On the mechanism of Eu→Mn energy transfer in monocrystalline NaCl

Abstract

Integrated intensity and lifetime measurements of the Eu 2+ and Mn 2+ emissions were carried out in the temperature range 10-300 K in order to obtain information on the mechanism of the Eu to Mn energy transfer in monocrystalline NaCl. Calculations based on the Forster-Dexter model of energy transfer indicate that the fast rise time of the Mn fluorescence after pulse excitation of Eu 2+ can only be explained if a short-range interaction such as an electric dipole-quadrupole of exchange-type interaction is active. These calculations also substantiate the model proposed by Rubio and co-workers (1987) in the sense that energy transfer from Eu 2+ to Mn 2+ in the lattice of NaCl takes place in the Eu-Mn pairs which are preferentially formed in this material.