Ce∶LuAlO_3晶体的热稳定性研究  

THERMAL STABILITY OF Ce∶LuAlO_3 CRYSTALS

作　　者：丁栋舟[1] 任国浩[1] 陆晟[1] 李焕英[1] 秦来顺[1] 

机构地区：[1]中国科学院上海硅酸盐研究所,上海201800

出　　处：《硅酸盐学报》2006年第3期261-265,共5页Journal of The Chinese Ceramic Society

基　　金：国家自然科学基金(50272072)资助项目。

摘　　要：铈掺杂铝酸镥(Ce∶LuAlO_3)晶体是一种具有钙钛矿结构的新型无机闪烁体。用提拉法试图从n(Lu2O3)∶n(Al2O3)=1∶1的熔体中生长Ce∶LuAl O3晶体。实验表明在缓慢结晶条件下得到的不是Ce∶LuAlO_3晶体,而是镥铝石榴石[Lu3Al2(Al O4)3]。只有急速降温才能够获得Ce∶LuAl O3晶体。退火和差热分析表明Ce∶LuAl O3晶体只存在于高温条件下,当温度下降时,它会分解成Lu3Al2(Al O4)3,Lu4Al2O9和Lu2O3。造成LuAl O3晶体在低温下结构不稳定的原因是Lu离子的半径太小,它只适应于配位数是8的石榴石结构,只有在高温下才能适应配位数是12的钙钛矿结构。Ce-doped lutetium aluminum perovskite （Ce：LuAlO3 ） crystal, which is a newly found scintillation crystal, was grown from the melting of n （Lu2O3）： n（Al2O3）= 1 ： 1 by the Czochralski method. The experimental results show that the crystal grown under the condition of slow crystallization is lutecium-aluminum garnet [Lu3 Al2 （AlO4）3 ] with a cubic structure, not Ce：LuAlO3 with a perovskite structure. Ce：LuAlO3 phase could be obtained in the samples only after quenching at a high temperature. Differential thermal analysis tests and annealing experiments show that the grown Ce：LuAlO3 phase only exists at the high temperature and it is metastable at low temperature. With the decrease of the temperature, Ce：LuAlO3 grown from melting can decompose into Lu3 Al2 （AlO4）3 phase, monoclinic phase （Lu4 Al2 O3 ） and Lu2 O3. The unstability of the Ce：LuAlO3 crystal structure at low temperature is considered to be due to the small radius of Lu ions. The Ce：LuAlO3 can be applied to garnet structure polyhedrons with the eight coordination number, and it can only be applied to perovskite structure polyhedrons with the twelve coordination number at the high temperature.

关 键 词：铝酸镥晶体 提拉法晶体生长 热稳定性 配位多面体 闪烁晶体 

分 类 号：O785[理学—晶体学]