Analytical Sciences
Online ISSN : 1348-2246
Print ISSN : 0910-6340
ISSN-L : 0910-6340
Volume 26 , Issue 2
Showing 1-26 articles out of 26 articles from the selected issue
Rapid Communications
  • Takeyoshi GOTO, Hitoshi WATARAI
    Type: Rapid Communications
    2010 Volume 26 Issue 2 Pages 135-136
    Published: February 10, 2010
    Released: February 10, 2010
    JOURNALS FREE ACCESS
    The effects of stretching forces on covalently bridged 3-mercaptopropanoic acid molecules between magnetic particles (MPs) and Ag nano-particles (NPs) were studied by surface-enhanced Raman scattering (SERS) spectroscopy. With an exertion of 100 pN per single MP, the intensity ratio of the C-S stretching vibrations for trans-to-gauche conformations was increased from 0.295 ± 0.008 to 0.69 ± 0.09. From the experimental result, it was concluded that the magnetic forces increased the distance between the MP and the Ag NP surface, and induced a shift of the isomerization equilibrium to the trans conformation. The present approach is a new candidate for a dynamic force spectroscopy of conformational equilibria.
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  • Yumi YOSHIDA, Satoshi YAMAGUCHI, Kohji MAEDA
    Type: Rapid Communications
    2010 Volume 26 Issue 2 Pages 137-139
    Published: February 10, 2010
    Released: February 10, 2010
    JOURNALS FREE ACCESS
    An indium tin oxide glass electrode coated with poly(3,4-ethylenedioxythiophene), PEDOT, PEDOT-ITOE, was proposed as an electrode workable as both a reference electrode and a counter one, a reference/counter electrode, in an organic phase and applied to a thin-layer cell of a two-electrode system for voltammetry at the liquid | liquid interface. By oxidizing the PEDOT film by 50% and doping a supporting electrolyte anion in an organic phase into the PEDOT film, a suitable depolarization was realized at the PEDOT | organic phase interface. The partially oxidized PEDOT-ITOE showed a Nerntian response to the supporting electrolyte anion concentration in the organic phase. The electrode potential was stable within ±3 mV for 12 h, and showed a consistent value among the PEDOT-ITOEs prepared under the same procedure (the error range was about 7 mV, n = 8).
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  • Xiangliang NIE, Weibing HU
    Type: Rapid Communications
    2010 Volume 26 Issue 2 Pages 141-142
    Published: February 10, 2010
    Released: February 10, 2010
    JOURNALS FREE ACCESS
    A carbon sphere-modified glass carbon electrode was prepared by employing cyclohexanol as a solvent to disperse the carbon spheres efficiently. The resulting electrode exhibits excellent sensitivity to cadmium(II), and a detection limit of 10−10 mol/L has been obtained, which is one order of magnitude lower than those obtained by other electrodes. Along with immunity from interference of other metal ions, the wide determination range and good linear correlation coefficient would be beneficial to applications of the electrode.
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  • Norio TESHIMA, Daisuke NOGUCHI, Yasutaka JOICHI, Narong LENGHOR, Norik ...
    Type: Rapid Communications
    2010 Volume 26 Issue 2 Pages 143-144
    Published: February 10, 2010
    Released: February 10, 2010
    JOURNALS FREE ACCESS
    A novel concept of simultaneous injection-effective mixing analysis (SIEMA) is proposed, and a SIEMA method applied to the spectrophotometric determination of palladium using a water-soluble chromogenic reagent has been demonstrated. The flow configuration of SIEMA is a hybrid format of flow injection analysis (FIA), sequential injection analysis (SIA) and multicommutation in flow-based analysis. Sample and reagent solutions are aspirated into each holding coil through each solenoid valve by a syringe pump, and then the zones are simultaneously dispensed (injected) into a mixing coil by reversed flow toward a detector through a confluence point. This results in effective mixing and rapid detection with low reagent consumption.
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Reviews
  • Hiroko ARAI, Takashi FUJIKAWA
    Type: Reviews
    2010 Volume 26 Issue 2 Pages 147-154
    Published: February 10, 2010
    Released: February 10, 2010
    JOURNALS FREE ACCESS
    An introductory review is presented on the basis of many-body scattering theory. Some fundamental aspects of photoemission theory are discussed in detail. A few applications are also discussed; photoelectron diffraction, depth distribution function and multi-atom resonant photoemission are also discussed briefly.
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  • Aleksander JABLONSKI
    Type: Reviews
    2010 Volume 26 Issue 2 Pages 155-164
    Published: February 10, 2010
    Released: February 10, 2010
    JOURNALS FREE ACCESS
    It is now well known that elastic photoelectron scattering in the surface region of solids cannot be ignored in the mathematical formalism of quantitative XPS. Elastic collisions may increase or decrease the photoelectron signal intensity, depending on the experimental configuration. Consequently, it is advisable to take into account these effects in calculations of the surface composition. In certain experimental geometries, the photoelectron intensity is practically unaffected by elastic scattering events (configurations defined by the so-called “Master Angle”), and in principle such geometries should be recommended for measurements. Unfortunately, they usually cannot be implemented in typical constructions of spectrometers. In the present paper, different procedures for estimating corrections for elastic scattering events are overviewed. The influence of these correction procedures has been illustrated on examples of AuAgCu and AuAgPdCu alloys. It turned out that elastic photoelectron collisions substantially decrease the signal intensities selected for analysis. However, they are diminished by roughly the same factor. As a consequence, the calculated surface composition is only slightly modified by the correction procedure. This effect may not be of general validity for all solids, and the algorithms for calculating the surface composition should have an option for including any elastic scattering effects. Further efforts are needed to improve the predictive formulas providing corrections for elastic scattering effects.
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  • Takaharu NAGATOMI, Shigeo TANUMA
    Type: Reviews
    2010 Volume 26 Issue 2 Pages 165-176
    Published: February 10, 2010
    Released: February 10, 2010
    JOURNALS FREE ACCESS
    Surface excitations, in addition to bulk excitation, undergone by signal electrons in surface electron spectroscopies, such as Auger electron spectroscopy, and X-ray photoelectron spectroscopy, play an important role in the formation of electron spectra. Those inelastic scattering processes not only induce decay in the peak intensity, but also form background appearing in the lower kinetic energy side of relevant peaks. Information on surface excitation is essential in addition to bulk excitations for the quantification of material surfaces by surface electron spectroscopies, and extensive studies have been devoted to it. In this report, we introduce the basics of the study of surface excitations by reflection electron energy loss spectroscopy (REELS) and elastic peak electron spectroscopy (EPES). The application of several approaches within the schemes of EPES analysis and REELS analysis to the experimental determination of inelastic scattering parameters, such as the surface excitation parameter (SEP), differential SEP (DSEP), inelastic mean free path (IMFP), and dielectric function, are also introduced. Information useful to calculate the values of the IMFP and SEP using predictive equations is provided in Supporting Information as well.
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  • J. ZEMEK
    Type: Reviews
    2010 Volume 26 Issue 2 Pages 177-186
    Published: February 10, 2010
    Released: February 10, 2010
    JOURNALS FREE ACCESS
    This paper reviews work done of the influence of non-ideal surface topography on electron spectral intensities of surface-sensitive electron spectroscopic methods: primarily X-ray induced photoelectron spectroscopy (XPS) and concise Auger electron spectroscopy (AES), electron energy loss spectroscopy in the reflection mode (REELS), and elastic peak electron spectroscopy (EPES). Several attempts to solve the problem are mentioned, where (i) the effect of surface roughness is corrected using a single parameter, (ii) computer simulations based on a model of surface roughness composed of regular geometrical units are used for electron spectral intensity calculations, and finally, (iii) a semi-empirical method based on careful surface mapping of analyzed sample by atomic force microscopy (AFM) is discussed in greater detail. The first approach was found to be rather simple to properly include any complex surface topography. The second technique can help us to understand surface topography related phenomena. The latter method, suitable for arbitrary rough solid surfaces covered by conformal overlayer(s), can be incorporated in current quantitative procedures valid for ideally flat surfaces.
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  • Y. FUKUDA
    Type: Reviews
    2010 Volume 26 Issue 2 Pages 187-197
    Published: February 10, 2010
    Released: February 10, 2010
    JOURNALS FREE ACCESS
    An old surface analytical method, appearance potential spectroscopy (APS), which can probe empty electronic states, is briefly reviewed, since it has an ability to be applied to studying nanostructures. Although the theoretical calculation of the APS spectra including a two-electron process is not much simpler than that of x-ray absorption spectroscopy (XAS) spectra with a one-electron process, measurements of the APS spectra are simpler than those of the XAS ones. A careful interpretation of the spectra would lead to a characteristic and simple surface chemical analysis.
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  • Kazuhiro YOSHIHARA
    Type: Reviews
    2010 Volume 26 Issue 2 Pages 199-202
    Published: February 10, 2010
    Released: February 10, 2010
    JOURNALS FREE ACCESS
    The International Organization for Standardization (ISO) decided to establish a Technical Committee 201 (TC201) on the standardization of surface chemical analysis in 1991. Since then, TC201 has published 38 ISO standards. They concern the vocabulary, instrument specifications, pretreatments of specimen, the procedures for analysis, apparatus alignments, measurement conditions, quantification and reporting formats. In this paper, ISO standards on the calibration of energy and intensity scales of electron spectrometers are briefly introduced. Common Data Processing System is the software for assisting in using ISO standards, and its functions for the calibration of energy and intensity scales are also introduced.
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Original Papers
  • Mineharu SUZUKI, Nobuaki URUSHIHARA, Noriaki SANADA, Dennis F. PAUL, S ...
    Type: Original Papers
    2010 Volume 26 Issue 2 Pages 203-208
    Published: February 10, 2010
    Released: February 10, 2010
    JOURNALS FREE ACCESS
    Cross-sections of GaAs/AlAs thin films prepared by cleavage of MBE-grown superlattices have been analyzed with Auger electron spectroscopy with a spatial resolution of 6 nm. Elemental distributions of Ga, Al, and As were clearly distinguished in line analysis as well as in two dimensional mapping for 50, 20, and 10 nm thin film structures. We have found an oscillation of Al KLL peak position between the two values while the peak positions of Ga LMM and As LMM remain constant. The origin of the Al KLL peak shift is a primary electron beam induced reduction of oxidized Al atoms formed during specimen preparation. The Auger spectra of Al oxide are generated by scattered electrons at regions with small amounts of electron dose, corresponding to AlAs areas further than 10 to 25 nm from the primary beam. The intensity of the Al KLL peaks excited by scattered electrons from the 25 kV primary electron beam is about 10% of the Ga LMM peak intensity originating from the GaAs stripe.
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  • Jirí PAVLUCH, Ludomir ZOMMER, Karel MAŠEK, Tomá&s ...
    Type: Original Papers
    2010 Volume 26 Issue 2 Pages 209-215
    Published: February 10, 2010
    Released: February 10, 2010
    JOURNALS FREE ACCESS
    Non-evaporable Ti-Zr-V ternary getters (NEGs) were studied by means of excitation energy resolved photoelectron spectroscopy (ERXPS). We attempted a quantitative study of the in-depth redistribution of the NEG components during activation. The samples were prepared ex-situ by DC magnetron sputtering on a stainless-steel substrate. The ERXPS measurements were carried out at two incident photoelectron beam angles at energies of 110, 195, 251, 312, 397 and 641 eV. Besides these photon energies, also standard X-ray photoelectron spectroscopy (XPS) was used at a photon energy of 1254 eV. We accumulated Ti 3s, Ti 3p, Ti 3d, V 3s, V 3p, V 3d, Zr 3p, Zr 3d, Zr 4s, Zr 4p, Zr 4d, C 1s, O 1s and O 2s photoelectron peak intensities as functions of the kinetic energies given to them. Under simplifying assumptions, Monte-Carlo calculations of the activated sample concentration profiles were performed to fit the measured spectra intensities. The results proved an in-depth redistribution of the components during the activation process. This way we also contributed to a further development of non-destructive depth profiling by electron spectroscopy techniques.
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  • Beata LESIAK, Josef ZEMEK, Jana HOUDKOVA, Alexander KROMKA, Adam J&Oac ...
    Type: Original Papers
    2010 Volume 26 Issue 2 Pages 217-222
    Published: February 10, 2010
    Released: February 10, 2010
    JOURNALS FREE ACCESS
    The X-ray excited Auger electron spectroscopy (XAES), X-ray photoelectron spectroscopy (XPS) and elastic peak electron spectroscopy (EPES) methods were applied in investigating samples of nanocrystalline diamond and highly oriented pyrolytic graphite of various C sp2/sp3 ratios, crystallinity conditions and grain sizes. The composition at the surface was estimated from the XPS. The C sp2/sp3 ratio was evaluated from the width of the XAES first derivative C KLL spectra and from fitting of XPS C 1s spectra into components. The pattern recognition (PR) method applied for analyzing the spectra line shapes exhibited high accuracy in distinguishing different carbon materials. The PR method was found to be a potentially useful approach for identification, especially important for technological applications in fields of materials engineering and for controlling the chemical reaction products during synthesis.
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  • Kenji KIMURA, Kaoru NAKAJIMA, Thierry CONARD, Wilfried VANDERVORST, An ...
    Type: Original Papers
    2010 Volume 26 Issue 2 Pages 223-226
    Published: February 10, 2010
    Released: February 10, 2010
    JOURNALS FREE ACCESS
    Composition depth profiling of HfO2 (2.5 nm)/SiON (1.6 nm)/Si(001) was performed by three diffetent analytical techniques: high-resolution Rutherford backscattering spectroscopy (HRBS), angle-resolved X-ray photoelectron spectroscopy (AR-XPS) and high-resolution elastic recoil detection (HR-ERD). By comparing these results we found the following: (1) HRBS generally provides accurate depth profiles. However, care must be taken in backgroud subtraction for depth profiling of light elements. (2) In the standard AR-XPS analysis, a simple exponential formula is often used to calculate the photoelectron escape probability. This simple formula, however, cannot be used for the precise depth profiling. (2) Although HR-ERD is the most reliable technique for the depth profiling of light elements, it may suffer from multiple scattering, which deteriorates the depth resolution, and also may cause a large background.
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  • Masaaki KOBATA, Igor PÍŠ, Hideo IWAI, Hiromichi YAMAZUI, ...
    Type: Original Papers
    2010 Volume 26 Issue 2 Pages 227-232
    Published: February 10, 2010
    Released: February 10, 2010
    JOURNALS FREE ACCESS
    This article reports development of a practical laboratory hard X-ray photoelectron spectroscopy (HXPS) system by combining a focused monochromatic Cr Kα X-ray source, a wide angle acceptance objective lens and a high kinetic energy electron analyzer. The Cr Kα source consists of a Cr target, a 15 kV focused electron gun, and a compact bent crystal monochromator. The X-ray spot size is variable from 10 μm (1.25 W) to 200 μm (50 W). A wide acceptance angle objective lens is installed in front of a hemispherical analyzer. The total resolution of 0.53 eV was obtained by Au Fermi-edge measurements. Angle acceptance of ±35° with angle resolution of 0.5° was achieved by measuring Au 3d5/2 peak through a hemicylinder multi-slit on an Au thin strip, in angle resolution mode. As the examples, silicon based multilayer thin films were used for showing the possibilities of deeper (larger) detection depth with the designed system.
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  • Shinjiro HAYAKAWA, Aya TANAKA, Takeshi HIROKAWA
    Type: Original Papers
    2010 Volume 26 Issue 2 Pages 233-237
    Published: February 10, 2010
    Released: February 10, 2010
    JOURNALS FREE ACCESS
    The averaged attenuation length of emitted electrons with the conversion electron yield (CEY) method was evaluated for Ni films with the x-rays below and above the Ni K absorption edge. The evaluated attenuation length was 13.1 nm with the x-rays below the Ni K absorption edge, and it became 24.0 nm with the contribution of Ni KLL Auger electrons that had the attenuation length of 78.1 nm. The probing depth of the CEY measurements are determined both the penetration depth of x-rays and the attenuation length of emitted electrons, and the modification of the probing depth was investigated with the grazing incidence condition. The glancing angle dependence of the CEY was compared with the model calculation, and the probing depth of around 1.6 nm was realized under the total reflection condition. The probing depth was controlled from 1.6 nm to the attenuation length by changing the glancing angle.
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  • A. JABLONSKI, J. ZEMEK
    Type: Original Papers
    2010 Volume 26 Issue 2 Pages 239-246
    Published: February 10, 2010
    Released: February 10, 2010
    JOURNALS FREE ACCESS
    The quantification of results of electron spectroscopies, AES and XPS, requires knowledge of the inelastic mean free path (IMFP) of signal electrons in solids. This parameter determines the surface sensitivity of both techniques. There are two methods of determining the IMFPs that provide these parameters in agreement with the definition: (i) calculations based on the experimental optical data, and (ii) calculations based on measurements of the electron elastic backscattering intensity. The latter method requires the use of some reference material for which the IMFP is known. In 1999, an extensive analysis of the published IMFPs has been performed; the results indicated that there is a very good agreement between the calculated and measured IMFPs for four elemental solids: Ni, Cu, Ag and Au. The averaged IMFPs for these elements are known under the name of the recommended IMFPs. However, no preference among these four elements has been established. In the present work, an attempt is made to select an element for which the recommended IMFPs result in the best agreement between the calculated and measured intensities of elastic electron backscattering. For this purpose, the elastic backscattering intensity has been measured at eight electron energies varying from 200 to 1500 eV. At each energy, the intensity was measured over a wide range of emission angles from 35° to 74°. The experiments were accompanied with Monte Carlo calculations of the elastic backscattering probability for the same energies and experimental configurations. It has been found, from comparison, that the best agreement is observed for Au, and this element is thus recommended as the reference material. It has been shown that the shape of the emission angle dependence of the elastic backscattering intensity is noticeably influenced by the surface energy losses.
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  • Sei FUKUSHIMA, Satoshi OTA
    Type: Original Papers
    2010 Volume 26 Issue 2 Pages 247-251
    Published: February 10, 2010
    Released: February 10, 2010
    JOURNALS FREE ACCESS
    The Auger process on shallow levels, caused by the Auger process in deeper levels, called “cascade Auger process”, were studied. From the measurement result, the cascade Auger process can be clearly observed by the excitation of X-ray tubes instead of a synchrotron radiation source. Applying a theoretical investigation with a cluster calculation to the spectral change of the Ag MVI,VVV peak, it was theoretically shown that the cascade Auger process should be correct for explaining the observed spectral change. In addition, it pointed out the existence of a cascade Auger process caused by holes left by the Coster-Kronig process on deeper levels. For the first time the measurement of this process was successful using X-ray tube excitation.
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  • Sei FUKUSHIMA, Satoshi OTA
    Type: Original Papers
    2010 Volume 26 Issue 2 Pages 253-257
    Published: February 10, 2010
    Released: February 10, 2010
    JOURNALS FREE ACCESS
    The investigations of Si 1s and 2p photoelectron spectra of a poly-Si plate with natural oxide layers based on high energy excitation using X-ray tubes with three kinds of target (Mg Kα, Zr Lα and Ag Lα) and on the theoretical calculations using DV-Xα were presented. From the comparison between the shift values of Si 1s and 2p corresponding with the metal and oxide, it was found that 1s shift is larger than 2p shift. From the discussion on the cluster calculation, the data revealed that the direction of chemical shift is dominated by the change of the population of 3s/3p or 3d independently.
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  • Yoichiro FURUKAWA, Manabu IWASAKI, Akihiro TANAKA
    Type: Original Papers
    2010 Volume 26 Issue 2 Pages 259-265
    Published: February 10, 2010
    Released: February 10, 2010
    JOURNALS FREE ACCESS
    The purpose of this paper is to propose a statistical method for determining minimum detectable values in a pulse-counting measurements. The output of x-ray, electron and ion-spectroscopy detectors is a series of pulses that vary in their arrival frequency according to a Poisson distribution. The analysis presented here relates this to a Normal distribution, making it consistent with the standards and methodology recommended by IUPAC and in the ISO 11843 series of international standards. The theory and limitations of doing this are presented using two types of approximations: a Simple approximation and a Square Root approximation. The variance, critical values of the response variables, capability of detection criteria and the minimum detectable values are then defined. Finally, the validity of the approximations is checked using experimental data. It is concluded that the methodology is accurate enough for practical use.
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  • Alberto HERRERA-GOMEZ, Yongjian SUN, Francisco-Servando AGUIRRE-TOSTAD ...
    Type: Original Papers
    2010 Volume 26 Issue 2 Pages 267-272
    Published: February 10, 2010
    Released: February 10, 2010
    JOURNALS FREE ACCESS
    The structure of 3 nm and 15 nm diamond-like carbon films, grown on Si(001) by filtered cathodic arc, was studied by angle-resolved X-ray photoelectron spectroscopy (ARXPS) and transmission electron microscopy (TEM). The ARXPS data was deconvolved by employing simultaneous-fitting, which allowed for a clear deconvolution of the Si 2p and C 1s spectra into their different chemical contributions. An analysis of the take-off angle dependence of the peak intensities allowed for an independent identification of the physical origin of the chemical species. It was shown that the C 1s peak at 283.3 eV and the Si 2p peak at 99.6 eV correspond to SiC, and that the C/Si interface of the 3 nm film consists of a stoichiometric ∼1 nm SiC layer. To quantify the sp3-sp2 ratio it was necessary to take into account not only their associated C 1s XPS-peak intensities, but also their take-off angle dependence. The thickness of the films obtained through ARXPS closely agrees with cross-sectional TEM images.
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  • Naoto KAMEDA, Tetsuya NISHIGUCHI, Yoshiki MORIKAWA, Mitsuru KEKURA, Ke ...
    Type: Original Papers
    2010 Volume 26 Issue 2 Pages 273-276
    Published: February 10, 2010
    Released: February 10, 2010
    JOURNALS FREE ACCESS
    Using ultraviolet (UV)-excited ozone gas, we prepared high-quality SiO2 films that can be used as gate dielectric films on poly-silicon or silicon wafers without sample heating. The UV-excited ozone gas was generated by UV irradiation of highly concentrated ozone gas. During the UV-excited ozone process, UV light irradiates the sample surface directly through the ozone gas. Then, the temperature at the sample surface is increased by UV-light absorption at the surface. Estimation of this surface temperature is important for understanding the oxidation mechanism. We estimated the surface temperature obtained during UV irradiation to be about 300°C by investigating the temperature dependence of the oxidation rate for oxygen gas. We have previously determined that almost no thermal decomposition of ozone gas occurs at this temperature, and that oxygen gas does not oxidize the Si substrate. Therefore, we concluded that the only oxidation species in the UV-excited ozone process is UV-excited ozone O(1D).
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  • Tatsunori TOCHIO, Shusuke SAKAKURA, Hirofumi OOHASHI, Hirohisa MIZOTA, ...
    Type: Original Papers
    2010 Volume 26 Issue 2 Pages 277-279
    Published: February 10, 2010
    Released: February 10, 2010
    JOURNALS FREE ACCESS
    X-ray fluorescence analysis using Cr Kα spectra was applied to the determination of the mixing ratio of Cr6+ to (Cr6+ + Cr3+) in several mixtures of K2CrO4 and Cr2O3. Because the powder of K2CrO4 contained large particles that were more than 50 μm in diameter, it was ground between a pestle and a mortar for about 8 h. The coarse particles still remaining were removed by using a sieve with 325-mesh (44 μm) in order to reduce the difference in absorption effects between emissions from Cr6+ and those from Cr3+. The mixing ratio, K2CrO4/(K2CrO4 + Cr2O3), of the five mixtures investigated is 0.50, 0.40, 0.20, 0.10, and 0.05 in weight, respectively. Each spectrum obtained was analyzed by decomposing it into two reference spectra, those of the two pure materials, K2CrO4 and Cr2O3, with a constant background. The results for the mixtures containing K2CrO4 of more than 20 wt% are that the relative deviation from the true value is less than ∼5%. On the other hand, when the content of K2CrO4 decreases to less than 10 wt%, the relative deviation gets so large as 20 – 25%. The error coming from a peak separation of spectrum involved in our results were estimated by applying our method to five sets of data for each mixture computationally generated, taking into account the uncertainty in total counts of real measurements.
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