Crystal growth and characterization of Tm doped mixed rare-earth aluminum perovskite

摘要

In this work, we present results of structural characterization and optical properties including radio luminescence of (Lu_xGd_yY_(0.99-x-y)Tm_(0.01))AP single crystal scintillators for (x, y) = (0.30, 0.19), (0, 0.19) and (0, 0) grown by the micro-pulling-down (|x-PD) method. The grown crystals were single phase materials with perovskite structure [Pbnm) as confirmed by XRD and had a good crystallinity. The distribution of the crystal constituents in growth direction was evaluated, and significant segregation of Lu and Gd was detected in (Lu_xGd_yY_(0.99-x-y)Tm_(0.01))AP sample. The crystals demonstrated 70% transmittance in visible wavelength range and some absorption bands due to Tm~(3+), Gd~(3+) and color centers were exhibited in 190-900 nm. The radioluminescence measurement under X-ray irradiation demonstrated several emission peaks ascribed to 4f-4f transitions of Tm~(3+) and Gd~(3+). The ratio of emission intensity in longer wavelength range was increased when Y was replaced by Lu or Gd.