中文摘要：

采用燃烧法制备了不同Ln^3＋（Ln=Tb,Tm,Eu）掺杂浓度和不同粒径的Y2O3∶Ln纳米晶体粉末样品,并通过高温退火获得了相应掺杂浓度的体材料样品。测量了纳米和体材料样品的发射光谱、XRD谱并拍摄了不同粒径样品的TEM照片。研究了纳米Y2O3∶Ln晶体粉末中发光中心的浓度猝灭现象和不同发光中心之间的能量传递行为。研究发现,在Y2O3纳米晶体粉末中,Tb3：5D4→7F5和Eu^3＋：5D0→7F2发光的浓度猝灭与体材料中相似,而Tb^3＋：5D3→7F5和Tm^3＋：1D2→3H4发光的猝灭浓度明显高于体材料。这是因为纳米微晶的界面会阻止能量传递的进行,产生较强的尺寸限制效应,抑制发光材料中发光中心之间能量传递的进行,但不同类型的能量传递对粒径尺寸变化的依赖关系不同。尺寸限制效应对长程相互作用类型的能量传递（如电偶极-电偶极相互作用）的抑制作用明显,对短程相互作用类型的能量传递（如交换相互作用）的影响较小。

英文摘要：

Nano-powders Y2O3 with various particle sizes and different doping concentrations of Ln（Ln=Tb,Tm,Eu） were prepared by using a combustion technique.The bulky powders doped with concentrations corresponding to nano-powders were obtained by annealing the nano-powders at high temperature.The emission spectra,XRD spectra and TEM were used in the present study.The concentration quenching of luminescent centers and energy transfer between luminescent centers in Y2O3∶Ln nanocrystal powders were investigated.It was found that the behaviors of luminescence concentration quenching for 5D4→7F5∶Tb^3＋ and 5D0→7F2∶Eu^3＋ in nano-powders are similar to that in bulky powders.On the contrary,the quenching concentrations for 5D3→7F5∶Tb^3＋ and 1D2→3H4∶Tm^3＋ are distinctly higher than that in bulk powders.This owes to the size confinement effect： the interface of nanocrystal particles can stop a portion of the energy transfer,which happens in the bulk ones,between luminescent centers.The size confinement effect can bring different influences to the different types of energy transfer.For instance,it will restrain the energy transfer（governed by electric dipole-dipole interaction） between the ions in long distances,and will hardly affect the energy transfer（governed by exchange interaction） between the ions locating at near intervals.