热处理温度及EDTA对β-NaYF_4:Yb^(3+),Er^(3+)材料结构与性能的影响

The Effect of Heat Treatment Temperature and EDTA on Structure and Performance of β-NaYF_4: Yb^(3+),Er^(3+)

采用共沉淀法合成了Yb3+、Er3+共掺杂的NaYF4粉体,重点研究了热处理温度和螯合剂EDTA对所合成粉体的晶相、表面形貌以及上转换发光性能的影响,并利用X射线衍射、扫描电镜及荧光光谱对其结构组成、晶体表面形貌及发光性能进行了研究。结果表明:随着热处理温度的升高,NaYF4:Yb3+,Er3+粉体由立方相向六方相转变,当温度高于600℃时又从六方相逐渐转变为立方相,而且颗粒的尺寸逐渐变大,从近似球形到无规则形状;NaYF4:Yb3+,Er3+发光强度与热处理温度密切相关,热处理温度对于β-NaYF4:Yb3+,Er3+的发光性能有着重要的影响。经过600℃热处理后的粉体具有较高的发光强度;螯合剂EDTA的添加对所合成粉体的发光性能有着明显的影响,螯合剂的添加降低了其发光强度;在1 000℃以内,NaYF4:Yb3+,Er3+具有良好的热稳定性。

Ytterbium （Yb^3＋ ） and erbium （ Er^3＋ ） ions co-doped sodium yttrium fluoride was prepared by precipitation method in the presence of EDTA as a chelating agent. The research is mainly focused on the effect of EDTA and calcina- tion temperature on the powder crystal phase, surface morphology and the luminous performance. The phase composition, microstructure and property of luminescence are characterized by XRD, SEM and fluorescence spectrophotometer. The ex- perimental results showed that with the increase of heat treatment, phase transition from cubic to hexagonal of NaYF4 ： Yb^3＋ , Er^3＋ powder occurred. When the temperature reached higher than 600 ℃ , the hexagonal phase gradually trans- formed to cubic phase, and the size of the particles increased gradually, from approximately spherical to random shape ; yb^3＋ The luminous intensity of NaYF4 ： Yb^3＋, Er^3＋ is closely related to heat treatment temperature, which has an important effect on the luminous properties. NaYFa ： Yb^3＋, Er^3＋ heated at 600 ℃ shows the relative strongest upconversion（UC） luminous intensity; The powder synthesized with EDTA shows evident effect on the intensity of UC emission, and makes UC luminous intensity weaker： NaYF4 ： Yb^3＋, Er^3＋has a good thermal stabilitv below 1 000 ℃.