Effect of annealing and gamma irradiation on undoped and Eu3+-doped Y2SiO5 single crystals

The absorption spectra of the undoped Y2SiO5 and Eu3+-doped Y2SiO5 crystals grown by the Czochralski technique were compared before and after annealing and, similarly, the unannealed and annealed crystals after γ-ray irradiation. The absorption bands of Eu2+ ions with peaks at 300 and 390 nm were observed in the as-grown Y2SiO5:Eu3+ crystal. These peaks were more intense in H2-annealed and irradiated Y2SiO5:Eu3+ crystals. The additional absorption peaks at 260 and 320-330 nm which were attributed to F color centers and O− hole centers were observed in irradiated undoped Y2SiO5 and Y2SiO5:Eu3+ crystals, respectively.