The influence of temperature quenching on the decay of fluorescence

Temperature quenching causes a marked increase of the rate of decay of fluorescence. It is shown that both the efficiency of fluorescence and the decay are determined by the probabilities of the fluorescence transition and of a radiationless transition. By combining data from measurements of the efficiency and the decay, it is possible to obtain the two transition probabilities separately, and both as a function of the temperature. The results with (NH 4 ) 3 UO 2 F 5 and Mg 2 TiO 4 . Mn 4+ have been used to verify whether the radiationless process follows the theory of Mott and Seitz, or of Moglich and Rompe; they are found to favour the former.