Search

Single crystals of LuAG doped with Pr3+ ions (0.2 mol%) are grown by the micro-pulling-down (μ-PD) method with an RF heating system. The as-grown crystals are confirmed to be of garnet-type structure with the space group of Ia3d (230). The emission-excitation spectra and luminescence decay kinetics are measured in the temperature range of 5-310 K by using synchrotron radiation as an exciting light source. The intrinsic luminescence is observed at 250 nm at low temperatures. Four emission bands at 308, 325, 360, and 380 nm are ascribed to the 5d- > 4f transitions of Pr 3+ ions. From the decay kinetics measurements, it is pointed out that there exist two kinds of energy transfer mechanisms from the host LuAG lattice to the Pr 3+ ions. The mechanisms of energy transfer are discussed in connection with the formation of substitution-type defects. [ABSTRACT FROM AUTHOR]

CeF3 single crystals heavily doped with Sr2+ ions are grown by the micro-pulling-down (μ-PD) method. The deviation of the composition in as-grown crystals is found to be entirely negligible. Three dimensional emission-excitation spectra are measured in a wide temperature range of 5-300 K by using synchrotron radiation as an exciting light source. Two intense emission bands are observed at around 320 and 400 nm. The origin of these bands is discussed on the basis of the perturbation effects introduced by Sr doping. It is pointed out that the energy transfer takes place from Ce3+ sites to defect sites when the crystal is warmed from 5 to 300 K. [ABSTRACT FROM AUTHOR]

CeF3 single crystals heavily doped with Sr2+ ions are grown by the micro-pulling-down (μ-PD) method. The deviation of the composition in as-grown crystals is found to be entirely negligible. Three dimensional emission-excitation spectra are measured in a wide temperature range of 5-300 K by using synchrotron radiation as an exciting light source. Two intense emission bands are observed at around 320 and 400 nm. The origin of these bands is discussed on the basis of the perturbation effects introduced by Sr doping. It is pointed out that the energy transfer takes place from Ce3+ sites to defect sites when the crystal is warmed from 5 to 300 K. [ABSTRACT FROM AUTHOR]