A magneto-optical study of the2T1g,4T2g,2Egfrom4A2gtransitions in K2NaGaF6:Cr3+

Abstract
The vibronic structure of the 2Eg to or from 4A2g transition of K2NaGaF6:Cr3+ is analysed with MCD and MCPE spectroscopy. The Jahn-Teller active Eg vibration is observed in both emission and absorption spectra. The analysis of the overlapping structure associated with the 2Eg from 4A2g and 4T2g from 4A2g transitions lead to the identification of the 2T1g from 4A2g transition. The 4T2g and 2T1g states lie about 550 and 1600 cm-1 above the 2Eg origin, respectively. These results are compared with crystal field and molecular orbital calculations.