Hannover 2010 – wissenschaftliches Programm
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K: Fachverband Kurzzeitphysik
K 4: Laseranwendungen und Lasermaterialbearbeitung I
K 4.6: Vortrag
Donnerstag, 11. März 2010, 12:00–12:15, F 442
Calibration free LIBS of oxide materials — •Bernhard Praher1,2, Johannes Heitz1,2, and Johannes Pedarnig1,2 — 1Christian Doppler Laboratory for Laser-Assisted Diagnostics, Johannes Kepler University Linz, Austria — 2Institute of Applied Physics, Johannes Kepler University Linz, Austria
Laser-induced breakdown spectroscopy (LIBS) enables to analyze the element composition of complex materials. For quantitative concentration analysis, calibration free LIBS (CF-LIBS) and multivariate calibration can be employed. We measured LIBS spectra of oxide materials and we modified the CF-LIBS method to increase the accuracy. The concentration of oxides was obtained by using stoichiometric relations. Sample materials were prepared from oxide powder (Fe2O3, MgO, CaO) by mixing and pressing. The concentration was 9.8 - 33.3 wt% Fe2O3, 7.6 - 33.3 wt% MgO and 33.3 - 81.2 wt% CaO for different samples. Nd:YAG laser ablation was performed in air. The laser-induced plasma emission was measured by an Echelle spectrometer equipped with a sensitivity calibrated ICCD camera. The numerical CF-LIBS algorithm included the spectra selection by linear correlation, the deconvolution of instrumental function, and the correction of self-absorption effects. The oxide concentration cCF calculated from CF-LIBS results and the nominal concentration cN were very close for all samples investigated. The relative error in concentration, | cCF - cN | / cN , was < 10 %, < 20 %, and < 5% for Fe2O3, MgO, and CaO, respectively. The results indicate that this method can be employed for the analysis of major elements in multi-component technical materials.