摘要
采用采用水热法,以La(NO_3)_3·6H_2O和NaVO_3为前驱物,合成了单斜相和四方相LaVO_4。采用X射线衍射和拉曼光谱研究了pH值和退火处理对LaVO_4晶体结构和荧光性能的影响。结构表明,前驱溶液的pH值对LaVO_4晶体结构有重要影响,pH≤5.0时,生成物为单斜相M-LaVO_4。当pH≥7.0时,生成物由单斜相转变为四方相LaVO_4,较高的退火处理有助于提高其结晶质量。荧光光谱显示两种结构LaVO_4∶Eu的发射光谱均来自于Eu^(3+)的5D0→7FJ能级的辐射跃迁,但是由于晶体结构的不同,其发射光谱的形状和发光强度存在较大差异。四方相LaVO_4是一个很好的发光基质材料。
Pure monoclinic- （ M） and tetragonal- （ T） LaVO4 were prepared by hydrothermal method using La（NO3）3·6H2O and NaVO3 as starting materials. The structure and fluorescence properties of LaVO4 were characterized by XRD, Raman spectra. The results show that pH value has an significant effect on the structure of the LaVO4. Pure monoclinic LaVO4 could be obtained at pH =5. 0. Increasing the pH value can induce the polymorph transformation from monoclinic to tetragonal type. As the pH ≥7.0, pure tetragonal LaVO4 could be obtained. In addition, annealing is helpful to improve the crystal quality. The emission spectra of M- and T-LaVO4- Eu are quite different. The emission intensity of M- LaVO4- Eu is lower than that of T-LaVO4- Eu, indicating that M-LaVO4 is not a promising luminescence host material.
出处
《人工晶体学报》
EI
CAS
CSCD
北大核心
2016年第10期2446-2451,共6页
Journal of Synthetic Crystals
基金
国家自然科学基金(11404292)
关键词
LaVO4
水热法
荧光
拉曼光谱
LaV04
hydrothermal method
fluorescence
Raman spectrum
