Electron paramagnetic resonance (EPR) and optical absorption spectra were measured during thermal annealing for stoichiometric MgAl2O4 spinel that was previously irradiated in FFTF-MOTA at ~405C to ~50 dpa. Both F and F+ centres are to persist up to very high temperatures (over 700C), suggesting the operation of an annealing mechanism based on evaporation from extended defects Using x-ray irradiation following the different annealing steps it was shown that the optical absorption band is related to a sharp EPR band at g=2.0005 and that the defect causing these effects is the F+ centre.
Revised: March 29, 2005 |
Published: January 1, 2005
Citation
Ibarra A., D. Bravo, F.J. Lopez, and F.A. Garner. 2005.High dose neutron irradiation of MgAl2O4 spinel: effects of post-irradiation thermal annealing on EPR and optical absorption.Journal of Nuclear Materials 336, no. 2-3:156-162.PNNL-SA-40779.