Optical absorption and Raman studies of neutron-irradiated Gd3Ga5O12 single crystals Articles uri icon

authors

  • MIRONOVA ULMANE, N.
  • SILDOS, I.
  • VASIL'CHENKO, E.
  • CHIKVAIDZE, G.
  • SKVORTSOVA, V.
  • KAREIVA, A.
  • MUÑOZ SANTIUSTE, JUAN ENRIQUE
  • PAREJA PAREJA, RAMIRO
  • ELSTS, E.
  • POPOV, A. I.

publication date

  • November 2018

start page

  • 306

end page

  • 312

volume

  • 435

International Standard Serial Number (ISSN)

  • 0168-583X

Electronic International Standard Serial Number (EISSN)

  • 1872-9584

abstract

  • In this work we have performed a comparative analysis of optical absorption and micro-Raman spectra for series of Gd3Ga5O12 (GGG) single crystals irradiated by fast neutrons with fluences from 10(16) n/cm(2) to 10(18) n/cm(2). It was found that the optical absorption spectra of non-irradiated Czochralski grown GGG consist of the relatively narrow lines in the UV spectral range related to the 4f-4f transitions in Gd3+. Transitions from the S-6(7/2) ground state to the P-6, (6)J and D-6 states in a Gd3+ cation are clearly detected. For a GGG crystal containing Ca impurity ions, additional absorption band at 350 rim is observed, and it is tentatively ascribed to oxygen vacancies associated with Ca impurities. Several neutron-induced optical absorption bands, including ones related to F+ centres, were observed in fast neutron-irradiated Gd3Ga5O12 single crystals. Furthermore, clear evolution of the Raman spectra with neutron dose is also found. In particular, fine structure observed between 1350 and 1550 cm(-1) is completely disappeared at high fluences, while several significant changes and the emergence of new transitions have been ascertained in spectral range of 100-850 cm(-1).

keywords

  • radiation defects; optical absorption; raman; thermal annealing; neutron irradiation; gd3ga5o12; displacement defect formation; up-conversion luminescence; transient color-centers; doped gd3ga5o12; mgo; photoconversion; diffusion; kinetics; oxides; model