共查询到20条相似文献,搜索用时 46 毫秒
1.
The grazing emission X-ray fluorescence (GEXRF) technique was applied to the analysis of different Al films, with nominal thicknesses in the range of 1 nm to 150 nm, on Si wafers. In GEXRF the sample volume from which the fluorescence intensity is detected is restricted to a near-surface region whose thickness can be tuned by varying the observation angle. This is possible because of the refraction of the fluorescence X-rays and the quite long emission paths within the probed sample. By recording the X-ray fluorescence signal for different shallow emission angles, defined relatively to the flat, smooth sample surface, the deposited Al surface layers of the different samples could be well characterized in terms of layer thickness, layer density, oxidation and surface roughness. The advantages offered by synchrotron radiation and the employed wavelength-dispersive detection setup were profited from. The GEXRF results retrieved were confirmed by complementary measurements. The experimental setup, the principles and advantages of GEXRF and the analysis of the recorded angular intensity profiles will be discussed in details. 相似文献
2.
B. Hołyńska Mariusz Olko Beata Ostachowicz Jerzy Ostachowicz Dariusz Węgrzynek Martine Claes Rene Van Grieken Pieter de Bokx Peter Kump Marijan Necemer 《Analytical and bioanalytical chemistry》1998,362(3):294-298
An intercomparison survey has been carried out in order to evaluate the performance of two related X-ray fluorescence techniques as compared to the achievements of several other analytical techniques applied for trace elements determination in drinking water. A relatively new technique, total reflection X-ray fluorescence (TXRF) and a novel related technique, grazing emission X-ray fluorescence (GEXRF) have been used for the analysis of a mineral water sample. The concentrations of the following elements have been determined: Na, Mg, K, Ca, Ni, Cu, Zn and Sr. The mineral water sample has also been analyzed by a number of other analytical techniques, routinely utilized in drinking water quality control. The analyses were performed in eleven laboratories which reported 286 individual determinations producing 75 laboratory means. From the obtained results, it can be concluded that the TXRF technique is suitable for a direct determination of heavy elements in drinking water (above potassium, Z = 19). This technique can compete with other analytical techniques routinely used in water quality monitoring. First results obtained with GEXRF spectrometry show that this technique can be successfully applied for the determination of low-Z elements in drinking water. However, results for sodium and magnesium were systematically too low, indicating that modifications of the quantification procedure may be required to improve the accuracy of determination for these light elements. 相似文献
3.
《Spectrochimica Acta Part B: Atomic Spectroscopy》1997,52(7):829-840
In grazing-emission X-ray fluorescence spectrometry (GEXRF), the sample is irradiated at approximately normal incidence, and only that part of the fluorescence radiation is detected that is emitted at grazing angles. This configuration allows the use of wavelength-dispersive detection. This type of detection has the advantages of substantially better energy resolution at longer wavelengths (light elements, L and M lines of heavier elements) and a much larger dynamic range than the energy-dispersive detectors currently used in grazing X-ray techniques. Typical examples are presented of applications that are made possible by this new technique. 相似文献
4.
B. Hoyska Mariusz Olko Beata Ostachowicz Jerzy Ostachowicz Dariusz Wgrzynek Martine Claes Rene Van Grieken Pieter de Bokx Peter Kump Marijan Necemer 《Fresenius' Journal of Analytical Chemistry》1998,362(3):294-298
An intercomparison survey has been carried out in order to evaluate the performance of two related X-ray fluorescence techniques
as compared to the achievements of several other analytical techniques applied for trace elements determination in drinking
water. A relatively new technique, total reflection X-ray fluorescence (TXRF) and a novel related technique, grazing emission
X-ray fluorescence (GEXRF) have been used for the analysis of a mineral water sample. The concentrations of the following
elements have been determined: Na, Mg, K, Ca, Ni, Cu, Zn and Sr. The mineral water sample has also been analyzed by a number
of other analytical techniques, routinely utilized in drinking water quality control. The analyses were performed in eleven
laboratories which reported 286 individual determinations producing 75 laboratory means. From the obtained results, it can
be concluded that the TXRF technique is suitable for a direct determination of heavy elements in drinking water (above potassium,
Z = 19). This technique can compete with other analytical techniques routinely used in water quality monitoring. First results
obtained with GEXRF spectrometry show that this technique can be successfully applied for the determination of low-Z elements
in drinking water. However, results for sodium and magnesium were systematically too low, indicating that modifications of
the quantification procedure may be required to improve the accuracy of determination for these light elements.
Received: 5 January 1998 / Revised: 17 February 1998 / Accepted: 18 February 1998 相似文献
5.
Y. Kayser D. Banaś W. Cao J.-Cl. Dousse J. Hoszowska P. Jagodziński M. Kavčič A. Kubala-Kukuś S. Nowak M. Pajek J. Szlachetko 《Spectrochimica Acta Part B: Atomic Spectroscopy》2010
The synchrotron radiation based high-resolution grazing emission X-ray fluorescence (GEXRF) technique was used to extract the distribution of Al ions implanted with a dose of 1016 atoms/cm2 in Si wafers with energies ranging between 1 and 100 keV. The depth distributions of the implanted ions were deduced from the measured angular profiles of the Al-Kα X-ray fluorescence line with nanometer-scale precision. The experimental results were compared to theoretical predictions of the depth distributions resulting from ion implantation. A good agreement between experiment and theory was found which proved that the presented high-resolution grazing emission X-ray fluorescence technique is well suited to perform depth profiling measurements of impurities located within the extinction depth, provided the overall shape of the distribution can be assumed a priori. 相似文献
6.
This review describes recent tendencies for metal-binding and metalloprotein analysis, emphasizing metal quantification in proteins through X-ray, atomic absorption, mass spectrometric techniques, and others. Hyphenated techniques such as capillary electrophoresis-synchrotron radiation X-ray fluorescence (CE-SRXRF), laser ablation-inductively coupled plasma-mass spectrometry (LA-ICP-MS), matrix-assisted laser desorption/ionisation-time-of-flight mass spectrometry (MALDI-TOF-MS), etc. are also presented. As protein separation techniques electrophoresis (mainly sodium dodecyl sulphate-polyacrylamide gel electrophoresis, SDS-PAGE), capillary electrophoresis (CE) and high-performance liquid chromatography (HPLC) are indicated, due to their inherent sensitivity, resolution and/or easy implementation. Latest challenges in metallomics are also commented. 相似文献
7.
N.N. Mirashi Sangita DharaS. Sanjay Kumar Satyajeet ChaudhuryN.L. Misra S.K. Aggarwal 《Spectrochimica Acta Part B: Atomic Spectroscopy》2010
Energy dispersive X-ray fluorescence studies on determination of thorium (in the range of 7 to 137 mg/mL) in phosphoric acid solutions obtained by dissolution of thoria in autoclave were made. Fixed amounts of Y internal standard solutions, after dilution with equal amount of phosphoric acid, were added to the calibration as well as sample solutions. Solution aliquots of approximately 2–5 µL were deposited on thick absorbent sheets to absorb the solutions and the sheets were presented for energy dispersive X-ray fluorescence measurements. A calibration plot was made between intensity ratios (Th Lα/Y Kα) against respective amounts of thorium in the calibration solutions. Thorium amounts in phosphoric acid samples were determined using their energy dispersive X-ray fluorescence spectra and the above calibration plot. The energy dispersive X-ray fluorescence results, thus obtained, were compared with the corresponding gamma ray spectrometry results and were found to be within average deviation of 2.6% from the respective gamma ray spectrometry values. The average precision obtained in energy dispersive X-ray fluorescence determinations was found to be 4% (1σ). The energy dispersive X-ray fluorescence method has an advantage over gamma ray spectrometry for thorium determination as the amount of sample required and measurement time is far less compared to that required in gamma ray spectrometry. 相似文献
8.
C. Horntrich P. Kregsamer P. Wobrauschek C. Streli 《Spectrochimica Acta Part B: Atomic Spectroscopy》2011,66(11-12):815-821
Total Reflection X-ray Fluorescence analysis (TXRF) is widely used in semiconductor industry for the analysis of silicon wafer surfaces. Typically an external standard is used for the calibration of the spectrometer. This is sensitive to errors in quantification. For small sample amounts the thin film approximation is valid, absorption effects of the exciting and the detected radiation are neglected and the relation between sample amount and fluorescence intensity is linear. For higher total sample amounts deviations from linearity have been observed (saturation effect). These deviations are one of the difficulties for external standard quantification.A theoretical determination of the ideal TXRF sample shape is content of the presented work with the aim to improve the calibration process and therefore the quantification.The fluorescence intensity emitted by different theoretical sample shapes was calculated, whereby several parameters have been varied (excitation energy, density, diameter/height ratio of the sample). It was investigated which sample shape leads to the highest fluorescence intensity and exhibits the lowest saturation effect. The comparison of the different sample shapes showed that the ring shape matches the ideal TXRF sample shape best. 相似文献
9.
Horntrich C Smolek S Maderitsch A Simon R Kregsamer P Streli C 《Analytical and bioanalytical chemistry》2011,400(8):2649-2654
Total reflection X-ray fluorescence analysis (TXRF) offers a nondestructive qualitative and quantitative analysis of trace
elements. Due to its outstanding properties TXRF is widely used in the semiconductor industry for the analysis of silicon
wafer surfaces and in the chemical analysis of liquid samples. Two problems occur in quantification: the large statistical
uncertainty in wafer surface analysis and the validity of using an internal standard in chemical analysis. In general TXRF
is known to allow for linear calibration. For small sample amounts (low nanogram (ng) region) the thin film approximation
is valid neglecting absorption effects of the exciting and the detected radiation. For higher total amounts of samples deviations
from the linear relation between fluorescence intensity and sample amount can be observed. This could be caused by the sample
itself because inhomogeneities and different sample shapes can lead to differences of the emitted fluorescence intensities
and high statistical errors. The aim of the study was to investigate the elemental distribution inside a sample. Single and
multi-element samples were investigated with Synchrotron-radiation-induced micro X-ray Fluorescence Analysis (SR-μ-XRF) and
with an optical microscope. It could be proven that the microscope images are all based on the investigated elements. This
allows the determination of the sample shape and potential inhomogeneities using only light microscope images. For the multi-element
samples, it was furthermore shown that the elemental distribution inside the samples is homogeneous. This justifies internal
standard quantification. 相似文献
10.
Timo Wolff Wolfgang Malzer Ioanna Mantouvalou Oliver Hahn Birgit Kanngießer 《Spectrochimica Acta Part B: Atomic Spectroscopy》2011,66(2):170-178
Fundamental parameter based quantification of X-ray fluorescence (XRF) measurement data requires an accurate knowledge of the spectrometer parameters, including the spectral distribution of the excitation radiation. In case of micro-XRF where a polycapillary optic is utilized in the excitation channel this distribution is changed due to the transmission properties of the lens. A new calibration procedure, based on fluorescence data of thin standard samples, was developed to determine the excitation spectrum, i.e., the product of the X-ray tube spectrum and the transmission of the used X-ray optic of a micro-XRF setup. The calibration result was validated by the quantitative analyses of certified multi-element reference standards and shows uncertainties in the order of 2% for main components, 10% for minor elements and 25% for trace elements. The influence of secondary order effects like Coster-Kronig transitions and cascade effects is analyzed and the accuracy of fundamental parameters in common databases is discussed. 相似文献
11.
《Spectrochimica Acta Part B: Atomic Spectroscopy》1999,54(13):1881-1888
Ni ultra-thin films sandwiched with carbon thin films of different thickness are measured by a laboratory grazing-emission X-ray fluorescence instrument. The Ni Kα intensity of the Ni ultra-thin film sandwiched with carbon layers is three times enhanced in comparison with the Ni ultra-thin film without carbon layers. In addition, oscillations caused by interference effects of directly observed X-ray beams and the reflected X-ray beams on the surface of the Pt substrate, are clearly observed. The periods of the oscillations depends on the thickness of the carbon layer, that is, the position of the Ni layer. Therefore, the thickness of the carbon layer can be estimated. 相似文献
12.
Paula P. Bachelor David V. Jordan Warren W. Harper Bret D. Cannon Erin C. Finn 《Journal of Radioanalytical and Nuclear Chemistry》2009,282(3):873-876
Nitrogen fluorescence induced by radiation can be used to detect the presence of radioactive contamination in the environment.
Contamination quantification from the fluorescence signal requires: the source’s effective alpha spectrum; the specific radiation
quantum fluorescence efficiency; optical attenuation length in air of the fluorescence signal; the absolute throughput and
quantum efficiency of the optical instrumentation; calibration of the instrumentation; and radiation transport modeling of
the “effective” array exposure rate given the alpha particle spectrum. Field testing conducted on optical instrumentation
measured the nitrogen fluorescence yield generated by 241Am alpha emissions. Laboratory studies of 241Am via alpha spectrometry determined whether the presence of solids on source surfaces produced sufficient self-absorption
to decrease fluorescence. Results from the laboratory studies provided correction to the effective alpha-source activity values
in a model of the earlier optical-sensor field measurements, and determined the air fluorescence efficiency of alpha particles
generated by the 241Am sources used in the field experiments. 相似文献
13.
14.
《Spectrochimica Acta Part B: Atomic Spectroscopy》2005,60(4):505-510
Monochromatized synchrotron radiation of the electron storage ring BESSY II has been used for the non-destructive thickness determination of nanolayered materials by two different methods. The aim of these investigations was the comparison of completely reference-free fundamental parameter-based X-ray fluorescence analysis with X-ray reflectometry to validate the quantification of X-ray fluorescence analysis as an absolute method. For this purpose, Cu and Ni layers with a thickness varying between 5 nm and 50 nm as well as double layers of both metals deposited on Si have been studied. In X-ray reflectometry characterization experiments, the tunability of the photon energy allows the determination of not only the total layer thickness but also the individual layer thicknesses of the Cu/Ni double-layer systems. Reference-free X-ray fluorescence analysis involves both the fundamental parameter approach and the knowledge of all relevant experimental parameters obtained by instrumentation calibrated absolutely.The layer thickness determined by both methods agreed within their combined uncertainties. In view of the limits of X-ray reflectometry for very thin layers, laterally inhomogeneous samples, and multi-elemental layer compositions, reference-free X-ray fluorescence analysis offers the potential for the thickness determination of such samples. 相似文献
15.
N. I. Mashin E. A. Krylov E. A. Chernyaeva A. V. Ershov E. O. Zimina 《Journal of Analytical Chemistry》2017,72(11):1167-1171
A method is proposed for the determination of mass absorption coefficient in the analysis of two-layer thin-film V/Cr and Cr/V systems on Polikor substrates by X-ray fluorescence spectrometry. Simply fabricated and unified film layers formed by applying vanadium and chromium on polymer film substrates are used. Correction coefficients taking into account the attenuation of primary radiation of X-ray tube and analytical line of an element from the lower layer in the upper layer are calculated. 相似文献
16.
Valadas S Candeias A Mir?o J Tavares D Coroado J Simon R Silva AS Gil M Guilherme A Carvalho ML 《Microscopy and microanalysis》2011,17(5):702-709
In this work, we present the results of an analytical method developed for detailed pigment identification, stratigraphy, and degradation of the paint layers of mural paintings applied in the study of the 17th century frescoes from the Misericordia Church of Odemira (Southwest Portugal). In situ X-ray fluorescence spectrometry analyses were performed on three panels of the mural paintings and complemented by colorimetric measurements. The different color areas were also sampled as microfragments (approx. 1 mm2) that were studied as taken or mounted in epoxy resin to expose the different paint layers. The microfragments of paint layers and their cross sections were characterized by optical microscopy and scanning electron microscopy coupled with energy dispersive X-ray spectrometry. Furthermore, elemental analysis was obtained with spatially resolved confocal synchrotron radiation μ-X-ray fluorescence spectrometry performed at ANKA synchrotron FLUO beamline. Occasionally, phase analysis by μ-X-ray diffraction was also performed. Results from the different techniques allowed pigment identification and, in some cases, the evaluation of color changes due to degradation processes and, considering the Southern Portugal geology, the identification of their possible provenance. The pigments used were essentially yellow, brown and red ochres, smalt blue, copper green, and black earths, probably from local sources. 相似文献
17.
18.
This paper describes an analytical procedure for determining the stoichiometry of BaxSr1-xTiO3 perovskite layers using inductively coupled plasma mass spectrometry (ICP-MS). The analytical results of mass spectrometry measurements are compared to those of X-ray fluorescence analysis (XRF). The performance and the limits of solid-state mass spectrometry analytical methods for the surface analysis of thin BaxSr1-xTiO3 perovskite layers sputtered neutral mass spectrometry (SNMS)--are investigated and discussed. 相似文献
19.
Shinichi Suzuki Yasuhiro Suzuki Hikoto Ohta Masaaki Kasamatsu Toshio Nakanishi 《Analytical sciences》2005,21(7):775-778
Thirteen arsenous acid samples of known origins and refining methods were collected. Each sample was subjected to quantitative analysis of any impurity elements present using synchrotron radiation X-ray fluorescence spectrometry (SR-XRF) and inductively coupled plasma-atomic emission spectrometry (ICP-AES). The trace elements selected were Sn, Sb and Bi for the reasons that they were considered not to be changed by their circumstances and that they showed high sensitivity to SR-XRF. These results obtained by both methods were compared and the correlation between these two methods was determined. The quantification of trace impurities obtained by SR-XRF using As as an internal standard showed good agreement with the results obtained by ICP-AES. The discrimination of refining method became possible by the comparison of these impurities' contents measured with non-destructive SR-XRF using several arsenous acid particles. 相似文献
20.
《Spectrochimica Acta Part B: Atomic Spectroscopy》1997,52(7):881-886
Total-reflection X-ray fluorescence (TXRF) is widely used for the control of metallic contamination caused by surface preparation processes and silicon materials. At least three companies supply a variety of TXRF systems to the silicon integrated circuit (IC) community, and local calibration of these systems is required for their day to day operation. Differences in local calibration methods have become an issue in the exchange of information between IC manufacturers' different FABs (Fabrication Facility) and also between silicon suppliers and IC FABs. The question arises whether a universal set of fluorescence yield curves can be used by these different systems to scale system sensitivity from a single element calibration for calculation of elemental concentrations. This is emphasized by the variety of experimental conditions that are reported for TXRF data (e.g. different angles of incidence for the same X-ray source, different X-ray sources, etc.). It appears that an instrumental factor is required. We believe that heavy ion backscattering spectrometry (HIBS) provides a fundamental method of calibrating TXRF reference materials, and can be used in calculating this instrumental factor. In this paper we briefly describe the HIBS system at the Sandia National Laboratories HIBS User Facility and its application to the calibration of TXRF reference materials. We will compare HIBS and TXRF mapping capabilities and discuss the issues associated with the restrictions of some older TXRF sample stages. We will also discuss Motorola's cross-calibration of several TXRF systems using different elements as references. 相似文献