Czochralski Growth and Scintillation Properties of Cerium-doped Li_6Gd(BO_3)_3 Crystals

Cerium-doped lithium gadolinium borate (Li6Gd(BO3)3:Ce) single crystals up to 25mm in diameter and 40mm in length were grown by the Czochralski method using inductively heated platinum crucibles. The as-grown Li6Gd(BO3)3:Ce crystals are of single-phase and they belong to the monoclinic system with space group of P21/c. Problems existing in crystal growth such as cleavage crack, stress crack and polycrystalline were discussed. The appearance of the perfect cleavage plane (020) was explained by considering the structure of Li6Gd(BO3)3. The results show that optical transmittance in the range of 380-800nm is near 90%. The absorption from 200nm to 380nm can be related to 4f-5d transitions of Ce3+ ions and 4f-4f transitions of Gd3+ ions. Both the emission under the optical excitation and the emission under X-ray excitation display the typical double-peaks characteristic of Ce3+ ions. Compared with the emission under the optical excitation, the emission under X-ray excitation shows a slight ' red shift ' . Decay time spectrum from Li6Gd(BO3)3:Ce can be well fitted with a decay time of 30.74ns. The energy resolution under the excitation ofα-ray from 241Am measured is 28.84%.