Heteroelemental diatomic secondary ions as a probe for molecular states

Summary The complete chemical characterization of environmental particles requires a depth resolved analysis of the chemical state of the elements. Using dynamic SIMS, a depth-resolved determination of the chemical state of chromium was derived from measurements of ten different chromium salts and oxides. The evaluation is based on the signals of Cr ₂ ⁺ , CrO⁺ and Cr₂O⁺ which are the most intense molecular ions. The valence state of chromium can be determined for concentrations far less than 1 atom %. The transferability of this kind of analysis is shown for manganese compounds. Additionally binary mixed metal clusters are shown to indicate binding partners of compounds in mixtures.