Tb^(3+)浓度对SrMoO_4:Tb^(3+)发光性能的影响

采用溶胶-燃烧法合成了Tb3+掺杂的SrMoO4荧光粉并研究了它的发光性能。X射线衍射(XRD)显示,前驱物在750℃下灼烧3 h得到的样品为纯相的SrMoO4。样品的激发谱由一宽带和一组窄峰组成,其中激发强度较强的峰位于288 nm和375 nm。发射谱由4组窄带组成,其中最强峰位于548 nm。对于548 nm(5D4→7F5)发射峰,最佳的Tb3+掺杂摩尔分数为0.05,其浓度猝灭机理为Tb3+离子的电偶极-电偶极相互作用。当尿素用量为理论用量的3倍时,发光强度最强。最佳烧结温度为750℃,最佳烧结时间为3 h。当Tb3+摩尔分数为0.05时,样品发光的CIE色坐标为(0.279 4,0.565 2)。结果表明,Tb3+激活的SrMoO4是一种较好可应用于白光LED的紫外激发的绿光发光材料。

First Principle Study on the Influence of Sr/Ti Ratio on the Atomic Structure and Dislocation Behavior of SrTiO_(3)

Using the first principle method,we investigate the influence of Sr/Ti ratio on the atomic structure and dislocation behavior of Sr_(n+1)TinO3_(n+1)(Ruddlesden–Popper phase)and Sr_(n)Ti_(n+1)O_(3n+2)(Magnéli phase).A linear lattice expansion versus the Sr/Ti ratio exhibits in the Ruddlesden–Popper and Magnéli phases.The Ruddlesden–Popper phase has lower formation energy and superior structural stability than the Magnéli phase.The two phases show different dislocation behaviors and it is found that a possibly preferred slip system<110>{110}emerges in the two phases,and the dislocations are more likely to dissociate into partial dislocations in Magnéli phases.