首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 15 毫秒
1.
This International Standard describes three methods for measuring the lateral resolution achievable in Auger electron spectrometers and X‐ray photoelectron spectrometers under defined settings. The straight‐edge method is suitable for instruments where the lateral resolution is expected to be larger than 1 µm. The grid method is suitable if the lateral resolution is expected to be less than 1 µm but more than 20 nm. The gold‐island method is suitable for instruments where the lateral resolution is expected to be less than 50 nm. The standard contains three informative annexes that provide illustrative examples of measurements of lateral resolution. Copyright © 2008 John Wiley & Sons, Ltd.  相似文献   

2.
This International Standard specifies a method for evaluating the repeatability and constancy of the intensity scale of X‐ray photoelectron spectrometers, for general analytical purposes, using non‐monochromated Al or Mg X‐rays or monochromated Al X‐rays. It is only applicable to instruments that incorporate an ion gun for sputter cleaning. It is not intended to be a calibration of the intensity/energy response function (Seah MP. J. Electron Spectrosc. 1995; 71: 191; http://www.npl.co.uk/nanoanalysis/a1calib.html [2006]). That calibration may be made by the instrument manufacturer or other organization. The present method provides data to evaluate and confirm the accuracy with which the intensity/energy response function remains constant with instrument usage. Guidance is given to some of the instrument settings that may affect this constancy. Copyright © 2006 John Wiley & Sons, Ltd.  相似文献   

3.
This International Standard specifies a method for evaluating the constancy and repeatability of the intensity scale of Auger electron spectrometers, for general analytical purposes, using an electron gun with a beam energy of 2 keV or greater. It is only applicable to instruments that incorporate an ion gun for sputter cleaning. It is not intended to be a calibration of the intensity/energy response function. 1 , 2 That calibration may be made by the instrument manufacturer or other organization. The present procedure provides data to evaluate and confirm the accuracy with which the intensity/energy response function remains constant with instrument usage. Guidance is given to some of the instrumental settings that may affect this constancy. © Crown Copyright 2006. Reproduced with the permission of the Controller of HMSO.  相似文献   

4.
This International Standard specifies a method for calibrating the kinetic energy scales of Auger electron spectrometers for elemental and chemical‐state analysis at surfaces. It is only applicable to instruments that incorporate an ion gun for sputter cleaning. This International Standard further specifies a method to establish a calibration schedule, to test for the kinetic energy scale linearity at one intermediate energy, to confirm the uncertainty of the scale calibration at one low and one high kinetic energy value, to correct for small drifts of that scale and to define the expanded uncertainty of the calibration of the kinetic energy scale for a confidence level of 95%. This uncertainty includes contributions for behaviours observed in interlaboratory studies but does not cover all of the defects that could occur. This International Standard is not applicable to instruments with kinetic energy scale errors that are significantly non‐linear with energy, to instruments operated at relative resolutions poorer than 0.2% in the constant ΔE/E mode or poorer than 1.5 eV in the constant ΔE mode, to instruments requiring tolerance limits of ±0.05 eV or less or to instruments equipped with an electron gun that cannot be operated in the energy range 5–10 keV. This standard does not provide a full calibration check, which would confirm the energy measured at each addressable point on the energy scale and should be performed according to the manufacturer's recommended procedures. Crown Copyright © 2003. Published by John Wiley & Sons, Ltd.  相似文献   

5.
This International Standard specifies a method for calibrating the kinetic energy scale of Auger electron spectrometers with an uncertainty of 3 eV for general analytical use for identifying elements at surfaces. It is suitable for instruments used in either the direct mode or the differential mode where the resolution is equal to or less than 0.5% and the modulation amplitude for the differential mode, if used, is 2 eV peak to peak. The spectrometer shall be equipped with an inert gas ion gun or other method for sample cleaning and with an electron gun capable of operating at 4 keV or higher beam energy. This International Standard further specifies a calibration schedule. Crown Copyright © 2003. Published by John Wiley & Sons, Ltd.  相似文献   

6.
This International Standard specifies a secondary ion mass spectrometric method using magnetic‐sector or quadrupole mass spectrometers for depth profiling of boron in silicon, and using stylus profilometry or optical interferometry for depth calibration. This method is applicable to single‐crystal, polycrystal or amorphous silicon specimens with boron atomic concentrations between 1 × 1016 and 1 × 1020 atoms cm?3, and to the crater depth of 50 nm or deeper. Optical interferometry is generally applicable to crater depths in the range 0.5–5 µm. Copyright © 2004 John Wiley & Sons, Ltd.  相似文献   

7.
International Standard ISO 19318 specifies the minimum amount of information describing the methods of charge control and charge correction in measurements of core‐level binding energies for insulating specimens by x‐ray photoelectron spectroscopy, which is to be reported with the analytical results. Information is also provided on methods that have been found useful for charge control and charge correction in the measurement of binding energies. Copyright © 2005 John Wiley & Sons, Ltd.  相似文献   

8.
ISO Technical Report 18392 provides the guidance for determining backgrounds in X‐ray photoelectron spectra. The methods of background determination described in this report are applicable for the quantitative evaluation of the spectra of photoelectrons and Auger electrons excited by X‐rays from solid surfaces and surface nanostructures. Copyright © 2006 John Wiley & Sons, Ltd.  相似文献   

9.
This International Standard specifies several methods for measuring the oxide thickness at the surfaces of (100) and (111) silicon wafers as an equivalent thickness of silicon dioxide when measured using X‐ray photoelectron spectroscopy. It is only applicable to flat, polished samples and for instruments that incorporate an Al or Mg X‐ray source, a sample stage that permits defined photoelectron emission angles and a spectrometer with an input lens that may be restricted to less than a 6° cone semiangle. For thermal oxides in the range 1‐ to 8‐nm thickness, using the best method described in this International Standard, uncertainties at a 95% confidence level around 2% may be typical and around 1% at optimum. A simpler method is also given with slightly poorer, but often adequate, uncertainties. Copyright © 2012 Crown copyright.  相似文献   

10.
This International Standard is designed to allow the user to simply assess, on a routine basis, several key parameters of an X‐ray photoelectron spectrometer. It is not intended to provide an exhaustive performance check but instead provides a rapid set of tests that may be conducted frequently. Aspects of instrument behaviour covered by this document include the vacuum, measurements of spectra of conductive or non‐conductive samples and the current state of the X‐ray source. Other important aspects of the instrument performance (e.g. lateral resolution) fall outside the scope of this standard. The standard is intended for use with commercial X‐ray photoelectron spectrometers equipped with a monochromated Al Kα X‐ray source or with a unmonochromated Al or Mg Kα X‐ray source. Copyright © 2012 John Wiley & Sons, Ltd.  相似文献   

11.
ISO/TR 18394 provides guidance for the identification of chemical effects on x‐ray or electron‐excited Auger electron spectra as well as for applications of these effects in chemical characterization of surface/interface layers of solids. In addition to elemental composition, information can be obtained on the chemical state and the surrounding local electronic structure of the atom with the initial core hole from the changes of Auger electron spectra upon the alteration of its local environment. The methods of identification and use of chemical effects on Auger electron spectra, as described in this Technical Report, are very important for accurate quantitative applications of Auger electron spectroscopy. Copyright © 2007 John Wiley & Sons, Ltd.  相似文献   

12.
This international standard specifies chemical methods for the collection of iron and/or nickel from the surface of silicon‐wafer working reference materials by the vapour‐phase decomposition method or the direct acid droplet decomposition method. The determination of the elements collected may be carried out by total‐reflection x‐ray fluorescence spectroscopy, as well as by graphite‐furnace atomic absorption spectroscopy or inductively coupled plasma mass spectroscopy. This international standard applies to iron and/or nickel atomic surface densities from 6 × 109 to 5 × 1011 atoms cm?2. Copyright © 2005 John Wiley & Sons, Ltd.  相似文献   

13.
This article is a brief summary of the ISO Standard 20903. This standard provides information on methods for the measurement of peak intensities in Auger electron and X‐ray photoelectron spectra and on uncertainties of the derived peak areas. It also specifies the necessary information required in a report of analytical results based on such measurements. Published in 2007 by John Wiley & Sons, Ltd.  相似文献   

14.
This international standard specifies the minimum amount of information required for describing the methods of charge control and charge correction in measurements of Auger electron transitions from insulating specimens by electron‐stimulated AES to be reported with the analytical results. Information is provided in an Annex on methods that have been found useful for charge control prior to or during AES analysis. The Annex also includes a summary table of methods or approaches, ordered by simplicity of approach. A similar international standard has been published for XPS (ISO 19318: 2003(E), Surface chemical analysis—XPS—reporting of methods used for charge control and charge correction. Copyright © 2010 John Wiley & Sons, Ltd.  相似文献   

15.
We describe a quantum‐chemical approach for the determination of modes with maximum Raman and Raman optical activity (ROA) intensity by maximizing the intensities with respect to the Raman and Raman optical activity intensity, respectively, which is shown to lead to eigenvalue equations. The intensity‐carrying modes are in general hypothetical modes and do not directly correspond to a certain normal mode in the spectrum. However, they provide information about those molecular distortions leading to intense bands in the spectrum. Modes with maximum Raman intensity are presented for propane‐1,3‐dione, propane‐1,3‐dionate, and Λ‐tris(propane‐1,3‐dionato)cobalt(III). Moreover, the mode with highest ROA intensity is examined for this chiral cobalt complex and also for the (chiral) amino acid L ‐tryptophan. The Raman and ROA high‐intensity modes are an optimal starting guess for intensity‐tracking calculations, in which selectively normal modes with high Raman or ROA intensity are converged. We present the first Raman and ROA intensity‐tracking calculations. These reveal a high potential for large molecules, for which the selective calculation of normal modes with high intensity is desirable in view of the large computational effort required for the calculation of Raman and ROA polarizability property tensors.  相似文献   

16.
ISO Technical Report 19319:2003 contains information on the determination of lateral resolution, analysis area and sample area viewed by the analyser in surface analyses by Auger electron spectroscopy and x‐ray photoelectron spectroscopy. This article provides a brief summary of this information. Copyright © 2004 John Wiley & Sons, Ltd.  相似文献   

17.
The use of visible and UV Fourier transform spectrometers for intensity measurement in emission spectra is described. The intensity ratio between different methods of excitation is a useful aid to term analysis: It can be used to confirm an assignment or to indicate an upper state excitation energy. The ratio may be used as a substitute for other confirming data such as the Zeeman effect or hfs. Examples are given from the analysis of Fe I. Illustrative results on line profiles and on continuum observations in the far UV are also presented.  相似文献   

18.
ISO/TR 19693:2018—Surface chemical analysis—Characterization of functional glass substrates for biosensing applications gives an overview of methods, strategies, and guidance to identify possible sources of problems related to substrates, device production steps (cleaning, activation, and chemical modification), and shelf life (storage conditions and aging). It is particularly relevant for surface chemical analysts characterizing glass‐based biosensors, and developers or quality managers in the biosensing device production community. Based on quantitative and qualitative surface chemical analysis, strategies for identifying the cause of poor performance during device manufacturing can be developed and implemented. A review of measurement capabilities of surface analytical methods is given to assist readers from the biosensing community.  相似文献   

19.
Real‐time nuclear magnetic resonance (NMR) spectroscopy measurements carried out with a bench‐top system installed next to the reactor inside the fume hood of the chemistry laboratory are presented. To test the system for on‐line monitoring, a transfer hydrogenation reaction was studied by continuously pumping the reaction mixture from the reactor to the magnet and back in a closed loop. In addition to improving the time resolution provided by standard sampling methods, the use of such a flow setup eliminates the need for sample preparation. Owing to the progress in terms of field homogeneity and sensitivity now available with compact NMR spectrometers, small molecules dissolved at concentrations on the order of 1 mmol L?1 can be characterized in single‐scan measurements with 1 Hz resolution. Owing to the reduced field strength of compact low‐field systems compared to that of conventional high‐field magnets, the overlap in the spectrum of different NMR signals is a typical situation. The data processing required to obtain concentrations in the presence of signal overlap are discussed in detail, methods such as plain integration and line‐fitting approaches are compared, and the accuracy of each method is determined. The kinetic rates measured for different catalytic concentrations show good agreement with those obtained with gas chromatography as a reference analytical method. Finally, as the measurements are performed under continuous flow conditions, the experimental setup and the flow parameters are optimized to maximize time resolution and signal‐to‐noise ratio.  相似文献   

20.
Hemithioindigo (HTI) photoswitches have a tremendous potential for biological and supramolecular applications due to their absorptions in the visible‐light region in conjunction with ultrafast photoisomerization and high thermal bistability. Rational tailoring of the photophysical properties for a specific application is the key to exploit the full potential of HTIs as photoswitching tools. Herein we use time‐resolved absorption spectroscopy and Hammett analysis to discover an unexpected principal limit to the photoisomerization rate for donor‐substituted HTIs. By using stationary absorption and fluorescence measurements in combination with theoretical investigations, we offer a detailed mechanistic explanation for the observed rate limit. An alternative way of approaching and possibly even exceeding the maximum rate by multiple donor substitution is demonstrated, which give access to the fastest HTI photoswitch reported to date.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号