摘要
利用电子衍射、X射线衍射和荧光光谱等方法研究了 L n Ba B9O16(L n=L a,Y)的结构特性 .L n Ba B9O16为单斜晶系 ,其中 L a Ba B9O16的晶胞参数 a=1.36 6 0 nm,b=0 .7882 nm,c=1.6 2 53nm,β=10 6 .15°;YBa B9O16的晶胞参数 a=1.3476 nm,b=0 .7776 nm,c=1.6 0 4 0 nm,β=10 6 .38°.荧光光谱研究表明 ,这两种化合物结构不同 ,Y3 +在 YBa B9O16结构中处于中心对称格位 ,而 L a Ba B9O16中 L a3 +的格位则无中心对称性 .Gd3 +部分取代 L a Ba B9O16∶ Eu3 +中的 L a3 +可改善 Eu3 +离子的发光性质 .L a Ba B9O16∶ Eu3 +在真空紫外区的吸收比较弱 ,这可能与硼氧比较小有关 .
Structural properties of LnBaB 9O 16 (Ln=La, Y) were investigated by means of X ray powder diffraction, electron diffraction and luminescence. These compounds crystallize in the monoclinic crystal system with lattice parameters a =1.366 0 nm, b =0.788 0 nm, c =1.625 3 nm and β =106.15° for LaBaB 9O 16 and a =1.347 6 nm, b =0.777 6 nm, c =1.604 0 nm and β = 106.38° for YBaB 9O 16 . The study of luminescence spectra of Eu 3+ doped materials reveals that the structures of these two compounds are different. The local symmetry of the rare earth ions is central symmetric in YBaB 9O 16 and non central symmetric in LaBaB 9O 16 . The emission intensity of LaBaB 9O 16 ∶Eu 3+ is enhanced by partial substitution of La 3+ with Gd 3+ . Absorption of LaBaB 9O 16 ∶Eu 3+ in the VUV region is relatively weak, which may be related to the small ratio of B∶O.
出处
《高等学校化学学报》
SCIE
EI
CAS
CSCD
北大核心
1999年第12期1832-1837,共6页
Chemical Journal of Chinese Universities
基金
国家自然科学基金!(批准号:29625101)
关键词
硼酸盐
电子衍射
X射线衍射
荧光光谱
稀土
Electron diffraction, X-ray powder diffraction, Luminescence, Borate
