Impurity luminescence centers in fluorapatite from quartz-bearing paragenesis according to photo-, cathode- and synchrotron-induced luminescence

Apatite is typically characterized by a wide variety of spectrum and kinetic characteristics of luminescence; luminescent images of grains are often zonal. A variety of conditions for the formation of the mineral in various types of associations and in many types of host rocks contributes to the occurrence of impurities of various luminogen ions in its structure. The variety of luminescence is associated with impurities of d-metals, REE, different types of anions, as well as with the effects of co-activation in various combinations. The paper presents the results of a comparative study of photo-, cathode- and synchrotron luminescence of apatite (by the example of samples from crystal-bearing deposits of the Neroi region, Subpolar Urals). Using a Jeol JSM6390LV SEM equipped with a Horiba H-CLUE iHR500 attachment, cathodoluminescence spectra of apatite were obtained in the 200–800 nm range. The spectra and kinetic characteristics of apatite luminescence upon excitation by synchrotron radiation at 10 and 300 K have been analyzed for the first time; the physical nature of the excitation bands of the three main luminescence centers Ce3+, Eu2+ and Mn2+ has been examined; it is shown that the luminescence excitation with the energy transfer can be carried out in processes initially initiated by interband transitions or photoionization. The data obtained are important for expanding the possibilities of mineral cathodoluminescence with spatial and spectral resolution and its use in applied problems.