THE TEMPERATURE-DEPENDENCE OF LUMINESCENCE IN SOME FELDSPARS (80-300-K)

The temperature dependence of luminescence recombination in samples of alkali feldspar and plagioclase samples has been measured directly us ing x-ray stimulation in the temperature range 80-300 K. Thermal quenc hing between 80 and 200 K has been observed in the UV-visible emission s from selected feldspar samples and the gain has been quantified. The rmal activation energies of the quenching mechanism have been evaluate d and are of the order 0.06 eV in potassium feldspars and 0.04 eV in p lagioclase samples. The similarities in quenching behaviour with both potassium feldspars and plagioclases in UV-visible emissions, together with the observations of quenching in other silicate materials and th e evidence from Raman and FTIR spectroscopy studies, indicate similar quenching mechanisms connected with lattice vibrations. By comparison with the Raman and FTIR studies, suggestions are made for the specific lattice motions responsible for the observed quenching.