共沉淀法合成稀土正磷酸盐(La,Gd)PO4:RE3+(RE=Eu,Tb)及其真空紫外光谱特性

采用共沉淀法制备了稀土正磷酸盐荧光粉(La,Gd)PO4:RE3+(RE=Eu,Tb).红外光谱分析发现GdPO4的红外光谱吸收峰与LaPO4一致,只是峰位向高波数方向移动.(La,Gd)PO4:RE3+的真空紫外光谱特性研究表明,Gd3+在能量传递过程中起中间体作用.XPS研究揭示,LaPO4的价带由O2-的2p能级构成,而GdPO4的价带则是由O2-的2p能级和Gd3+的4f能级共同构成.

The Preparation of (La,Gd)PO4:RE3+ (RE=Eu, Tb) by Co-precipitation Method and Their VUV Spectroscopic Properties

(La,Gd)PO4:RE3+ (RE=Eu or Tb) phosphors were prepared by co-precipitation method. It was found that the IR spectra of LaPO4 and GdPO4 were quite similar, the difference was that both stretching frequencies and bending frequencies of GdPO4 were higher than those of LaPO4. The VUV excitation intensity of (La,Gd)PO4:RE3+ is enhanced with the increasing of Gd3+ content, implying the intermediate role of Gd3+ in energy transfer from host absorption band to RE3+. It was also found from XPS that the LaPO4 valance band was formed by the 2p level of O2-, whereas the GdPO4 valance band was composed of the 2p level of O2-and the 4f level of Gd3+, showing the differences in band structures between LaPO4 and GdPO4, which may have influence on the VUV spectroscopic properties of (La,Gd)PO4:RE3+.