Analysis of apatite crystals and their fluid inclusions by synchrotron radiation X-ray flourescence microprobe

Chemical composition analysis of apatites and their fluid inclusions from Yu'erya granite was carried out by synchrotron radiation X-ray fluorescence (SRXRF) microprobe. The result shows that all these apatite crystals have a similar chemical signature, with Ca, P, Cl, Mn, Fe, K, S, La, Ce, Pr, Nd, Sm, Eu, Gd, Dy, Er, Yb, Lu, Sr, Y, Zr, U, Th, etc. The rare earth elements chondrite-normalized pattern indicates that these apatites are derived from S-type granite. It is shown by the SRXRF analysis that Zn, Cu and Cl are main components of fluid inclusions in apatites. It is the first time that SRXRF analysis is successfully applied in determination of composition of single fluid inclusions in apatite crystals. This technique was proved to be suitable for crystals with homogenously distributing components and thin covering layer would help to determine the composition of fluid inclusions.     

Micro-PIXE and PIGE analysis of individual fluid inclusions

Using the high resolution microprobe which combines PIXE with PIGE measurements, components of trapped fluids can be measured without opening individual inclusions. It is a useful tool for nondestructive all elements' analysis. Micro-PIXE was used to detect the Z> 13 elements and the fluorine concentration was analyzed with micro-PIGE, using the ¹⁹F(p, γ)¹⁶O reaction at 872 keV resonance energy. Primary work of the elemental distributions including light elements in fluid inclusions is also given.     

Microspectrometric Investigation of Petrified Wood from South-Eastern Poland

 The investigation of the interesting collection of the petrified wood from Bondyrz, Roztocze, south-eastern Poland, has been continued. Two kinds of microprobes such as electron microprobe from the Catholic University of Lublin and synchrotron-based X-ray microprobe from LURE, Orsay, were applied to detect the elements associated with the main component – silica and their spatial distribution and interrelations. The distribution of carbon in the petrified material has been established, which is important since that element is the main remains from the history of the trees. The carbon distribution was characteristic – it concentrated on a place of primordial dark wood. The distribution patterns of the other elements were either similar to that of carbon (Cu, Pb) or they concentrated in separate inclusions (Fe, Al, K, Na, Ca). The replicating mode of the original wood pattern in silica and carbon-containing material was explained. Some indications about the composition of the primordial petrifying solution, the rate of the petrifaction process and the recent coloration of the sample could be concluded from the compositional patterns of silica. The boundary between totally and partially petrified zones could be well observed. Received October 2000. Revision March 6, 2001.     

Chemical analysis of thin films by means of SS-MS, GD-OES, and XPS demonstrated at Ir-Si thermoelectrica

Analytical methods with low detection limits were used for the investigation of Ir-Si thin films, the physical properties of which vary strongly with the chemical composition and the amount of impurities. It is demonstrated how to solve chemical characterization of different thermoelectric Ir-Si thin films by spark source mass spectrometry (SS-MS), glow discharge optical emission spectroscopy (GD-OES) and X-ray photoelectron spectroscopy (XPS). The combined use of the three different facilities allows the quantification of impurities of elements of the entire periodic system in the ppm range (down to 30 at.-ppm in dependence on the element) incorporated in thin film samples. Additional information about the in-depth distribution of elements or specifically bonded species can be achieved with a high depth resolution.     

Relative Cross Sections for L- and M-Shell Ionization by Electron Impact

 Results from measurements and calculations of relative L- and M-shell ionization cross sections by electron impact are presented. Measurements were performed for elements Te, Au and Bi on an electron microprobe with specimens consisting of extremely thin films of the studied element deposited on thin, self-supporting, carbon layers. The relative variation of the ionization cross section was obtained by counting the number of characteristic X-rays from the considered element and shell, for varying incident electron energies, from the ionization energy up to 40 keV. Measured data were corrected to account for the energy-dependent spread of the electron beam within the active film and for the ionization due to the electrons backscattered from the carbon layer, using Monte Carlo simulation. Cross sections were evaluated in the Born approximation using an optical-data model with numerically evaluated dipole photoelectric cross sections. Calculated ionization cross section were converted to vacancy production cross sections, which can be directly compared with our experimental data.     

Chemical analysis of thin films by means of SS-MS, GD-OES, and XPS demonstrated at Ir-Si thermoelectrica

Analytical methods with low detection limits were used for the investigation of Ir-Si thin films, the physical properties of which vary strongly with the chemical composition and the amount of impurities. It is demonstrated how to solve chemical characterization of different thermoelectric Ir-Si thin films by spark source mass spectrometry (SS-MS), glow discharge optical emission spectroscopy (GD-OES) and X-ray photoelectron spectroscopy (XPS). The combined use of the three different facilities allows the quantification of impurities of elements of the entire periodic system in the ppm range (down to 30 at.-ppm in dependence on the element) incorporated in thin film samples. Additional information about the in-depth distribution of elements or specifically bonded species can be achieved with a high depth resolution. Received: 6 April 1998 / Revised: 9 July 1998 / Accepted: 14 July 1998     

Proton microprobe analysis of interplanetary dust particles

Interplanetary dust particles (IDPs) are typically <10 μm in diameter and <10^?9 g in mass on collection. The Heidelberg proton microprobe (beam spot ?2 × 3 μm²) allows non-destructive detectio of trace elements in such samples. Two IDPs (Zodiac and Bounce) were examined. To evaluate the proton-induced x-ray spectra quantitatively, the x-ray production rates for thin samples were calculated with a computer routine; the elemental ratios of the samples normalized to silicon or iron were evaluated. The ratios found for the Zodiac sample agree within a factor of two with those of cosmic abundance. The other IDP showed depletion in Ca, K, Zn and S.     

Laser microprobe mass spectrometry (LMMS) of intracrystalline crown ether and cryptand complexes in layer silicates

Laser microprobe mass spectrometry (LMMS) allows the characterisation of organic inclusions in mineral materials. The complexes are detected as cationized or protonated molecules, arising from the intact desorption or from recombination within the laser generated microplasma. The results obtained sustain the interpretation from other techniques concerning the nature of the cation-ligand association and the proton exchange of the cryptand for acidic Cu²⁺-ions.     

The University of Surrey&;#39;s new proton microprobe and the feasibility of PIXE-tomography for trace element analysis of biological tissues

Summary The University of Surrey Ion Beam Centre has recently installed a tandem accelerator with a new proton microprobe and the potential for sub-micron beam-spot size. The facilities for Nuclear Microscopy (NM), combining scanning transmission ion microscopy/tomography (STIM-T) and proton induced X-ray emission tomography (PIXE-T) of biological tissues are being developed. This paper will review developments in ion beam tomography of biological samples and methods in accurately producing trace-elemental maps that are meaningful. Cell composition and integrity can be seriously compromized by the preparation of the sample and by beam-induced damage, causing loss of matrix elements as well as a change in cell size. Beam-induced damage, determination of 3-dimensional X-ray attenuation and secondary fluorescence contribute to the complex nature of the reconstruction and interpretation of PIXE-tomographic data. A PIXE, STIM and Rutherford backscatter analysis of leukocytes is presented in part to test the new microprobe but also to identify areas of improvement in facilities at the university and nuclear microscopy in general, in anticipation of producing maps for more direct biological and medical research.     

Understanding the History of Rocks by the Use of Microbeam Analysis Techniques

 In order to understand the physical and chemical processes that occur in complex systems such as geological materials, one needs to look at the minerals involved on as fine a scale as possible; studying the mutual relationships among the different phases in terms of texture, chemical composition, zonation, etc., in the original petrographic context. This paper reports how the study of a rock through microanalysis can be done. The potentialities of the various microanalytical techniques such as electron microprobe analysis (EMPA), cathodoluminescence (CL), particle-induced X-ray emission (PIXE), secondary ion mass spectrometry (SIMS) and accelerator mass spectrometry (ASM) are presented. Each of them has its own characteristics and limits. And only through a multiple-technique approach it is possible to investigate the various components of the rock system and from this, unravel its history.     

Determination of platinum-palladium micro inclusions in polymetallic ores by means of digital gamma-activation autoradiography

It has been demonstrated that digital gamma-activation autoradiography is an effective method for detection of platinum-palladium micro inclusions in the copper-nickel polymetallic ores of complex composition. Just two measurements of the samples (after irradiation and a week of cooling) are enough for contrast detection of such inclusions. To extend the method capabilities, a procedure of treatment of a set of the images obtained while cooling the samples has been developed. The procedure permits control of the inclusions composition and estimation of the main components ratio. It has been stated that gamma-activation autoradiography is highly suitable method for screening detection of inclusions in geological samples and it is quite reasonable to combine with scanning electron microscopy or X-ray microprobe techniques for further detailed investigations of the found inclusions peculiarities.     

质子交换膜燃料电池新结构

质子交换膜燃料电池（ＰＥＭＦＣ）能量效率和功率密度高,无电解质腐蚀,环境友好,可望广泛用于电动汽车的发电装置、便携式电源和地面发电站等．许多发达国家都投巨资对其进行研究开发［１］．传统的单对ＰＥＭＦＣ由膜～电极组件和其两侧的集流板构成,其中膜～电极组...     

Original position statistic distribution analysis (original position analysis)——A new analytical method in research and quality evaluation of materials

The property of the material is closely related to its chemical compositions and microstruc-tures, which are the important parameters in the judgement of the quality of the material. The conventional chemical composition content of the material is an average value of the chemical composition of the whole material tested or the content of a fix position. Although it is still neces-sary to further improve these conventional methods, there are mature and systematic methods for analyzing the conve…     

Characterization of Thin Polymer Films on the Nanometer Scale with Confocal Raman AFM

The combination of an atomic force microscope (AFM) with a Confocal Raman Microscope (CRM) has been used to study the composition of various thin films of polymer blends. The high spatial resolution of the AFM enables the morphological characterization of the polymer blends on the nanometer scale. Furthermore, when operating the AFM in Digital Pulsed Force Mode (DPFM), topographic information and local stiffness can be simultaneously recorded. This allows the material-sensitive characterization of heterogeneous materials. Thin films where PMMA (at room temperature a glassy polymer) is blended with two different styrene-butadiene rubbers are investigated. The presence of PMMA in both phase-separated thin films allows the comparison of the mechanical properties of the two different rubber phases using DPFM-AFM. When PMMA is blended with PET due to their similar mechanical properties (both are in the glassy state at room temperature) the assignment of the two phases to the corresponding polymers by AFM is rather difficult. Here, Raman spectroscopy provides additional information on the chemical composition of materials. In combination with a confocal microscope, the spatial distribution of the various phases can be determined with a resolution down to 200 nm. Therefore, the topographically different structures observed in AFM images can be associated to the chemical composition by using the Confocal Raman Microscope (CRM).     

The mutual diffusion coefficient for (meth)acrylate monomers as determined with a nuclear microprobe

The value of the mutual diffusion coefficient DV of two acrylic monomers is determined with nuclear microprobe measurements on a set of polymer films. These films have been prepared by allowing the monomers to diffuse into each other for a certain time and subsequently applying fast ultraviolet photo-polymerization, which freezes the concentration profile. The monomer diffusion profiles are studied with a scanning 2.1 MeV proton microprobe. Each monomer contains a marker element, e.g., Cl and Si, which are easily detected with proton induced x-ray emission. From the diffusion profiles, it is possible to determine the mutual diffusion coefficient. The mutual diffusion coefficient is dependent of concentration, which is concluded from the asymmetry in the Cl- and Si-profiles. A linear dependence of the mutual diffusion coefficient on the composition is used as a first order approximation. The best fits are obtained for a value of b=(0.38+/-0.15), which is the ratio of the diffusion coefficient of 1,3-bis(3-methacryloxypropyl)-1, 1,3,3-tetramethyldisiloxane in pure 2-chloroethyl acrylate and the diffusion coefficient of 2-chloroethyl acrylate in pure 1,3-bis(3-methacryloxypropyl)-1,1,3,3-tetramethyldisiloxane. Under the assumption of a linear dependence of the mutual diffusion coefficient DV on monomer composition, it follows that DV = (2.9+/-0.6)10(-10) m(2)/s at a 1:1 monomer ratio. With Flory-Huggins expressions for the monomer chemical potentials, one can derive approximate values for the individual monomer diffusion coefficients.     

Photon and proton activation analysis of iron and steel standards using the internal standard method coupled with the standard addition method

The internal standard method coupled with the standard addition method has been applied to photon activation analysis and proton activation analysis of minor elements and trace impurities in various types of iron and steel samples issued by the Iron and Steel Institute of Japan (ISIJ). Samples and standard addition samples were once dissolved to mix homogeneously, an internal standard and elements to be determined and solidified as a silica-gel to make a similar matrix composition and geometry. Cerium and yttrium were used as an internal standard in photon and proton activation, respectively. In photon activation, 20 MeV electron beam was used for bremsstrahlung irradiation to reduce matrix activity and nuclear interference reactions, and the results were compared with those of 30 MeV irradiation. In proton activation, iron was removed by the MIBK extraction method after dissolving samples to reduce the radioactivity of⁵⁶Co from iron via⁵⁶Fe(p,n)⁵⁶Co reaction. The results of proton and photon activation analysis were in good agreement with the standard values of ISIJ.     

Analysis of geological samples by the micro-PIXE facility at KFUPM

Summary The scanning microprobe facility of the 3 MV Tandetron accelerator at King Fahd University of Petroleum and Minerals (KFUPM) has been applied extensively in various fields, including geology. This paper reviews a number of geological investigations carried out on samples of gold-bearing rocks, phosphorite ores and volcanic sediments. Elemental composition and distribution maps across single mineral grains, fluid inclusions, grain boundaries and matrices were measured. The microscopic data obtained are discussed to understand fundamental geological processes and ore genesis, and the provenance of economically important trace minerals contained in these samples.     

Characterization of Precipitates in Ti-Stabilized Steels with Low-Energy Electron-Induced X-Ray Spectrometry and Scanning Electron Microscopy

 Various kinds of precipitates can influence the mechanical properties of Ti-stabilized steels. The qualitative composition of the Ti inclusions can be characterized microscopically, whereas for quantitative information to be obtained time-consuming selective dissolution must be used. The present study aims at chemical speciation of the isolated precipitates as a solid phase with the help of soft-X-ray spectrometry. Whether the method is capable of giving both qualitative and quantitative information on the composition of Ti-mixtures is discussed. The precipitates in Ti-stabilized steels are investigated after chemical dissolution of the steel matrix with a bromine/methanol mixture (1:10). By combination of soft-X-ray spectrometry with X-ray fluorescence (XRF) and scanning electron microscopy (SEM) both qualitative and quantitative characterization of the precipitates can be performed. They were found to consist mainly of TiC and TiN. Received July 1, 1998. Revision December 29, 1998.