ENDOR and transferred spin densities of the 4f¹³ions in fluorides

Abstract

The ENDOR of Tm2+ cubic paramagnetic centres in KMgF3 is investigated. The data on the measurements of the transferred hyperfine interaction (THFI) parameters are compared with the THFI data for Tm2+ in CaF2 and Yb3+ in KMgF3, CaF2. For the interpretation of the total experimental data a new model in which, along with the covalency, the processes of charge transfer to the empty 5d shell and the processes of excitation of the outer 5p6 shell with its successive occupation by the electron of the nearest fluorine shell play an essential role is proposed.