“…An enhancement of the activator luminescence is recognized for systems with an energy transfer between the host lattice and the activator (e.g. Y,A1,0,,: Ce3+ [l, 21, Cd,-,Ca,Al,Ge,O,,: Mn2+ [3], Cd,-,Ca,Al,Ge,O,, :Tb3+ [4]). In this paper we study the energy transfer between defect centres of the host and activator ions for the system Cd,-,Ca,Ga,Ge,O,~ activated with Nd3+ and Tb3+.…”