Papers by Keyword: PIXE

Abstract: The geochemical analysis of the middle Z precious metallic trace elements of the charnockite mineral composition was obtained by using proton induced X-ray emission at 3 MeV with a Si (Li) detector. Compared with other experimental nuclear analytical techniques like EPMA, XRF, and NAA, proton induced X-ray emission is used to detect with good accuracy and precision in the case of trace precious metals like Mo, Nb, Ru, Rh, and Ag, etc., in charnockite mineral composition due to the cross-sections with 3 MeV protons and good agreement. But peak resolution problems of K-X-rays of low Z and L-X-rays of the above elements which were presented in charnockite analysis must be solved and also change the detector parameters to obtain exact values in traces of the above elements in parts per million.

Abstract: 17NiCrMo7, 19MnCr5 and 27MnCr5 low-alloy case-hardening steels samples have been investigated by SANS (Small-Angle Neutron Scattering), to achieve data on bulk nanoscale structure characterisation and complementary analytical and crystallographic information. The reported results are related in particular to the size distribution of nanosized pores which can help to comprehend the structural basis for the physico-chemical properties and thus to improve quality and durability of the considered materials. A complementary PIXE investigation has been also carried out, with the aim of a non-destructive assessment of the elemental composition of the considered samples.

Abstract: This work aims to explore the sources of raw materials of archaic serpentine jade artifacts by comparing their trace element content. The major and trace elements of serpentine jade samples from different deposits in China are determined by external-beam proton-induced X-ray emission (PIXE). Trace element concentrations are also measured by inductively coupled plasma atomic emission spectroscopy for comparison. The relationship between the trace element content and the mechanism of serpentine formation is discussed. The results indicate that Type I jade has a small amount of Ni in it and almost no Cr and Co while significant amount of Cr, Co and Ni was found in Type II jade. Thus, this could be used to distinguish the two kinds of serpentine jade formed by different mechanisms.

Abstract: t was known that historical objects were highly heterogeneous. Due to the complex nature of materials and objects, extremely sensitive, spatially resolved, multi-elemental and versatile analytical instruments were needed. The techniques employed should be as a noninvasive as possible and able to give complementary information from macroscopic to nanometer scales. In this work, X-ray based spectroscopy including energy dispersive X-ray fluorescence spectroscopy (EDS), Proton-induced X-ray emission spectroscopy (PIXE), and micro-beam X-ray fluorescence spectroscopy (µ-XRF) were used to analyze chemical composition of the Lanna-style glass. Microstructure was also studied. It can be concluded that these techniques in combination are powerful for the investigation of heterogeneous glassy materials.

Abstract: The quantification of active ingredients (AI) in drugs is a crucial and important step in the drug quality control process. This is usually performed by using wet chemical techniques like LC-MS, UV spectrophotometry and other appropriate organic analytical methods. However, if the active ingredient contains specific heteroatoms (F, S, Cl…), elemental IBA like PIXE and PIGE techniques, using small tandem accelerator of 1-2 MV, can be explored for molecular quantification. IBA techniques permit the analysis of the sample under solid form, without any laborious sample preparations. In this work, we demonstrate the ability of the Thick Target PIXE technique for rapid and accurate quantification of both low and high concentrations of active ingredients in different commercial drugs. Fenofibrate, a chlorinated active ingredient, is present in high amounts in two different commercial drugs, its quantification was done using the relative approach to an external standard. On the other hand, Tiemonium methylsulfate which exists in relatively low amount in commercial drugs, its quantification was done using GUPIX simulation code (absolute quantification) The experimental aspects related to the quantification validity (use of external standards, absolute quantification, matrix effect,...) are presented and discussed.

Abstract: In this work the capability of the proton induced X-ray emission (PIXE) technique to monitor a rapid, non-destructive and accurate quantification of Al on or inside SiC is discussed. Optimization of PIXE acquisition parameters was performed using as reference, a thin Al film (2.5 nm) thermally evaporated onto silicon carbide substrate. In order to improve the sensitivity for Al detection and quantitative determination, a systematic study was undertaken using proton ion beam at different energies (from 0.2 to 3 MeV) with a different tilting angle (0°, 60°, and 80°). The limit of detection (LOD) was found to be lower than 0.02 nm. The optimum PIXE conditions (energy, angle) were applied for determining the Al doping concentration in thin (1 µm) 4H-SiC homoepitaxial layer. The Al concentration as determined by PIXE was found to be 3.9x1020 at/cm3 in good agreement with SIMS measurements, and the LOD was estimated to be 6x1018 at/cm3.

Abstract: The Thai amulets that created in an image of Lord Buddha meditation were made to explain the Dharma of Buddha and believed to bless every life in this world for good karma. Phra Somdej Wat Rakhang amulet is the top of the five most famous Thai amulets. There are many molds with various compositions. In this work, it was the first time that X-ray fluorescence spectrometry methods; scanning electron microscope cooperated with energy dispersive X-ray fluorescence spectrometer (SEM/EDS) and particle induced X-ray emission spectroscopy (PIXE) were carried out to analyze their compositions. Two samples were collected from different molds. Results revealed C, Ca and Si were main composition. The differences in their compositions have been used to identify and characterize for each molds.

Abstract: The major limitation of Bi-system superconductor applications is the intergrain weak links and weak flux pinning capability producing low critical current density of the Bibased phases. In order to enhance these characteristics and other superconducting properties, effective flux pinning centers are introduced into high temperature superconductors. In this work, different weight percentages of ZnO nano oxide were introduced at the final stage of the Bi_1.8Pb_0.4Sr₂Ca₂Cu₃O_10-y superconductor preparation process. Phase characterization was completed by X-ray diffraction (XRD). Exact constitution of the samples was determined using particle induced X-ray emission (PIXE). Granular and microstructure were investigated using scanning electron microscopy (SEM). Electrical resistivity as function of the temperature was carried to evaluate the relative performance of samples, and finally, E-J characteristic curves were obtained at 77K. Using 0.4 ZnO weight percentage, the electrical and granular properties were greatly enhanced, indicating more efficient pinning mechanisms. A critical current density of 949 A/cm2 was obtained which represents more than twice the value obtained for the pure sample (Jc= 445 A/cm2).

Abstract: Glasses have been used as decorative objects in Thailand for several hundred years. Decorative glasses can generally be seen as architectural components in old styled palaces and Buddhist objects. There were various colors ranging from transparent to amber, blue, green and red with different shades among glass of different colors. Fragments of archaeological glass samples were characterized for the first time using Raman microscopy with the aim of obtaining information that would lead to identification of the glass samples by means of laser scattering. The samples were also investigated using other techniques, such as particle induced X-ray emission spectroscopy and scanning electron microscope operated with energy dispersive X-ray fluorescence spectrometer. They were mostly lead-silica based glasses. The colors resulted from metal ions. The difference in chemical composition was confirmed by Raman signature spectra.

Abstract: In this work the capability of the proton induced X-ray emission (PIXE) technique to monitor a rapid, non-destructive and accurate quantification of Al on and in Si-based matrix is discussed. Optimization of PIXE acquisition parameters was performed using as reference a thin Al film (2.5 nm) thermally evaporated onto silicon substrate. In order to improve the sensitivity for Al detection and quantitative determination, a systematic study was undertaken using proton ion beam at different energies (from 0.3 to 3 MeV) with a different tilting angle (0°, 60°, and 80°). The limit of detection (LOD) was found to be lower than 0.2 nm. The optimum PIXE conditions (energy, angle) were applied for determining the Al doping concentration in thin (1 µm) 4H-SiC homoepitaxial layer. The Al concentration as determined by PIXE was found to be 3.9x1020 at/cm3 in good agreement with SIMS measurements, and the LOD was estimated to be 6x1018 at/cm3.