摘要
用高温固相反应法合成了铌酸根 Nb O3- 4 和 Eu3+共掺杂的正钽酸盐化合物 Y1 - x Eux Ta1 - y Nby O4,研究了该体系在紫外光和 X射线激发下的发光性能 .研究表明 ,在紫外光激发下 ,YTa O4∶ Nb,Eu是一种比较有效的红色发光材料 .激发能可以通过 Nb O3- 4 离子传递给 Eu3+离子 .随钽酸盐中 Nb O3- 4 基团浓度的增加 ,化合物的结构从 M′型 YTa O4变成褐钇铌型 YNb O4结构 ,它的发光性质也随之改变 .
A series of Y 1- x Eu x Ta 1- y Nb y O 4 ( x =0—0.20, y =0—1.00) are synthesized by a modified solid state reaction method. When the concentration of NbO 3- 4 in yttrium tantalate is low, the structure of these systems is M′ type YTaO 4. With increasing concentration of NbO 3- 4, its structure completely changed from M′ type YTaO 4 to fergusonite YNbO 4. Under UV excitation, the emission spectra of YTaO 4∶Nb,Eu consist of two parts, the emission band between 300—450 nm is the charge transfer emission of NbO 3- 4, and the sharp line emissions in the range of 500—720 nm originate from the transition of electrons in 4 f shell of Eu 3+ . The main peak at 612.7 nm can be ascribed to the Eu 3+ 5 D 0→ 7 F 2 transition and shows a strong red emission. Fixing the concentration of Nb 5+ and Eu 3+ separately, and changing the concentration of another ions, the luminescent properties of Y 1- x Eu x Ta 1- y Nb y O 4 will change rapidly. The difference of luminescence is originated from different structures. The excitation spectra of NbO 3- 4 emission ( λ =400 nm) in YTa 0.98 Nb 0.02 O 4 is a strong excitation band peak at 235 nm. In fact, the band is composed of charge transfer excitation of TaO 3- 4 and charge transfer excitation of NbO 3- 4. The excitation spectra of Eu 3+ 5 D 0→ 7 F 2 transition emission have two parts, the sharp lines between 300—600 nm and wide band between 200—300 nm. The sharp lines originate from Eu 3+ f f electron transitions, and the wide band includes both charge transfer excitation of TaO 3- 4 and NbO 3- 4, and charge transfer excitation of Eu 3+ . The excitation spectra of NbO 3- 4 emission ( λ =400 nm) in Y 0.99 Eu 0.01 Ta 0.98 Nb 0.02 O 4 is also a strong band, in which there also exists a charge transfer excitation of TaO 3- 4 and a charge trans
出处
《高等学校化学学报》
SCIE
EI
CAS
CSCD
北大核心
2001年第1期1-5,共5页
Chemical Journal of Chinese Universities
