Magnetic circular dichroism of transition metal ions in solids-II K2NaGaF6

Abstract

The absorption and MCD spectra of the 4A2g → 4T2g, 4A2g, 4A2g → 4T1ga and 4A2g → 4T1gb spin-allowed transitions of Cr3+ in K2NaGaF6 are reported. It is shown that transitions to the 4T1g. states are induced by T1u vibratio the other spin-allowed transition, 4A2g → 4T2g, there are three competing intensity mechanisms: electric dipole induced by T1u vibrations, electric dipole induced by T2u vibrations and magnetic dipole, and an estimate is made of the relative importance of these. The magnetic dipole 4A2g → 2Eg zero-phonon line is observed to be accompanied by a vibrational sideband for which the coupling is predominantly with T2u vibrations. Other weak transitions are observed in MCD spectra and their origin briefly discussed. Show more