Real-time in situ flux monitoring in molecular beam epitaxy by wavelength-modulated atomic absorption spectroscopy

2007 ◽  
Vol 25 (4) ◽  
pp. 1398
Author(s):  
D. Vignaud
Keyword(s):  
Molecular Beam Epitaxy ◽  
Atomic Absorption ◽  
Real Time ◽  
Absorption Spectroscopy ◽  
Atomic Absorption Spectroscopy ◽  
Molecular Beam ◽  
Flux Monitoring

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
Keyword(s):  
Atomic Absorption ◽  
Absorption Spectroscopy ◽  
Atomic Absorption Spectroscopy ◽  
Ion Beam ◽  
High Temperature Superconductors ◽  
Pure Copper ◽  
Composite Target ◽  
Copper Target ◽  
Oxygen Ion

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.

scholarly journals Sequential Collinear Photofragmentation and Atomic Absorption Spectroscopy for Online Laser Monitoring of Triatomic Metal Species

Sensors ◽  
2020 ◽  
Vol 20 (2) ◽  
pp. 533 ◽  
Author(s):  
Jan Viljanen ◽  
Kim Kalmankoski ◽  
Victor Contreras ◽  
Jaakko K. Sarin ◽  
Tapio Sorvajärvi ◽  
...  
Keyword(s):  
Atomic Absorption ◽  
Gas Phase ◽  
Absorption Spectroscopy ◽  
Atomic Absorption Spectroscopy ◽  
Limit Of Detection ◽  
In Situ Monitoring ◽  
Metal Species ◽  
Chemical Reaction Kinetics

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.

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