Fang, Z.B.; Liu, Y.M.; Zhu, K.R.; Sun, Z.Q.; Liu, M.

2015-01-01

Highlights: • Band offsets in HfTiO/InGaZnO 4 heterojunction were determined by XPS. • Valence band offset of HfTiO/IGZO heterojunction is determined to be 0.35 eV. • Conduction band offset of 1.61 eV is deduced for HfTiO/IGZO heterojunction. - Abstract: In current report, X-ray photoelectron spectroscopy has been pursued to obtain the valence band discontinuity (ΔE v ) of sputter deposited HfTiO/InZnGaO 4 (IGZO) heterostructures. A ΔE v value of 0.32 ± 0.1 eV was obtained by using the Ga 2p3/2, Zn 2p3/2, and In 3d5/2 energy levels as references. Taking into consideration the experimental band gaps of 5.35 eV and 3.39 eV for HfTiO and IGZO thin films measured by absorption method, respectively, this would result in a conduction band offset of 1.64 eV in this heterostructure

Efficient isotope ratio analysis of uranium particles in swipe samples by total-reflection x-ray fluorescence spectrometry and secondary ion mass spectrometry

International Nuclear Information System (INIS)

Esaka, Fumitaka; Watanabe, Kazuo; Fukuyama, Hiroyasu; Onodera, Takashi; Esaka, Konomi T.; Magara, Masaaki; Sakurai, Satoshi; Usuda, Shigekazu

2004-01-01

A new particle recovery method and a sensitive screening method were developed for subsequent isotope ratio analysis of uranium particles in safeguards swipe samples. The particles in the swipe sample were recovered onto a carrier by means of vacuum suction-impact collection method. When grease coating was applied to the carrier, the recovery efficiency was improved to 48±9%, which is superior to that of conventionally-used ultrasoneration method. Prior to isotope ratio analysis with secondary ion mass spectrometry (SIMS), total reflection X-ray fluorescence spectrometry (TXRF) was applied to screen the sample for the presence of uranium particles. By the use of Si carriers in TXRF analysis, the detection limit of 22 pg was achieved for uranium. By combining these methods with SIMS, the isotope ratios of 235 U/ 238 U for individual uranium particles were efficiently determined. (author)

Quantitative analysis of povidone-iodine thin films by X-ray photoelectron spectroscopy and their physicochemical properties

Directory of Open Access Journals (Sweden)

Sa Anongtip

2017-06-01

Full Text Available In this study, povidone-iodine (PVP-I has been formulated as a topical spray to produce a thin film for the controlled release of I2. By means of experimental design, 27 formulations containing glycerol, ethanol, PEG 400, copovidone and HFA 134a as a propellant were prepared. The pH values of all formulations were in the range of 6-7. The viscosity was within the range of 11.9-85.9 mPa s. The surface tensions were 20.3 to 24.6 mN m-1 and the contact angles were between 19.3 and 38.7°. The assays for the iodine contents were within acceptable range (80-120 %. X-ray photoelectron spectroscopy analysis revealed the ionized form of iodine was much higher than the unionized form. The MIC and MBC values of the PVP-I sprays against Staphylococcus aureus, S. epidermidis and Pseudomonas aeruginosa were higher than that of commercial PVP-I solution. The cytotoxicity study confirmed that the PVP-I spray had lower toxic effects on keratinocytes and fibroblasts compared to the commercial PVP-I solution. The formulation containing 59 % ethanol, 18 % copovidone and 12 % PEG 400 showed good antibacterial activity.

X-ray absorption and resonant photoelectron spectroscopy of epitaxial Fe-doped SrTiO{sub 3}

Energy Technology Data Exchange (ETDEWEB)

Koehl, Annemarie; Lenser, Christian; Xu, Chencheng; Wicklein, Sebastian; Dittmann, Regina [Peter Gruenberg Institut 7, Forschungszentrum Juelich GmbH (Germany); Kajewski, Dariusz; Kubacki, Jurek; Szade, Jacek [A.Chelkowski Institute of Physics, University of Silesia, Katowic (Poland)

2012-07-01

In recent years resistive switching in transition metal oxides received a lot of research interest due to the proposed application as non-volatile data memory. SrTiO{sub 3} serves as a model system for the investigation of resistive switching due to the valency change mechanism. Frequently, slightly Fe doping is used, as it has shown to improve the switching properties. The focus of this study is the effect of Fe-doping of SrTiO{sub 3} in thin epitaxial films. Thin film samples with Fe concentration of 2 at.% and 5 at.% were prepared by pulsed laser deposition at varying substrate temperatures. The surface morphology of the films is studied with AFM. X-ray absorption spectroscopy is performed in total-electron and auger-electron yield offering different probing depths. Significant variations of the Fe-L edge between bulk and interface as well as after annealing are observed and discussed in terms of integration into the lattice and evolution of secondary phases. Resonant photoelectron spectroscopy at the absorption edge of Ti, O and Fe was used to determine the spectral contributions to the valence band. Most noteworthy we find significant spectral weight above the valence band, which can be attributed to Fe-states.

TXRF, PIXE and EDXRF: a first step towards normalization of x-ray spectrometry for chemical analysis

International Nuclear Information System (INIS)

Barreiros, M.A.; Costa, M.M.; Palha, M.; Pinheiro, T.; Araujo, M.F.; Silva, R.C. da

2000-01-01

Nowadays, many research studies rely on analytical measurements to which x-ray spectrometry techniques are particularly adequate. Because they are multi-elemental, versatile, fast and can reach low detection limits they are often applied to environmental and biomedical studies. Besides, they are able to provide reliable and accurate results. As also occurs with other analytical procedures, the quality assurance for non-routine analysis in R and D laboratories, is much less well established. when compared with routine analytical work. Thus, it is of foremost importance, to set the major quality parameters that significantly affect the quality of results. In addition, there is a need to apply the new concepts of trace ability and uncertainty to these techniques. This work reports on the reliability of TXRF, PIXE and EDXRF measurements by evaluating the uncertainty and trace ability for elemental analysis. The set of experimental and statistical procedures used to ensure the quality of results relative to the proposed objectives, as well as the methods applied to estimate the uncertainties will be presented and discussed. The sample preparation procedures, analytical calibration and spectral evaluation will be the parameters examined in this inter-laboratory study. The sample preparation procedures comprise pressure acid digestion and pelletizing for solid samples. The internal quality control for analytical calibration and spectral analysis is performed using certified reference materials and standard solutions. The goal of this work is to present a first step towards normalization of x-ray spectrometry techniques for chemical analysis. (author)

Interface electronic properties of co-evaporated MAPbI3 on ZnO(0001): In situ X-ray photoelectron spectroscopy and ultraviolet photoelectron spectroscopy study

International Nuclear Information System (INIS)

Zhou, Xianzhong; Li, Xiaoli; Huang, Feng; Zhong, Dingyong; Liu, Yuan

2016-01-01

In this work, the interface electronic properties of ZnO(0001)/CH 3 NH 3 PbI 3 were investigated by both X-ray and ultraviolet photoelectron spectroscopy. The CH 3 NH 3 PbI 3 thin films were grown on single crystalline ZnO(0001) substrate in situ by co-evaporation of PbI 2 and CH 3 NH 3 I at room temperature with various thickness from 1.5 nm to 190 nm. It was found that the conduction band minimum of ZnO lies 0.3 eV below that of CH 3 NH 3 PbI 3 , while the valence band maximum of ZnO lies 2.1 eV below that of CH 3 NH 3 PbI 3 , implying that the electrons can be effectively transported from CH 3 NH 3 PbI 3 to ZnO, and the holes can be blocked in the same time. A PbI 2 rich layer was initially formed at the interface of ZnO(0001)/CH 3 NH 3 PbI 3 during the growth. As a consequence, an interface barrier was built up which may prevent the electron transport at the interface.

Electronic structure of the polymer-cathode interface of an organic electroluminescent device investigated using operando hard x-ray photoelectron spectroscopy

Energy Technology Data Exchange (ETDEWEB)

Ikeuchi, J.; Hamamatsu, H.; Miyamoto, T. [Sumitomo Chemical Co., Ltd., Advanced Materials Research Laboratory, 6 Kitahara, Tsukuba, Ibaraki 300-3294 (Japan); Tanaka, S. [Sumitomo Chemical Co., Ltd., Tsukuba Material Development Laboratory, 6 Kitahara, Tsukuba, Ibaraki 300-3294 (Japan); Yamashita, Y.; Yoshikawa, H.; Ueda, S. [National Institute for Materials Science, Synchrotron X-ray Station at SPring-8, Sayo-cho, Sayo-gun, Hyogo 679-5148 (Japan)

2015-08-28

The electronic structure of a polymer-cathode interface of an operating organic light-emitting diode (OLED) was directly investigated using hard X-ray photoelectron spectroscopy (HAXPES). The potential distribution profile of the light-emitting copolymer layer as a function of the depth under the Al/Ba cathode layer in the OLED depended on the bias voltage. We found that band bending occurred in the copolymer of 9,9-dioctylfluorene (50%) and N-(4-(2-butyl)-phenyl)diphenylamine (F8-PFB) layer near the cathode at 0 V bias, while a linear potential distribution formed in the F8-PFB when a bias voltage was applied to the OLED. Direct observation of the built-in potential and that band bending formed in the F8-PFB layer in the operating OLED suggested that charges moved in the F8-PFB layer before electron injection from the cathode.

Electronic structure of the polymer-cathode interface of an organic electroluminescent device investigated using operando hard x-ray photoelectron spectroscopy

International Nuclear Information System (INIS)

Ikeuchi, J.; Hamamatsu, H.; Miyamoto, T.; Tanaka, S.; Yamashita, Y.; Yoshikawa, H.; Ueda, S.

2015-01-01

The electronic structure of a polymer-cathode interface of an operating organic light-emitting diode (OLED) was directly investigated using hard X-ray photoelectron spectroscopy (HAXPES). The potential distribution profile of the light-emitting copolymer layer as a function of the depth under the Al/Ba cathode layer in the OLED depended on the bias voltage. We found that band bending occurred in the copolymer of 9,9-dioctylfluorene (50%) and N-(4-(2-butyl)-phenyl)diphenylamine (F8-PFB) layer near the cathode at 0 V bias, while a linear potential distribution formed in the F8-PFB when a bias voltage was applied to the OLED. Direct observation of the built-in potential and that band bending formed in the F8-PFB layer in the operating OLED suggested that charges moved in the F8-PFB layer before electron injection from the cathode

Electronic structure of the polymer-cathode interface of an organic electroluminescent device investigated using operando hard x-ray photoelectron spectroscopy

Science.gov (United States)

Ikeuchi, J.; Hamamatsu, H.; Miyamoto, T.; Tanaka, S.; Yamashita, Y.; Yoshikawa, H.; Ueda, S.

2015-08-01

The electronic structure of a polymer-cathode interface of an operating organic light-emitting diode (OLED) was directly investigated using hard X-ray photoelectron spectroscopy (HAXPES). The potential distribution profile of the light-emitting copolymer layer as a function of the depth under the Al/Ba cathode layer in the OLED depended on the bias voltage. We found that band bending occurred in the copolymer of 9,9-dioctylfluorene (50%) and N-(4-(2-butyl)-phenyl)diphenylamine (F8-PFB) layer near the cathode at 0 V bias, while a linear potential distribution formed in the F8-PFB when a bias voltage was applied to the OLED. Direct observation of the built-in potential and that band bending formed in the F8-PFB layer in the operating OLED suggested that charges moved in the F8-PFB layer before electron injection from the cathode.

Quantitative analysis of phosphosilicate glass films on silicon wafers for calibration of x-ray fluorescence spectrometry standards

International Nuclear Information System (INIS)

Weissman, S.H.

1983-01-01

The phosphorus and silicon contents of phosphosilicate glass films deposited by chemical vapor deposition (CVD) on silicon wafers were determined. These films were prepared for use as x-ray fluorescence (XRF) spectrometry standards. The thin films were removed from the wafer by etching with dilute hydrofluoric acid, and the P and Si concentrations in solution were determined by inductively coupled plasma atomic emission spectroscopy (ICP). The calculated phosphorus concentration ranged from 2.2 to 12 wt %, with an uncertainty of 2.73 to 10.1 relative percent. Variation between the calculated weight loss (summation of P 2 O 5 and SiO 2 amounts as determined by ICP) and the measured weight loss (determined gravimetrically) averaged 4.9%. Results from the ICP method, Fourier transform-infrared spectroscopy (FT-IR), dispersive infrared spectroscopy, electron microprobe, and x-ray fluorescence spectroscopy for the same samples are compared

Surface-specific analytical techniques

International Nuclear Information System (INIS)

Riviere, J.C.

1982-01-01

The following methods are discussed: electron excitation (Auger electron spectroscopy; scanning Auger microscopy; electron energy-loss spectroscopy; appearance potential spectroscopy; electron-induced luminescence; electron-stimulated desorption); photon excitation (X-ray photoelectron spectroscopy; X-ray excited Auger electron spectroscopy; synchrotron radiation photoelectron spectroscopy; ultraviolet photoelectron spectroscopy; photoelectron spectromicroscopy; ellipsometry); ion excitation (ion-excited Auger electron spectroscopy; proton-excited Auger electron spectroscopy; ion neutralization spectroscopy; ion beam spectrochemical analysis; glow discharge optical spectroscopy; static secondary ion mass spectrometry; ion scattering spectroscopy; glow discharge mass spectrometry); resolution and sensitivity. (U.K.)

In situ chemical state analysis of buried polymer/metal adhesive interface by hard X-ray photoelectron spectroscopy

International Nuclear Information System (INIS)

Ozawa, Kenichi; Kakubo, Takashi; Shimizu, Katsunori; Amino, Naoya; Mase, Kazuhiko; Ikenaga, Eiji; Nakamura, Tetsuya; Kinoshita, Toyohiko; Oji, Hiroshi

2014-01-01

Highlights: • Chemical state analysis of the buried rubber/brass interface is conducted by HAXPES. • Ultrathin rubber films are prepared on the brass surface by two methods. • A high density of Cu 2 S is found on the rubber side of the buried adhesive layer. • The chemical states of the buried and exposed interfaces are compared. - Abstract: Chemical state analysis of adhesive interfaces is important to understand an adhesion mechanism between two different materials. Although photoelectron spectroscopy (PES) is an ideal tool for such an analysis, the adhesive interfaces must be exposed to the surface because PES is essentially a surface sensitive technique. However, an in situ observation is possible by hard X-ray PES (HAXPES) owing to its large probing depth. In the present study, HAXPES is applied to investigate the adhesive interface between rubber and brass without exposing the interface. It is demonstrated that copper sulfides formed at the buried rubber/brass interface are distinguished from S-containing species in the rubber overlayer. The chemical state of the buried interface is compared with that of the “exposed” interface prepared by so-called a filter-paper method

Analysis of metal-laden water via portable X-ray fluorescence spectrometry

Science.gov (United States)

Pearson, Delaina; Weindorf, David C.; Chakraborty, Somsubhra; Li, Bin; Koch, Jaco; Van Deventer, Piet; de Wet, Jandre; Kusi, Nana Yaw

2018-06-01

A rapid method for in-situ elemental composition analysis of metal-laden water would be indispensable for studying polluted water. Current analytical lab methods to determine water quality include flame atomic absorption spectrometry (FAAS), atomic absorption spectrophotometry (AAS), electrothermal atomic absorption spectrometry (EAAS), and inductively coupled plasma (ICP) spectroscopy. However only two field methods, colorimetry and absorptiometry, exist for elemental analysis of water. Portable X-ray fluorescence (PXRF) spectrometry is an effective method for elemental analysis of soil, sediment, and other matrices. However, the accuracy of PXRF is known to be affected while scanning moisture-laden soil samples. This study sought to statistically establish PXRF's predictive ability for various elements in water at different concentrations relative to inductively coupled plasma atomic emission spectroscopy (ICP-AES). A total of 390 metal-laden water samples collected from leaching columns of mine tailings in South Africa were analyzed via PXRF and ICP-AES. The PXRF showed differential effectiveness in elemental quantification. For the collected water samples, the best relationships between ICP and PXRF elemental data were obtained for K and Cu (R2 = 0.92). However, when scanning ICP calibration solutions with elements in isolation, PXRF results indicated near perfect agreement; Ca, K, Fe, Cu and Pb produced an R2 of 0.99 while Zn and Mn produced an R2 of 1.00. The utilization of multiple PXRF (stacked) beams produced stronger correlation to ICP relative to the use of a single beam in isolation. The results of this study demonstrated the PXRF's ability to satisfactorily predict the composition of metal-laden water as reported by ICP for several elements. Additionally this study indicated the need for a "Water Mode" calibration for the PXRF and demonstrates the potential of PXRF for future study of polluted or contaminated waters.

Soft X-ray spectroscopy of transition metal compounds: a theoretical perspective

International Nuclear Information System (INIS)

Bokarev, S.I.; Hilal, R.; Aziz, S.G.; Kühn, O.

2017-01-01

To date, X-ray spectroscopy has become a routine tool that can reveal highly local and element-specific information on the electronic structure of atoms in complex environments. Here, we report on the development of an efficient and versatile theoretical methodology for the treatment of soft X-ray spectra of transition metal compounds based on the multi-configurational self-consistent field electronic structure theory. A special focus is put on the L-edge photon-in/photon-out and photon-in/electron-out processes, i.e. X-ray absorption, resonant inelastic scattering, partial fluorescence yield, and photoelectron spectroscopy, all treated on the same theoretical footing. The investigated systems range from small prototypical coordination compounds and catalysts to aggregates of biomolecules.

The (CuGaSe{sub 2}){sub 1-x}(MgSe){sub x} alloy system (0{<=}x{<=}0.5): X-ray diffraction, energy dispersive spectrometry and differential thermal analysis

Energy Technology Data Exchange (ETDEWEB)

Grima Gallardo, P.; Munoz, M.; Ruiz, J. [Centro de Estudios en Semiconductores (C.E.S.), Dpto. Fisica, Fac. Ciencias, La Hechicera, Merida (Venezuela); Delgado, G.E. [Laboratorio de Cristalografia, Dpto. Quimica, Fac. Ciencias, Universidad de Los Andes, Merida 5101 (Venezuela); Briceno, J.M. [Laboratorio de Analisis Quimico y Estructural (LAQUEM), Dpto. Fisica, Fac. Ciencias, La Hechicera, Merida (Venezuela)

2004-07-01

The (CuGaSe{sub 2}){sub 1-x}(MgSe){sub x} alloy system (0<x{<=}0.5) was investigated using X-ray powder diffraction, energy dispersion spectrometry and differential thermal analysis. The solubility of MgSe in CuGaSe{sub 2} was found to be nearly complete for all the compositions studied, although traces of MgSe appear as a secondary phase at x{>=}0.15. All the alloys showed the chalcopyrite structure and the lattice parameters of the unit cell do not follow a linear behavior but showed a soft local maximum at x {proportional_to} 0.15. In the single-phase field, the increasing behavior of the lattice parameters can be reproduced using an extension for quaternary alloys of Jaffe and Zunger's model for chalcopyrites. (copyright 2004 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

Deposition of thin layer (monoatomic layer) of barium on gold single crystal surfaces and studies of its oxidation employing X-ray photoelectron spectroscopy

International Nuclear Information System (INIS)

Ahmad, H.; Ahmad, R.; Khalid, M.; Alvi, R.A.

2007-01-01

Due to the high reactivity of barium with oxygen, some oxygen diffuse into the bulk to form bulk oxide and it is very difficult to differentiate the oxide over layer and the bulk oxide. To study the oxidation of barium surface layer, a thin layer (monolayer) of barium is developed over gold single crystal surface. Gold is selected as support because it is one of the least reactive metal in transition metal group and have very low probability of reaction with oxygen at room temperature (300K). Nitrous oxide (N/sub 2/O) was used as oxidant. Thin layer of barium was deposited on Au(100) surface. The barium coverage on gold surface was calculated that varied from 0.4 to 1.4 monolayer (ML). Photoelectron spectra for O(ls), N(ls), Ba (3d), and Au (4f) have been recorded on X-ray photoelectron spectrometer at different binding energy region specific for each element. The decomposition of nitrous oxide has been observed in all cases. It has found that nitrogen is evolved in the gaseous state and oxygen is adsorbed/chemisorbed on barium over layer. (author)

System for Gamma an X rays fluorescence spectrometric

International Nuclear Information System (INIS)

Alonso Abad, D.; Arista Romeu, E.; Bolanos Perez, L. and others

1997-01-01

A system for spectrometry of gamma or fluorescence X rays is presented. It sis composed by a Si(Li) semiconductors detector, a charge sensitive preamplifier, a high voltage power supply, a spectrometric amplifier and a monolithic 1024 channels multichannel analyzers or an IBM compatible 4096 channels add - on- card multichannel analyzer. The system can be configured as a 1024 or 4096 channels gamma or fluorescent X rays spectrometer

The study of electric erosion treatments of Ni-superalloys by ion-scattering spectrometry and X-ray analysis

International Nuclear Information System (INIS)

Betsofen, S.Ya.; Borisov, A.M.; Sarychev, S.M.; Romanovskij, E.A.; Bakui Ali; Bespalova, O.V.; Kulikauskas, V.S.; Serkov, M.V.; Grigorovich, K.V.

2004-01-01

The study results are reported for a surface layer of a nickel base heat resistant alloy of the following composition, mas.%: Ni-8.2 Cr-10.5 W-15.5 Co-2.4 Mo-1.4 Nb-4.8 Al-0.2 C, after electroerosion. With the use of Rutherford and nuclear backscattering spectrometry and X-ray diffraction analysis it is revealed that melting under electroerosion results in redistribution of alloying elements, enrichment with carbon and occurrence of residual tensile stresses [ru

Polarity of wurtzite crystals by photoelectron diffraction

Czech Academy of Sciences Publication Activity Database

Bartoš, Igor; Romanyuk, Olexandr

2014-01-01

Roč. 315, OCT (2014), s. 506-509 ISSN 0169-4332 Grant - others:AVČR(CZ) M100101201 Institutional support: RVO:68378271 Keywords : wurtzite semiconductors * surface polarity * X-ray photoelectron diffraction * XPD Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 2.711, year: 2014 http://www.sciencedirect.com/science/article/pii/S016943321400066X

Tribocharging in electrostatic beneficiation of coal: Effects of surface composition on work function as measured by x-ray photoelectron spectroscopy and ultraviolet photoelectron spectroscopy in air

International Nuclear Information System (INIS)

Trigwell, S.; Mazumder, M.K.; Pellissier, R.

2001-01-01

The cleaning of coal by electrostatic beneficiation is based on tribocharging characteristics of pulverized coal particles with diameter smaller than 120 μm. The tribocharging process should be such that the organic coal particles must charge with a polarity opposite to that of the sulfur and the mineral containing particles so that coal can be separated from minerals by using a charge separator. However, the charge distribution of electrostatically separated coal particles indicates that coal exhibits bipolar charging. A significant fraction of the coal particles charges negatively which appears to be in conflict with expectations in that the organic coal particles should charge positively, and the mineral particles, present as impurities such as pyrite, charge negatively when tribocharged against copper. The relative work functions of the particles (coal and mineral) and that of the metal surface (copper or stainless steel) used for tribocharging predict these expected results. However, ultraviolet photoelectron spectroscopy (UPS) measurements in air on specimens of three different coal species, showed the work function to be approximately 5.4 eV, which is higher than a reported measured work function of 3.93 eV. Studies by UPS and x-ray photoelectron spectroscopy on copper, stainless steel, aluminum, and other commonly used tribocharging materials such as nylon and polytetrafluorethylene, as well as pure pyrite, showed that the work function varied considerably as a function of surface composition. Therefore, the reason for the bipolar charging of the coal particles may be the too small differences in work functions between coal powder and copper used as the charging material. The choice of a material for impaction triboelectric charging for coal or mineral separation should therefore depend upon the actual work function as modified by the ambient conditions such as moisture content and the oxidation of the surface

Heavy metal determination by X-rays spectrometry for superficial sediments at Guantanamo bay

International Nuclear Information System (INIS)

Gelen, A.; Izquierdo; Corrales, W. Y.; Lopez, N.; Casanova, A. O.; Diaz, O.; Manso, M.V.; D Alessandro, K.; Reyes, E.; Toledo, C.; Ruiz, F.; Ramirez, M.; Beltran, J.; Martin, A.

2007-01-01

Twelve surface samples of the Guantanamo Bay (Cuba) were collected and analysed by X-Rays Spectrometry. Twenty one elements (Si, Ca, K, Na, P, S, Cl, Al, Fe, Mg, Ti, Mn, C, O, Cr, Cu, Ni, Co, Pb, V and Zn) have been determined. The distribution of the metals is associated with the wastewater from anthropogenic origin that receives the bay, mainly by fluvial currents. Multivariate statistical were used for the analysis of the results. Finally the results analysed were compared with the analysis performed by Engineering Centre for Environmental Management of Bays and Coasts (Cimab) using Inductively Coupled Plasma Emission (ICP) for some elements such as: Cr, Cu, Fe, Ni, Pb, V and Zn. The results show the Guantanamo Bay is less polluted than others Cuban Bays. (Author)

X-ray photoelectron spectroscopy (XPS) investigation of the surface film on magnesium powders.

Science.gov (United States)

Burke, Paul J; Bayindir, Zeynel; Kipouros, Georges J

2012-05-01

Magnesium (Mg) and its alloys are attractive for use in automotive and aerospace applications because of their low density and good mechanical properties. However, difficulty in forming magnesium and the limited number of available commercial alloys limit their use. Powder metallurgy may be a suitable solution for forming near-net-shape parts. However, sintering pure magnesium presents difficulties due to surface film that forms on the magnesium powder particles. The present work investigates the composition of the surface film that forms on the surface of pure magnesium powders exposed to atmospheric conditions and on pure magnesium powders after compaction under uniaxial pressing at a pressure of 500 MPa and sintering under argon at 600 °C for 40 minutes. Initially, focused ion beam microscopy was utilized to determine the thickness of the surface layer of the magnesium powder and found it to be ~10 nm. The X-ray photoelectron analysis of the green magnesium sample prior to sintering confirmed the presence of MgO, MgCO(3)·3H(2)O, and Mg(OH)(2) in the surface layer of the powder with a core of pure magnesium. The outer portion of the surface layer was found to contain MgCO(3)·3H(2)O and Mg(OH)(2), while the inner portion of the layer is primarily MgO. After sintering, the MgCO(3)·3H(2)O was found to be almost completely absent, and the amount of Mg(OH)(2) was also decreased significantly. This is postulated to occur by decomposition of the compounds to MgO and gases during the high temperature of sintering. An increase in the MgO content after sintering supports this theory.

Use of portable X-ray fluorescence spectrometry for environmental quality assessment of peri-urban agriculture.

Science.gov (United States)

Weindorf, David C; Zhu, Yuanda; Chakraborty, Somsubhra; Bakr, Noura; Huang, Biao

2012-01-01

Urban expansion into traditional agricultural lands has augmented the potential for heavy metal contamination of soils. This study examined the utility of field portable X-ray fluorescence (PXRF) spectrometry for evaluating the environmental quality of sugarcane fields near two industrial complexes in Louisiana, USA. Results indicated that PXRF provided quality results of heavy metal levels comparable to traditional laboratory analysis. When coupled with global positioning system technology, the use of PXRF allows for on-site interpolation of heavy metal levels in a matter of minutes. Field portable XRF was shown to be an effective tool for rapid assessment of heavy metals in soils of peri-urban agricultural areas.

Photoelectronic radiology 1983; X-ray imaging with the computer-assisted technologies

International Nuclear Information System (INIS)

Chalaoui, J.; Sylvestre, J.; Robillard, P.; Dussault, R.

1984-01-01

The development of the discipline of radiology has continued to progress from initial images depicting the structure of organs, to the exploration of dynamic and physiologic phenomena, improvements in the power of X-ray generators and with the refinement of non-toxic contrast media. Until the early part of the 1970s, radiology consisted in extrapolations from a two-dimensional image of a three-dimensional organ, and advances in diagnostic quality related chiefly to improvements in spatial resolution of the flat image. With the advent of cross-sectional imaging using computer reconstruction the emphasis has shifted to contrast resolution, to the acquisition of ''pure'' images in the XY plane and to an area-related approach in diagnosis, rather than to the traditional organ-oriented method. This new trend has only been made possible because of the influence of recent developments in the digital and electronics industry. This history of diagnostic radiology up to 1972 is reviewed, followed by a discussion of the major areas of interaction between X-ray and the computer, as represented by the major leading edge technologies that have already received broad acceptance by the health care profession. (author)

Asian conference on x-rays and related techniques in research and industry. Proceedings

International Nuclear Information System (INIS)

1996-01-01

This proceedings compile the paper presented at the conference. The papers for presentation are from wide spectrum stressing the interdisciplinary nature of the conference i.e. x-ray fluorescence spectrometry (XRF), x-ray diffraction (XRD), TEM, scanning electron microscope (SEM), energy dispersive x-ray (EDX), auger electron microscopy, electron back scatter diffraction (EBSD)

Mechanism of electron transfer in the bioadsorption of hexavalent chromium within Leersia hexandra Swartz granules by X-ray photoelectron spectroscopy

Energy Technology Data Exchange (ETDEWEB)

Li Jianping, E-mail: likianping@263.net [College of Chemistry and Bioengineering, Guilin University of Technology, Guilin 541004 (China) and Guangxi Key Laboratory of Environmental Engineering, Protection and Assessment, Guilin 541004 (China); Lin Qingyu [College of Chemistry and Bioengineering, Guilin University of Technology, Guilin 541004 (China); Zhang Xuehong [Guangxi Key Laboratory of Environmental Engineering, Protection and Assessment, Guilin 541004 (China)

2010-10-15

Leersia hexandra Swartz biogranules were used to adsorb Cr(VI) from aqueous solutions. Batch biosorption experiments showed that the Cr(VI) concentration sharply decreases in the first 15 min. The main functional groups that may be involved in chromium sorption were determined using Fourier transform infrared spectroscopy. The use of X-ray photoelectron spectroscopy confirmed the reduction of Cr(VI) to Cr(III) through L. hexandra Sw. Results indicate that Cr(III) is the dominant species on the surface of the biogranules and that the redox reaction can be accomplished within 40 min. The mechanism of electron transfer during Cr(VI) reduction to Cr(III) was investigated. Protonation of the oxygen-containing groups produces electrostatic-sorption power over Cr(VI). The nitrogen-containing groups serve as the electron-donor groups in the process of reduction-sorption. Moreover, after the complete reduction of Cr(VI), the pH of the suspension significantly increases.

Surface cleaning and preparation in AlGaN/GaN-based HEMT processing as assessed by X-ray photoelectron spectroscopy

International Nuclear Information System (INIS)

Gonzalez-Posada, Fernando; Bardwell, Jennifer A.; Moisa, Simona; Haffouz, Soufien; Tang, Haipeng; Brana, Alejandro F.; Munoz, Elias

2007-01-01

The chemical composition of the AlGaN/GaN surface during typical process steps in transistor fabrication was studied using X-ray photoelectron spectroscopy (XPS). The steps studied included organic solvent cleaning, 1:1 HCl:H 2 O dip, buffered oxide etch dip, oxygen plasma descum and rapid thermal annealing (RTA). The surface composition was calculated after correction for the interference of the Ga Auger lines in the N 1s portion of the spectra. The buffered oxide etched (BOE) surface showed a greater tendency for Al (compared to Ga) to be oxidized in the surface, under a layer of adventitious carbon. Three different treatments were found to yield a combination of low C and O levels in the surface. Both plasma cleaning and RTA were highly effective at reducing the carbon contamination of the surface, but did increase the oxygen levels. The RTA treated surface was found to have low levels of oxygen incorporation to a depth of 2-6 nm

Determination of sulphur with total reflection x-ray spectrometry

International Nuclear Information System (INIS)

Steinmeyer, S.; Kolbesen, B.O.

2000-01-01

The potential and limitations of total reflection x-ray spectrometry (TXRF) were tested for the quantitative determination of the light element sulphur in inorganic and biological samples. As representatives of inorganic samples alkali, transition metal, magnesium and aluminum sulphates were investigated. As biological samples the sulphur containing amino acid methionine and the pharmaceutical drug insulin were chosen. All measurements were performed on a TXRF-spectrometer EXTRA IIA (Atomika Instruments, Oberschleissheim/Germany) using tungsten L-radiation as the excitation tube. Various concentrations of all samples ranging from 20 mg/l to 0.5 mg/l were determined. In addition the surface topography and thickness of the dry residue of these samples were investigated with SEM and a thickness profilometer (Alpha-Step). The result show that the reliable determination of sulphur in sulphates depends on the cation involved. Alkali sulphates like Na 2 SO 4 , or K 2 SO 4 form bulky residues resulting in significant deviations of the recovery rate of sulphur. In this case the use of smoothing detergents like 1 % HF, 1 % malic acid and 2 % hydrazinhydrat was found to be necessary for accurate determination. The results for the biological samples agree well with the expected values. The investigations lead to the conclusion that TXRF combined with a proper samples preparation is well suited for the determination of sulphur in different samples with various concentrations and matrices. (author)

Determination of Fe in blood using portable X-ray fluorescence spectrometry: an alternative for sports medicine

International Nuclear Information System (INIS)

Zamboni, C.B.; Metairon, S.; Kovacs, L.; Macedo, D.V.; Rizzutto, M.A.

2016-01-01

An alternate methodology based on a portable X-ray fluorescence spectrometry (PXRFS) for determination of Fe in blood was evaluated. The iron concentrations was determined in whole blood of 18 male amateur athletes (runners) using this portable XRF spectrometer and compared with a control group (54 male donors at the same age but not involved with physical activities) obtained by XRF and NAA techniques. The Fe concentration in the blood of runners is an important factor in sports medicine contributing to the performance of endurance athletes as well as for proposing new protocols of clinical evaluation. (author)

Angle-resolved environmental X-ray photoelectron spectroscopy: A new laboratory setup for photoemission studies at pressures up to 0.4 Torr

International Nuclear Information System (INIS)

Mangolini, F.; Wabiszewski, G. E.; Egberts, P.; Åhlund, J.; Backlund, K.; Karlsson, P. G.; Adiga, V. P.; Streller, F.; Wannberg, B.; Carpick, R. W.

2012-01-01

The paper presents the development and demonstrates the capabilities of a new laboratory-based environmental X-ray photoelectron spectroscopy system incorporating an electrostatic lens and able to acquire spectra up to 0.4 Torr. The incorporation of a two-dimensional detector provides imaging capabilities and allows the acquisition of angle-resolved data in parallel mode over an angular range of 14° without tilting the sample. The sensitivity and energy resolution of the spectrometer have been investigated by analyzing a standard Ag foil both under high vacuum (10 −8 Torr) conditions and at elevated pressures of N 2 (0.4 Torr). The possibility of acquiring angle-resolved data at different pressures has been demonstrated by analyzing a silicon/silicon dioxide (Si/SiO 2 ) sample. The collected angle-resolved spectra could be effectively used for the determination of the thickness of the native silicon oxide layer.

Calibration comparative results for X - and gamma ray spectrometry with HPGe and BEGe detectors for a radon reference chamber

International Nuclear Information System (INIS)

Zoran, Maria; Paul, Annette; Arnold, Dirk

2002-01-01

Inhaled decay products of 222 Rn are the dominant components of the natural radiation exposure being responsible for about 30% of the whole human radioactive exposure. Field instruments for 222 Rn and his progeny monitoring are calibrated in 'radon climate rooms', where it is possible to vary and monitor 222 Rn and the indoor air parameters ( temperature, humidity, ventilation rate, aerosol concentration). German radon reference chamber used was developed and installed at the Physikalisch-Technische Bundesanstalt in order to serve as a metrological standard for radon and his progeny calibration of active and passive, indoor and outdoor radon monitoring devices in air climate. The basic parts of experimental setup for this γ and X -ray spectrometry analysis consists of a γ-X ray source in a lead shield/collimator, the detectors, the electronics necessary for pulse-height analysis (PHA) to obtain energy spectra. For calibrating system with 226 Ra standard sources (multienergy X ray and gamma emitters), two germanium detectors HPGe (12.5 nominal efficiency) and BEGe (22.5 nominal efficiency) were used. Germanium detectors are semiconductor diodes having a P-I-N structure in which the Intrinsic (I) region is sensitive to ionizing radiation, particularly X-rays and gamma rays. The BEGe is designed with an electrode structure that enhances low energy resolution and is fabricated from selected germanium having an impurity profile that improves charge collection (thus resolution and peak shape) at high energies which is really important in analysis of the complex spectra for uranium and finally for 226 Ra. MAESTRO MCA software and GNUPLOT program were used for spectra acquisition and spectra analysis, respectively . The main aim of this paper was to do a comparatively analysis of the detector performances for this radon chamber spectrometric chain. The calibration data analysis includes energy calibrations for both detection systems as well as comparative X and gamma

X-ray photoelectron spectroscopy and secondary electron yield analysis of Al and Cu samples exposed to an accelerator environment

Science.gov (United States)

Rosenberg, R. A.; McDowell, M. W.; Ma, Q.; Harkay, K. C.

2003-09-01

It is well known that exposure to an accelerator environment can cause ``conditioning'' of the vacuum chamber surfaces. In order to understand the manner in which the surface structure might influence the production of gases and electrons in the accelerator, such surfaces should be studied both before and after exposure to accelerator conditions. Numerous studies have been performed on representative materials prior to being inserted into an accelerator, but very little has been done on materials that have ``lived'' in the accelerator for extended periods. In the present work, we mounted Al and Cu coupons at different positions in a section of the Advanced Photon Source storage ring and removed them following exposures ranging from 6 to 18 months. X-ray photoelectron spectroscopy (XPS) of the surface was performed before and after exposure. Changes were observed that depended on the location and whether the coupon was facing the chamber interior or chamber wall. These results will be presented and compared to XPS and secondary electron yield data obtained from laboratory measurements meant to simulate the accelerator conditions.

Many-electron theory of x-ray photoelectron spectra: N-shell linewidths in the 46Pd to 92U range

International Nuclear Information System (INIS)

Ohno, M.; Wendin, G.

1985-01-01

The linewidths and energies of 4d holes (main lines in x-ray photoelectron spectra) are calculated for a number of elements in the range 70 Yb to 92 U, with use of nonrelativistic atomic many-body theory. The nonrelativistic Hartree-Fock frozen-core approximation for one-electron wave functions and Auger energies gives very good agreement with experiment. In the case of 4s and 4p holes, the Auger (in particular, super-Coster-Kronig) energies have to be calculated with inclusion of relaxation and relativistic effects. Combined with frozen-core, nonrelativistic one-electron wave functions, this gives good agreement with experimental energies and widths for 4s and 4p holes in 80 Hg. In conclusion, it is very important to include the effects of two final-state holes on the Auger electron, as well as the polarization response which screens the Auger emission matrix element. This latter effect is largely equivalent to the so-called exchange interaction between the Auger electron and the final-state holes

Band offsets in HfTiO/InGaZnO{sub 4} heterojunction determined by X-ray photoelectron spectroscopy

Energy Technology Data Exchange (ETDEWEB)

He, G., E-mail: ganghe01@issp.ac.cn [School of Physics and Materials Science, Radiation Detection Materials & Devices Lab, Anhui University, Hefei 230601 (China); Chen, X.F. [School of Physics and Materials Science, Radiation Detection Materials & Devices Lab, Anhui University, Hefei 230601 (China); Lv, J.G., E-mail: jglv@hftc.edu.cn [School of Electronic and Information Engineering, Hefei Normal University, Hefei 230601 (China); Fang, Z.B., E-mail: csfzb@usx.edu.cn [Department of Physics, Shaoxing University, Shaoxing 312000 (China); Liu, Y.M.; Zhu, K.R.; Sun, Z.Q. [School of Physics and Materials Science, Radiation Detection Materials & Devices Lab, Anhui University, Hefei 230601 (China); Liu, M., E-mail: mliu@issp.ac.cn [Key Laboratory of Materials Physics, Anhui Key Laboratory of Nanomaterials and Nanostructure, Institute of Solid State Physics, Chinese Academy of Sciences, Hefei 230031 (China)

2015-09-05

Highlights: • Band offsets in HfTiO/InGaZnO{sub 4} heterojunction were determined by XPS. • Valence band offset of HfTiO/IGZO heterojunction is determined to be 0.35 eV. • Conduction band offset of 1.61 eV is deduced for HfTiO/IGZO heterojunction. - Abstract: In current report, X-ray photoelectron spectroscopy has been pursued to obtain the valence band discontinuity (ΔE{sub v}) of sputter deposited HfTiO/InZnGaO{sub 4} (IGZO) heterostructures. A ΔE{sub v} value of 0.32 ± 0.1 eV was obtained by using the Ga 2p3/2, Zn 2p3/2, and In 3d5/2 energy levels as references. Taking into consideration the experimental band gaps of 5.35 eV and 3.39 eV for HfTiO and IGZO thin films measured by absorption method, respectively, this would result in a conduction band offset of 1.64 eV in this heterostructure.

Determination of trace metals in nuclear-grade uranium dioxide by X-ray fluorescence spectrometry

International Nuclear Information System (INIS)

Salvador, V.L.R.; Imakuma, K.

1988-04-01

A method is described for the simultaneous determination of low concentrations of Ca, Cr, Cu, Fe, Mn and Ni in nuclear-grade uranium dioxide by X-ray fluorescence spectrometry, without the use of chemical treatment. The lower limits of detection range from 2 μg g -1 for nickel and manganese to 5 μg g -1 for copper. Samples are prepared in the form of double-layer pellets with boric acid as a binding agent. Standards are prepared in a U 3 O 8 matrix, which is more chemically stable than UO 2 and has similar matrix behaviour. The correlation coefficients for calibration curves are better than 0.999. Erros range from 2.4 % for chromium to 6.8 % for nickel. (author) [pt

Optimising the design of gas microstrip detectors for soft x-ray detection

International Nuclear Information System (INIS)

Bateman, J.; Barlow, R.; Derbyshire, G.

2001-01-01

This report describes development work in which systematic changes in the electrode pattern of a Gas Microstrip Detector are explored in the search for higher avalanche gains and enhanced stability. It is found that the width of the cathode structure is the main determinant of the detector stability. With the correct cathode width, gas gains of >50 000 are comfortably attainable with low detector noise so that x-rays can potentially be detected down to the limit of a single x-ray-produced photoelectron. (author)

Identifying isomers of C-78 by means of x-ray spectroscopy

DEFF Research Database (Denmark)

Bassan, Arianna; Nyberg, Mats; Luo, Yi

2002-01-01

X-ray photoelectron and absorption spectra of C-78 isomers have been generated using density functional theory with inclusion of the full core-hole potentials. Strong isomer dependence has been found in absorption, but not in the photoelectron spectra. C-78 isomers can be thought to be formed by ...... by inserting 18 carbon atoms into an opened C-60. We have shown how the different local arrangements of these 18 carbon atoms are responsible for the significant isomer dependence observed. Our calculated spectra are in excellent agreement with the experimental counterparts....

Quantitative x-ray photoelectron spectroscopy: Simple algorithm to determine the amount of atoms in the outermost few nanometers

International Nuclear Information System (INIS)

Tougaard, Sven

2003-01-01

It is well known that due to inelastic electron scattering, the measured x-ray photoelectron spectroscopy peak intensity depends strongly on the in-depth atom distribution. Quantification based only on the peak intensity can therefore give large errors. The problem was basically solved by developing algorithms for the detailed analysis of the energy distribution of emitted electrons. These algorithms have been extensively tested experimentally and found to be able to determine the depth distribution of atoms with nanometer resolution. Practical application of these algorithms has increased after ready-to-use software packages were made available and they are now being used in laboratories worldwide. These software packages are easy to use but they need operator interaction. They are not well suited for automatic data processing and there is an additional need for simplified quantification strategies that can be automated. In this article we report on a very simple algorithm. It is a slightly more accurate version of our previous algorithm. The algorithm gives the amount of atoms within the outermost three inelastic mean free paths and it also gives a rough estimate for the in-depth distribution. An experimental example of its application is also presented

X-ray photoelectron spectroscopy study of the passive films formed on thermally sprayed and wrought Inconel 625

Energy Technology Data Exchange (ETDEWEB)

Bakare, M.S. [Materials, Mechanics and Structures Research Division, Faculty of Engineering, University of Nottingham, University Park, Nottingham, NG7 2RD (United Kingdom); Voisey, K.T., E-mail: Katy.voisey@nottingham.ac.uk [Materials, Mechanics and Structures Research Division, Faculty of Engineering, University of Nottingham, University Park, Nottingham, NG7 2RD (United Kingdom); Roe, M.J.; McCartney, D.G. [Materials, Mechanics and Structures Research Division, Faculty of Engineering, University of Nottingham, University Park, Nottingham, NG7 2RD (United Kingdom)

2010-11-15

There is a well known performance gap in corrosion resistance between thermally sprayed corrosion resistant coatings and the equivalent bulk materials. Interconnected porosity has an important and well known effect, however there are additional relevant microstructural effects. Previous work has shown that a compositional difference exists between the regions of resolidified and non-melted material that exist in the as-sprayed coatings. The resolidified regions are depleted in oxide forming elements due to formation of oxides during coating deposition. Formation of galvanic cells between these different regions is believed to decrease the corrosion resistance of the coating. In order to increase understanding of the details of this effect, this work uses X-ray photoelectron spectroscopy (XPS) to study the passive films formed on thermally sprayed coatings (HVOF) and bulk Inconel 625, a commercially available corrosion resistant Ni-Cr-Mo-Nb alloy. Passive films produced by potentiodynamic scanning to 400 mV in 0.5 M sulphuric acid were compared with air-formed films. The poorer corrosion performance of the thermally sprayed coatings was attributed to Ni(OH){sub 2}, which forms a loose, non-adherent and therefore non-protective film. The good corrosion resistance of wrought Inconel 625 is due to formation of Cr, Mo and Nb oxides.

Band alignment of ZnO/multilayer MoS{sub 2} interface determined by x-ray photoelectron spectroscopy

Energy Technology Data Exchange (ETDEWEB)

Liu, Xinke, E-mail: xkliu@szu.edu.cn, E-mail: liuwj@szu.edu.cn; He, Jiazhu; Chen, Le; Li, Kuilong; Jia, Fang; Zeng, Yuxiang; Lu, Youming; Zhu, Deliang; Liu, Wenjun, E-mail: xkliu@szu.edu.cn, E-mail: liuwj@szu.edu.cn [College of Materials Science and Engineering, Nanshan District Key Lab for Biopolymer and Safety Evaluation, Shenzhen University, 3688 Nanhai Ave, Shenzhen 518060 (China); Zhang, Yuan [School of Physics and Electronic Information, Hua Bei Normal University, 100 Dongshan Road, Huai Bei 235000 (China); Liu, Qiang; Yu, Wenjie [State Key Laboratory of Functional Materials for Informatics, Shanghai Institute of Microsystem and Information Technology, CAS, 865 Chang Ning Road, Shanghai 200050 (China); Wu, Jing [Institute of Materials research and Engineering (IMRE), 2 Fusionopolis Way, Innovis, #08-03, 138634 Singapore (Singapore); He, Zhubing [Department of Materials Science and Engineering, South University of Science and Technology of China, 1088 Xueyuan Road, Shenzhen 518055 (China); Ang, Kah-Wee [Department of Electrical and Computer Engineering, National University of Singapore, 4 Engineering Drive 3, 117583 Singapore (Singapore)

2016-08-15

The energy band alignment between ZnO and multilayer (ML)-MoS{sub 2} was characterized using high-resolution x-ray photoelectron spectroscopy. The ZnO film was deposited using an atomic layer deposition tool, and ML-MoS{sub 2} was grown by chemical vapor deposition. A valence band offset (VBO) of 3.32 eV and a conduction band offset (CBO) of 1.12 eV were obtained for the ZnO/ML-MoS{sub 2} interface without any treatment. With CHF{sub 3} plasma treatment, a VBO and a CBO across the ZnO/ML-MoS{sub 2} interface were found to be 3.54 eV and 1.34 eV, respectively. With the CHF{sub 3} plasma treatment, the band alignment of the ZnO/ML-MoS{sub 2} interface has been changed from type II or staggered band alignment to type III or misaligned one, which favors the electron-hole pair separation. The band alignment difference is believed to be dominated by the down-shift in the core level of Zn 2p or the interface dipoles, which is caused by the interfacial layer rich in F.

Thickness determination of thin solid films by angle-resolved X-ray fluorescence spectrometry using monochromatized synchrotron radiation

Science.gov (United States)

Schmitt, W.; Drotbohm, P.; Rothe, J.; Hormes, J.; Ottermann, C. R.; Bange, K.

1995-05-01

Thickness measurements by the method of angle-resolved, self-ratio X-ray fluorescence spectrometry (AR/SR/XFS) have been carried out on thin solid films using monochromatized synchrotron radiation at the Bonn storage ring ELSA. Synchrotron radiation was monochromatized by means of a double-crystal monochromator and fluorescence radiation was detected by a Si(Li) semiconductor detector. The results for sample systems consisting of Au on Si, Cr on SiO2 and TiO2 on alkali-free glass are very satisfactory and agree well with results obtained by other methods.

Synchrotron radiation x-ray photoelectron spectroscopy study on the interface chemistry of high-k PrxAl2-xO3 (x=0-2) dielectrics on TiN for dynamic random access memory applications

Science.gov (United States)

Schroeder, T.; Lupina, G.; Sohal, R.; Lippert, G.; Wenger, Ch.; Seifarth, O.; Tallarida, M.; Schmeisser, D.

2007-07-01

Engineered dielectrics combined with compatible metal electrodes are important materials science approaches to scale three-dimensional trench dynamic random access memory (DRAM) cells. Highly insulating dielectrics with high dielectric constants were engineered in this study on TiN metal electrodes by partly substituting Al in the wide band gap insulator Al2O3 by Pr cations. High quality PrAlO3 metal-insulator-metal capacitors were processed with a dielectric constant of 19, three times higher than in the case of Al2O3 reference cells. As a parasitic low dielectric constant interface layer between PrAlO3 and TiN limits the total performance gain, a systematic nondestructive synchrotron x-ray photoelectron spectroscopy study on the interface chemistry of PrxAl2-xO3 (x =0-2) dielectrics on TiN layers was applied to unveil its chemical origin. The interface layer results from the decreasing chemical reactivity of PrxAl2-xO3 dielectrics with increasing Pr content x to reduce native Ti oxide compounds present on unprotected TiN films. Accordingly, PrAlO3 based DRAM capacitors require strict control of the surface chemistry of the TiN electrode, a parameter furthermore of importance to engineer the band offsets of PrxAl2-xO3/TiN heterojunctions.

Investigation of the surface composition of electrodeposited black chromium by X-ray photoelectron spectroscopy

International Nuclear Information System (INIS)

Survilienė, S.; Češūnienė, A.; Jasulaitienė, V.; Jurevičiūtė, I.

2015-01-01

Highlights: • Black chromium electrodeposited from a Cr(III) bath is composed of oxide, hydroxide and metallic chromium. • Metallic phase is absent in black chromium electrodeposited from a Cr(III) + ZnO bath. • The near-surface layer is rich in hydroxides, whereas oxides of both metals predominate in the depth of the coatings. - Abstract: The paper reviews black chromium electrodeposited from a trivalent chromium bath containing ZnO as a second main component. The chemical compositions of the top layers of the black chromium coatings were studied by the X-ray photoelectron spectroscopy method. The surface of black chromium was found to be almost entirely covered with organic substances. To gain information on the state of each element in the deposit bulk, the layer-by-layer etching of the black chromium surface with argon gas was used. Analysis of XPS spectra has shown that the top layers of black chromium without zinc are composed of various Cr(III) components, organic substances and metallic Cr, whereas metallic Cr is almost absent in black chromium containing some amount of Zn(II) compounds. The ratios of metal/oxide phases were found to be 10/27 and 2/28 for black chromium without and with zinc, respectively. It has been determined that owing to the presence of ZnO in the Cr(III) bath, the percentage of metallic chromium is substantially reduced in black chromium which is quite important for good solar selective characteristics of the coating. The results confirm some of earlier observations and provide new information on the composition of the near-surface layers

Efficient high-resolution X-ray emission spectrometry using synchrotron radiation

International Nuclear Information System (INIS)

Unterumsberger, Rainer

2015-01-01

The aim of the present work is to get access to high-resolution X-Ray Emission Spectrometry (XES) at nanoscaled materials, consisting of light elements and transition metals, by the increase of the sensitivity of a Wavelength-Dispersive Spectrometer (WDS) in the soft X-Ray range. The increase of the sensitivity was achieved by a refocusing of the incident radiation. With the increased sensitivity of the WDS, it was possible to determine the chemical species of different, nominal 100 nm thin titanium oxides. The combination of the refocusing optic and calibrated spectrometer enabled the detection and deconvolution of the L-fluorescence radiation of these nanoscaled titanium oxides. Due to the calibration of the spectrometer, a reliable determination of the transition probabilities of the titanium La- and Ll-fluorescence lines as a function of the chemical state is possible. To the best of my knowledge, the determination of the transition probabilities as a function of the chemical state in the soft X-Ray range has not been investigated yet. The quality of the refocusing was characterized using different diagnostic tools. Vertical full width at half maximum (FWHM) values of the focused beam between 10 μm to 20 μm and horizontal FWHM values between 12 μm and 25 μm could be achieved over an energy range of 180 eV to 1310 eV. Using calibrated photodiodes, it was possible to determine the absolute transmission of the used single bounce monocapillary as well as to monitor the absolute photon flux. By means of the refocusing, it was possible to increase the photon flux by a factor of 4.9 experimentally. The increase of the photon flux enables the analysis of nanoscaled materials with the used spectrometer. This could be shown based on the determination of the lower limit of detection of boron Ka and titanium La. In both cases, the lower limit of detection of 0.4 nm equivalent layer thickness was achieved (about 1.10 -7 g/cm 2 to 2.10 -7 g/cm 2 or 3.10 15 atoms/cm 2 to