High resolution MCD and phosphorescence excitation spectroscopy of Mn²⁺ in KMgF₃ and KZnF₃

Abstract

A combination of high resolution MCD and phosphorescence excitation techniques has been used to determine, for the first time, the optical spectra of single Mn²⁺ ions in the cubic perovskite hosts KMgF₃ and KZnF₃. Particular attention has been paid to transition mechanisms, spin-orbit effects and vibronic structure, and the experimental results have been compared with theoretical crystal field calculations based on the complete d ⁵ configuration. All of the states arising from the ⁴ G, ⁴ P and ⁴ D terms have been observed and a dynamic Jahn-Teller effect has been observed in the ⁴ T _{1g ^a} state. Both magnetic dipole and electric dipole (vibrationally induced) absorption processes occur and the former is most important for transitions to the ⁴ T _1g ^a , ⁴ A _1g , ⁴ T _1g ^b states. Calculated and observed magnetic dipole intensities are in good agreement. A complete analysis of the zero phonon (magnetic dipole) lines and vibronic (magnetic and electric dipole) side-bands associated with transitions to ⁴ A _1g and ⁴ E _g ^a states has been made.