Abstract: In this paper, crack-free YAlO₃∶Ce (YAP∶Ce) crystals with size of ø35 mm×70 mm were grown by medium frequency induction Czochralski method. XRD results show that the main phase of YAP∶Ce crystal is YAP phase and the second phase is YAG phase. Photoluminescence emission spectra show that the emission wavelengths of the crystal are located at 344 nm and 376 nm, and the excitation wavelengths are located at 273 nm, 290 nm and 305 nm respectively. X-ray emission spectrum shows that the crystal emission wavelength is around 377 nm. The decay time curve of YAP∶Ce crystal decreases exponentially under the excitation of γ high-energy rays. After exponential decay fitting, the decay time of YAP∶Ce crystal is 46 ns. After Gaussian fitting, the energy resolution and absolute light yield of YAP∶Ce crystal are 8.51% and 8 530 ph/MeV respectively. The reasons of cracking and phase transition during crystal growth were analyzed. The crack-free crystals can be obtained by optimizing temperature fields and processes. How to obtain larger size crystals without cracking, phase transition and achieve their mass production is an important technical problem to be solved in the large-scale application of the crystal.

Key words: YAlO₃∶Ce, scintillation crystal, Czochralski method, crystal growth, scintillation property, cracking, phase transition