Radiation-Induced Accumulation of Structural Defects in MgF_2 Crystals Doped with Rare-Earth Impurities

摘要

Radiation-optical and luminescent properties of the MgF_2 crystals doped with RE impurities (RE = Pr, Sm, Tb, Ho, Tm, and Yb) are studied. The RE impurities are shown to affect the radiation-induced generation of the F-centers in a two-fold way. On one hand, due to highly efficient conversion of energy of auto-localized excitons into light, they reduce the yield of the F-centers, on the other, because of the difference between ionic radii of impurity ions and Mg~(2+), the defect-formation energy decreases, which increases the F-center yield. In addition, introduction of the RE-impurities reduces the migration energy of the defects, which stimulates coagulation of the F-centers and formation of the M-centers.