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

Full text: 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. Materials containing up to eight different oxides are investigated and for all samples the calculated concentration values (CCF) are in good agreement with nominal concentration values (CN) from reference analysis. The relative error in oxide concentration, er = | CCF - CN | / CN , decreases with increasing concentration. The quantitation is limited to major oxides (CN ≥ 1 wt %). Slag materials from industrial steel production are analyzed on-site by means of a mobile measurement system. LIBS measurements are performed at different sample temperature. The results obtained show that CF-LIBS is applicable to fast compositional analysis of complex materials in harsh environment. (author)