The annealing effects of Lu0.8Sc0.2BO3:Pr3+ scintillation crystal within different atmospheres

The air-annealing effects on Lu0.8Sc0.2BO3:Pr3+ crystals grown by Czochralski method (Cz-method) were studied at different temperatures. Its scintillation efficiency reached optimum of about 500% of BGO after annealing at 1000 °C due to the removal of the oxygen vacancies. However, after annealing at a higher temperature, it was found that its scintillation efficiency was evidently reduced, because of oxidization of praseodymium ions. Through experiments, results show for Pr3+-doped Lu0.8Sc0.2BO3 scintillator, air-annealing plays either positive or negative role, depending on annealing temperature: low temperature annealing is favorable for the removal of oxygen vacancies, but annealing at high temperature causes oxidation of Pr from trivalent to tetravalent state, which are demonstrated by H2 annealing experiment.

Figure optionsDownload as PowerPoint slideHighlights
► Air-annealing plays either positive or negative roles in the change of luminescent efficiency.
► The scintillation efficiency depends on the annealing conditions.
► The level of oxygen vacancies is about 1.4 eV below the 5d level of Pr3+.