中文摘要：

采用微波辐射法合成了一系列的Ca1-xMoO4∶x Dy3＋（0〈x≤0.12）和Ca0.98（Mo O4）1-1.5y（PO4）y∶0.02Dy3＋（0≤y≤0.10）黄绿色荧光粉,分别用X射线粉末衍射仪（XRD）、扫描电子显微镜（SEM）和荧光分光光度计对荧光粉的物相结构、微观形貌、发光特性进行了分析和表征。结果表明：所制得的CaMoO4∶Dy3＋晶体结构与Ca Mo O4相似,为四方晶系、白钨矿结构。样品颗粒呈立方形,边长约为5μm,且是由尺寸约为120540 nm的类球形小颗粒组成。样品的最大激发峰位于300 nm处。发射光谱由一系列尖峰组成,最强发射峰位于572 nm处,对应于Dy3＋的4F9/2→6H13/2跃迁,发光强度随Dy3＋浓度的增加先增大后减小,当Dy3＋摩尔分数为0.02时发光强度最大,而后随Dy3＋浓度的增加,发生了浓度猝灭效应。由Dexter浓度猝灭理论知,Dy3＋浓度猝灭主要为电偶极-电偶极相互作用和Dy3＋离子间交叉弛豫造成的。在254 nm波长激发下,Ca Mo O4∶Dy3＋的色坐标集中在黄绿光区域。此外,PO3-4的掺杂有效提高了CaMoO4∶Dy3＋体系的发光亮度,PO43-的最佳掺杂量为y=0.04,此时样品的发光强度比未掺杂样品提高了约19%。

英文摘要：

A series of yellow-green emitting phosphors Ca1- xMoO4∶ x Dy3＋（ 0 〈 x≤0. 12） and Ca0. 98-（ MoO4）1- 1. 5y（ PO4）y∶ 0. 02Dy3＋（ 0≤y≤0. 10） were fabricated via microwave radiation method.The phase structure,morphology and luminescence properties of the as-fabricated samples were investigated by X-ray diffraction（ XRD）,scanning electron microscope（ SEM）,and fluorescence spectrophotometer,respectively. The results reveal that the obtained Ca MoO4∶ Dy3＋phosphor powders are well assigned to the tetragonal scheelite-type similar to that of Ca MoO4. The particles are approximately cubic in shape with the side length about 5 μm,and cubic big particle is composed by a large number of spherical-like particles with a diameter of about 120- 540 nm. The maximum excitation peak of Ca MoO4∶ Dy3＋is located at 300 nm. The emission spectrum is composed of a series of sharp peaks with the strongest emission peak at 572 nm,which is ascribed to the4F9 /2→6H13 /2transition of Dy3＋. The fluorescence intensity firstly increases with the increase of Dy3＋concentra-tion in Ca MoO4 host and then decreases. The optimum luminescence is observed when the mole fraction of Dy3＋is 0. 02. When the mole fraction of Dy3＋exceeds 0. 02,luminescence intensity reduces obviously due to the concentration quenching. The mechanism of concentration quenching is mainly caused by the electric dipole-dipole interaction and the cross relaxation between Dy3＋ions. Under254 nm excitation,the chromaticity coordinates of Ca MoO4∶ Dy3＋are concentrated in yellow-green region. In addition,the emission intensity of the Ca MoO4∶ Dy3＋system is improved effectively by the doping of anions（ PO3-4）. The optimum content（ y） is about 0. 04 and the luminescence intensity is enhanced about 19% than that of the undoped.