Atomic Absorption Spectroscopy: An In Situ Diagnostic for Sputter Deposition of Y-Ba-Cu-Oxide

1990 ◽  
Vol 201 ◽  
Author(s):  
G. Metzger ◽  
A. J. Blair ◽  
C. B. Fleddermann

AbstractAtomic absorption spectroscopy (AAS) has been used as an in situ diagnostic tool to study sputtering of high-temperature superconductors. Hollow-cathode lamps were used as line sources to measure relative atomic species concentrations during sputtering of Y-Ba-Cu-oxide targets using a Kaufman ion gun. The AAS measurements showed that the fluxes of ground state Ba and Cu ejected from a composite target during argon- and oxygen-ion bombardment varied greatly with sputtering parameters. Measurements were made of the effects of changes in ion-beam energy, ion flux to the target, and target temperature. In addition, the variation in atomic densities of Ba and Cu with distance from the target were measured. For comparison, AAS measurements during argon- and oxygen-ion sputtering of a pure copper target were also performed. The AAS results were verified by measuring stoichiometry variations of thin films deposited under identical conditions.

Sensors ◽  
2020 ◽  
Vol 20 (2) ◽  
pp. 533 ◽  
Author(s):  
Jan Viljanen ◽  
Kim Kalmankoski ◽  
Victor Contreras ◽  
Jaakko K. Sarin ◽  
Tapio Sorvajärvi ◽  
...  

Industrial chemical processes are struggling with adverse effects, such as corrosion and deposition, caused by gaseous alkali and heavy metal species. Mitigation of these problems requires novel monitoring concepts that provide information on gas-phase chemistry. However, selective optical online monitoring of the most problematic diatomic and triatomic species is challenging due to overlapping spectral features. In this work, a selective, all-optical, in situ gas-phase monitoring technique for triatomic molecules containing metallic atoms was developed and demonstrated with detection of PbCl2. Sequential collinear photofragmentation and atomic absorption spectroscopy (CPFAAS) enables determination of the triatomic PbCl2 concentration through detection of released Pb atoms after two consecutive photofragmentation processes. Absorption cross-sections of PbCl2, PbCl, and Pb were determined experimentally in a laboratory-scale reactor to enable calibration-free quantitative determination of the precursor molecule concentration in an arbitrary environment. Limit of detection for PbCl2 in the laboratory reactor was determined to be 0.25 ppm. Furthermore, the method was introduced for in situ monitoring of PbCl2 concentration in a 120 MWth power plant using demolition wood as its main fuel. In addition to industrial applications, the method can provide information on chemical reaction kinetics of the intermediate species that can be utilized in reaction simulations.


2018 ◽  
Vol 28 (4) ◽  
pp. 1259-1264
Author(s):  
Kiril Lisichkov ◽  
Katerina Atkovska ◽  
Neven Trajchevski ◽  
Orce Popovski ◽  
Nadica Todorovska

The presence of some chemical compounds at higher levels than maximum permissible concentrations (MPC) in the drinking water, suggests of water resources pollution. In this paper the following elements were analyzed: total arsenic, cadmium, lead, cooper and zinc. Twelve samples of water from the water supply system from the city of Skopje were examined during one year from three different springs. Also, ten samples of bottled water from three producers from the Macedonian market were tested.The determined average mass concentrations of total As, Cd(II), Pb(II), Cu(II) and Zn(II) in the analyzed water samples from the water supply system are 1.35 μg/l, 0.06 μg/l, 0.6 μg/l, 0.9 μg/l and 1,12 μg/l, respectively, and for the tested bottled water, the mean values ranges from 0.56 - 0.83 μg total As / l, 0.053 - 0.056 μg Cd(II)/l, 0.51 - 0.54 μg Pb(II)/l , 0.6 - 0.87 μg Cu(II)/l and 0.68 - 0.8 μg Zn(II)/l water.The following instrumental analytical methods and techniques were used for the analysis of the tested samples of drinking water: flame atomic absorption spectroscopy (AAS), atomic absorption spectroscopy with hydride cеll, electrothermal atomic absorption spectroscopy.The obtained results are shown in tables and graphic form. According to the obtained results a comparative analysis was carried out indicate that it is a water of good quality that can be used in different branches of the process industry.The obtained results in this paper do not exceed the values of the MPC of the Republic of Macedonia prescribed by the legal regulations for the drinking water, which confirm the health safety of the drinking water from the water supply system in the city of Skopje and the packed waters from the Macedonian market in relation to the tested elements.


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