Kinetics and Temperature Dependences of Polarized Emission of Anisotropic Tin Centres in Alkali Halides

Temperature and time dependences of the polarized A emission of tetragonal Sn2+v centres in alkali halides have been investigated under excitation in the A absorption band. The change of polarization during the relaxation time, low‐temperature depolarization due to the tunnel transitions between the minima of the lowest excited states, evidence of the metastable state in emission processes, and high‐temperature depolarization due to the jumps of cation vacancy (v ) around Sn2+, have been observed. A model is proposed for the excited states of Sn2+, in which the electron‐lattice interaction is considered to be the main interaction, while the Spin–orbit interaction is taken into account as an additive correction. The formulae have been obtained for temperature and time dependences of polarization and decay time. Some parameters of Sn2+v centres in KCl:Sn have been found from comparison of the formulae with experimental data.