OPTICAL-PROPERTIES OF TL2-CENTERS IN ALKALI-HALIDES - I - INVESTIGATION WITH OPTICAL-DETECTION OF PARAMAGNETIC-RESONANCE( HOLE)

The spectra of the magnetic circular dichroism of the absorption (MCDA ) and of optically detected electron paramagnetic resonance (ODEPR) of Tl2+ hole centres have been investigated in a number of alkali halide s. Several new absorption bands were found using excitation spectra of the Tl2+ ODEPR lines. The number of the MCDA transitions of Tl2+ in t he bromides and especially in the iodides is larger than predicted by the molecular orbital picture discussed so far in the literature. An e xplanation will be given in part II by Cabria et al on the basis of MS -X alpha calculations including the spin-orbit effects of the ligands.