Fast (Ce,Gd)<sub>3</sub>Ga<sub>2</sub>Al<sub>3</sub>O<sub>12</sub> Scintillators Grown by the Optical Floating Zone Method
Tong Wu, Ling Wang, Yun Shi, Tianzhao Xu, Hui Wang, Jinghong Fang, Jinqi Ni, Huan He, Chaoyue Wang, Bo Wan, Dongzhou Ding, Zhenzhen Zhou, Qian Liu, Qin Li, Jianding Yu, Xintang Huang, О. О. Шичалин, Е. К. Папынов
Abstract
A series of (CexGd1–x)3Ga2Al3O12 (x = 0–0.8%) (Ce/GGAG) crystals were grown by the optical floating zone (OFZ) method. Ce/GGAG single crystals with good crystallinity were successfully obtained by introducing oxygen atmosphere (100%) and auxiliary pressure (0.3 MPa) to suppress Ga2O3 volatilization in a container-free environment. The photoluminescence (PL) and scintillation properties of those Ce/GGAG crystals with different Ce3+ doping concentrations were investigated. In the 0.2–0.8 at. % Ce concentration range, the integral PL intensities were found to vary according to the approximate Gaussian distribution with Ce concentration, and the 0.6 at. % Ce/GGAG crystal has the highest integral PL intensity. Gd3+ emission was observed under X-ray excitation, which was rarely reported before. The maximum light yield reaches to 38,848 pho/MeV in the 0.6 at. % Ce/GGAG crystal. More importantly, fast decay and high ratio of the fast component (71 ns 66%) were successfully obtained in Ce/GGAG crystals with a Ga/Al = 2/3 ratio, which might be attributed to the suppression of composition deviation by introducing O2 (100%) atmosphere during crystal growth. It indicates that the optical floating zone method is effective in the composition engineering study of Ce/GGAG crystals to optimize the scintillation performance.