TY - JOUR
T1 - Enhancement of electron-induced X-ray intensity for single particles under grazing-exit conditions
AU - Tsuji, Kouichi
AU - Spolnik, Zoya
AU - Wagatsuma, Kazuaki
AU - Zhang, Jing
AU - Van Grieken, René E.
N1 - Funding Information:
K. Tsuji was financially supported by Japan Society for the Promotion of Science (JSPS). Z. Spolnik and J. Zhang were supported by the project ENV4-CT 95-0104 and -0088, respectively. The authors thank Dr P.K. de Bokx (Philips Research Laboratories) for the supply of Si wafers, Dr J. Osán (UIA) and Mr R. Nullens (UIA) for useful suggestions.
PY - 1999/8/9
Y1 - 1999/8/9
N2 - Grazing-exit electron probe microanalysis (GE-EPMA) was performed for single Al2O3 and atmospheric particles, deposited on a flat Si substrate coated by gold, by using an aperture (1 mm in diameter) in front of an energy-dispersive X-ray detector. Silicon Kα X-rays from the Si substrate were strongly observed at an exit angle of approx. 45°C. However, they disappeared at grazing-exit angles about 0° and only the X-rays from particles were detected. Furthermore, Al Kα and O Kα intensities from single Al2O3 particle were enhanced approximately three- and sixfold at the grazing-exit angles (approx. 1°), respectively, in comparison with those at large angle (approx. 7°). The background intensities at the energy of Al Kα and O Kα almost monotonously decreased with decreasing exit angle. As a result, the intensity ratios of Al Kα and O Kα X-rays to the background intensities were enhanced five- and sixfold, respectively. This enhancement is considered to be caused by the interference effect of both directly detected X-rays and reflected X-rays on the flat substrate. The similar results are also obtained for Al Kα, Si Kα, K Kα and Ca Kα emitted from single atmospheric particle. The significance of the matrix effect in the particle is also pointed out.
AB - Grazing-exit electron probe microanalysis (GE-EPMA) was performed for single Al2O3 and atmospheric particles, deposited on a flat Si substrate coated by gold, by using an aperture (1 mm in diameter) in front of an energy-dispersive X-ray detector. Silicon Kα X-rays from the Si substrate were strongly observed at an exit angle of approx. 45°C. However, they disappeared at grazing-exit angles about 0° and only the X-rays from particles were detected. Furthermore, Al Kα and O Kα intensities from single Al2O3 particle were enhanced approximately three- and sixfold at the grazing-exit angles (approx. 1°), respectively, in comparison with those at large angle (approx. 7°). The background intensities at the energy of Al Kα and O Kα almost monotonously decreased with decreasing exit angle. As a result, the intensity ratios of Al Kα and O Kα X-rays to the background intensities were enhanced five- and sixfold, respectively. This enhancement is considered to be caused by the interference effect of both directly detected X-rays and reflected X-rays on the flat substrate. The similar results are also obtained for Al Kα, Si Kα, K Kα and Ca Kα emitted from single atmospheric particle. The significance of the matrix effect in the particle is also pointed out.
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U2 - 10.1016/S0584-8547(99)00073-7
DO - 10.1016/S0584-8547(99)00073-7
M3 - Article
AN - SCOPUS:0032592699
VL - 54
SP - 1243
EP - 1251
JO - Spectrochimica Acta - Part B Atomic Spectroscopy
JF - Spectrochimica Acta - Part B Atomic Spectroscopy
SN - 0584-8547
IS - 8
ER -