Element analysis of complex materials by calibration-free laser-induced breakdown spectroscopy

Laser-induced breakdown spectroscopy (LIBS) is a promising method for fast and quantitative element analysis of complex materials. We report on LIBS measurements of multi-component oxide materials and the compositional analysis of materials by a calibration-free (CF) method. This CF-LIBS method relies on modeling of the optical emission of laser-induced plasma assuming local thermodynamic equilibrium. Various materials are investigated and the calculated concentration values (C (CF)) of oxides CaO, Al2O3, MgO, SiO2, FeO, and MnO are in agreement with nominal concentration values (C (N)) from reference analysis. The relative error in oxide concentration e (r)=|C (CF)-C (N)|/C (N) decreases with increasing concentration. The quantification is limited to major oxides (C (N)a parts per thousand yen1 wt%). Slag samples from industrial steel production are analyzed on site by means of a mobile measurement system. LIBS measurements are performed at different sample temperatures. The results obtained show that CF-LIBS is applicable to fast compositional analysis of complex materials in harsh environments.