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

摘要

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, Al_2O_3, MgO, SiO_2, 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 ≥ 1 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.