LUMINESCENCE FROM PURE MNF2 AND FROM MNF2 DOPED WITH EU3+ AND ER3+

In this paper we report fluorescence measurements made over a range of temperatures on nominally pure and on Er- and Eu-doped MnF2. By studying the weak intrinsic fluorescence in nominally pure samples we can draw some conclusions about exciton decay and energy-transfer processes. The decay rate of the E1 excitons is dominated by transfer to traps and depends strongly on temperature, exhibiting an activation behavior proceeding through a higher-E2 state. In the rare-earth-doped crystals the optical excitation energy is shared between the Mn traps and the rare-earth ions. As the temperature is raised the excitation is redistributed between the rare-earth ions and the effective Mn traps leading to a temperature-dependent variation in the fluorescence spectra from these crystals. © 1979 The American Physical Society.