Er^3＋，Sm^3＋掺杂纳米晶体NaNbO3的合成和上转换发光研究

Synthesis and Spectroscopic Properties of Er^(3+),Sm^(3+) Doped NaNbO_3

首先用水热法合成了NaNbO3样品,然后用固相法分别合成了NaNbO3,NaNbO3:Er3+,NaNbO3:Sm3+样品,X射线衍射结果表明所制备的粉体NaNbO3(水热法200℃和固相法900℃退火),NaNbO3:Er3+(900℃退火),NaNbO3:Sm3+(900℃退火)为立方相结构,在退火温度800,950和1000℃时是正交晶系,长方体结构。该粉末在980 nm LD激发下,分别发射出中心波长约为526 nm绿色,547 nm绿色和662 nm红色(掺Er3+)、526 nm绿色,550 nm绿色和660 nm红色(掺Sm3+)的上转换荧光。探讨了Er3+,Sm3+的上转换发光机制。研究了晶体的对称性和退火温度对NaNbO3:Er3+样品上转换发光强度的影响,结果表明,随着晶体的对称性降低和退火温度的提高,NaNbO3:Er3+样品的上转换发光强度增强。

The NaNbO3 samples were prepared by hydrothermal method, and NaNbO3 ： Er3 ＋ and NaNbO3 ： Sm3＋ samples were prepared by solid state reaction method. The XRD revealed that NaNbO3 （hydrotherreal method at 200 ℃ and annealing at 900 ℃ by solid state method）, NaNbO3： Er3＋ （annealing at 900 ℃ ） and NaNbO3 ： Sm3＋ （ annealing at 900 ℃ ） had cubic structure, and they had orthogonal crystal structure when annealing temperature were 800, 950 and 1000 ℃ respectively. Under 980 nm LD excitation,the up-conversion emissions at 526, 547 and 662 nm （Er3＋ ） , 526, 550 and 660 nm （ Sm3 ＋ ） were recorded. The luminescent procedures of Er3 ＋ and Sm3＋ were discussed. The effect of annealing temperature and symmetry on luminescent properties of NaNbO3： Er3＋ samples were studied. The results showed that the up-conversion emission intensities of NaNbO3： Er3＋ samples increased with increasing annealing temperature and decreasing symmetry.