中文摘要：

首次采用多元醇的方法合成了GdPO4：Eu^3＋和GdPO4：Ce^3＋,Tb^3＋纳米晶，并利用X-射线衍射（XRD），傅立叶变换红外光谱（FTIR）。透射电镜（TEM），光致发光光谱（PL）及热重和差示扫描量热分析（TG-DSC）对产物进行了表征。结果表明，产物为单斜晶系独居石结构正磷酸盐；形貌为梭形，长轴600～700nm，短轴50～200nm；纳米晶在水中有良好的分散性。GdPO4：Eu^3＋水溶液在251nm激发下，发射光谱以Eu^3＋的^5Do-^7F1（592nm）磁偶极跃迁强度最大；GdPO4：Ce^3＋，Tb^3＋纳米晶水溶液的激发光谱在240—300nm处有一宽的吸收带。峰值位于262nm，为Ce^3＋离子的4f-5d跃迁吸收，发射光谱呈现Tb^3＋特征绿色发射，最强峰位于544nm。讨论了GdPO4：Ce^3＋，Tb^3＋体系中敏化发光机理，通过光谱分析证实了存在Ce^3＋→Gd^3＋→Tb^3＋的能量传递过程。

英文摘要：

GdPO4 ：Eu^3＋ and GdPO4 ：Ce^3＋ ,Tb^3＋ nanocrystals were synthesized via the polyol method firstly and characterized by X-ray diffraction （XRD）, FTIR spectrum, transmission electron microscopy （TEM）, photoluminescenee （PL） and thermal gravimetric-differential scanning calorimetry （TG-DSC）. The obtained nanocrystals were of pure monoclinic phase （monazite type） orthophosphate and the morphology was nanospindles with a size of 600-700 nm in long axis and 50-200 nm in short axis. The as-prepared nanocrystals could be welldispersed in water to form a clear colloidal solution. The colloidal solution of GdPO4：Eu^3＋ showed characteristic emission of Eu3＋, with the magnetic-dipole transition 5Do-TF1 （592 nm） being the most prominent peak. The excitation spectrum of GdPO4：Ce^3＋,Tb^3＋ showed a broad band ranging from 240-300 nm with a maximum at 262 nm, which was ascribed to 4f-5d transition of Ce^3＋, meanwhile the emission spectrum exhibited characteristic green emission of Tb^3＋, with the strongest peak located at 544 nm. The sensitizing luminescence mechanism of GdPO4 ：Ce^3＋ ,Tb^3＋ was discussed and the energy transfer from Ce^3＋ via Gd^3＋ to Tb^3＋ ions was observed in the nanocrystals.