COMBINATION OF THREE LASER SPECTROSCOPIC METHODS FOR ANALYSIS OF APATITES

摘要

In our research selected apatite minerals from several locations in Finland have been investigatedusing Raman spectroscopy, laser-induced breakdown spectroscopy (LIBS) and photoluminescencespectroscopy, also known as laser-induced fluorescence (LIF). Combination of the three laserspectroscopy techniques can offer new insights to the analysis of apatite. Raman spectroscopydetects strong signal originating from the phosphate vibrations, which can be used to quicklyseparate location of apatites from other minerals. LIBS ablates a small amount of the samplematerial and the directly obtained plasma emission spectrum shows the atomic lines, revealing theelemental composition of the mineral. LIBS is capable of detecting also light elements likephosphorus (P), carbon ©, magnesium (Mg), etc. Apatite minerals are known to contain varietiesof rare-earth elements (REE) and photoluminescence can be used to map their locations on thesample surface. The time-resolved photoluminescence of apatite is well-investigated (e.g., ).With this method, the luminescence activator elements can be easily recognised even in ppm leveland for example short-lived Ce~（3+） luminescence can be separated from long-lived species. Addedtogether, these complementary laser spectroscopic techniques can offer a holistic view for theimproved characterisation of the apatite group minerals (Fig. 1.).