Local lattice structure, crystal field and energy level patterns in CsCdBr3:Tm3+ crystals

In CsCdBr3, Tm3+ substitutes for Cd2+. It predominately forms symmetric dimer centers and single-ion centers, both of trigonal symmetry. The energy level schemes of both centers were determined by EPR and site-selective laser spectroscopy. To describe the spectra term dependent crystal-field parameters were deduced on the basis of a microscopic model taking into account the local lattice deformation induced by the impurity centers and the quasi-resonant virtual scattering of intrinsic lattice excitations by the Tm3+ ions. © 1998 Elsevier Science S.A