OPTICAL-SPECTRA AND LUMINESCENCE DYNAMICS OF PR3-CRYSTALS( AND ND3+ IN SRLAALO4 SINGLE)

Single crystals of SrLaAlO4:Pr3+ and SrLaAlO4: Nd3+ have been grown by the Czochralski method and their optical properties have been studied for different activator concentrations. The absorption and emission s pectra of the activators are inhomogeneously broadened because the Sr2 + and La3+ ions are distributed randomly on the sites of C-4v symmetry , however, the symmetry selection rules are still obeyed. Strong self- quenching of the praseodymium luminescence occurs by cross relaxation which is supposed to be assisted by phonon emission in the case of the P-3(0) level. Self-quenching of Nd3+ luminescence disappears at low t emperature indicating that the condition of resonance in the cross-rel axation process is fulfilled only for higher components of the ground state.