Depth profile studies of Zn-coated sheets by LA-ICP-MS, LA-ICP-OES and LIBS
Authors | |
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Year of publication | 2004 |
Type | Article in Proceedings |
Conference | 11th Solid Sampling Colloquium with Atomic Spectrometry |
MU Faculty or unit | |
Citation | |
Field | Analytic chemistry |
Keywords | depth profile; LA-ICP-MS; LA-ICP-OES; LIBS |
Description | For coatings and layers of thickness between tens of nm and tens of mm, the glow discharge optical emission spectrometry (GD-OES), is currently employed for quantitative depth profiling. Laser ablation (LA) combined with ICP-MS or as an emission source for laser-induced breakdown spectroscopy (LIBS) might be useful tool for the depth profile analysis of coatings with thickness in the range from units to tens of micrometers. However, depth resolution might be deteriorated due to a too large ablation depth per laser shot, a non-uniform radial energy distribution (Gaussian) in the laser beam, and rugosity at the bottom of the crater. Zinc-coated iron sheets (hot dipped and galvanically coated) of thickness between 6 an 30 um were studied by means of LA-ICP-MS system [1]consisting of a homogenized 193 nm ArF* laser ablation system (GeoLas, Microlas, Göttingen, Germany) coupled to an ICP-QMS Agilent 7500 (Agilent Technologies, USA). The sample in the ablation cell can be observed during ablation through the petrographic microscope with Schwartzschild objective (Axioplan, Zeiss) on a TV camera. Crater diameter can be varied using apertures between 4 and 120 um by changing the aperture diameter. The influence of the crater width (10-80 um), laser repetition rate (1-10 Hz), and power per pulse on depth resolution in the coating/substrate interface were studied. Comparative experiments were conducted with the laboratory-built LIBS system consisting of the Nd:YAG laser Quantel Brilliant operated at its fundamental wavelength 1064 nm with a repetition rate 10 Hz. Emission of breakdown plasma from ablation chamber was collected by a fiber optic system and delivered onto an entrance slit of the Jobin Yvon TRIAX 320 monochromator. Sample aerosol from the ablation chamber was transported by carrier gas directly into the plasma torch of ICP-OES Jobin Yvon 170 Ultrace. |
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