稀土双掺发光材料的制备与发光性能

采用溶胶-凝胶法合成了系列Li_2Eu_(4-x)(MoO_4)_7:xYb~(3+)红色荧光粉。研究结果表明Li_2Eu_(3.76)Yb_(0.24)(MoO_4)7在615 nm处发出的红光明显强于未掺杂第二稀土的Li_2Eu_4(MoO_4)_7荧光粉。Yb~(3+)离子掺杂能够将吸收的能量很好地传递给激活离子Eu~(3+),从而起到能量传递的作用。该系列荧光粉可被395 nm的近紫外光和465 nm的可见光有效激发,在615 nm处发射亮红光,对应于Eu~(3+)的~5D_0→~7F_2跃迁,其色度优于商用红粉Y_2O_2S:Eu~(2+),能够用于紫外光和蓝光芯片激发的白光LED用红色荧光粉。     

Construction of Two Inorganic-organic Hybrid Vanadogermanates Based on Di-Cd-Substituted Ge-V-O Cluster and Transition-metal Complex Bridges

Two new inorganic-organic hybrid vanadogermanates H[Cd(en)(phen)(H_2O)]-[Cd(en)(phen)]{[Cd(phen)]_2[Ge_8V_(12)O_(41)(OH)_7]}·5H_2O(1)and[Cd(dien)_2][Cd(dien)]_2{[Cd(phen)]_2-Ge_8V_(12)O_(42)(H_2O)(OH)_6}·6.5H_2O(2)(en=ethylenediamine,dien=diethylenetriamine,phen=1,10-phenanthroline)have been synthesized by hydrothermal method.Their structures were measured by single-crystal X-ray diffractions,thermogravimetric analysis,powder X-ray diffractions and infrared spectra.Structural analysis reveals that compound 1 is an infrequent dimeric structure based on di-Cd-substituted Ge-V-O cluster and transition-metal complex bridges,while compound 2 is an infinite 1-D chain constructed from di-Cd-substituted Ge-V-O clusters and dinuclear bridging complexes.Magnetic measurement indicated that both 1 and 2 exhibit antiferromagnetic behaviors.     

Sm掺杂的红色荧光粉的制备及发光性能研究

采用高温固相法合成了Ca3Gd2WO9/xSm3＋系列红色荧光材料。研究了合成样品的最佳烧结温度和时间分别为1 100℃和3 h,讨论了Sm3＋的掺杂浓度对Ca3Gd2WO9/x Sm3＋发光强度的影响,当x为1.0%（摩尔分数）时,样品的相对发光强度达到最大值。测量了荧光粉的X射线衍射谱和荧光光谱。结果表明,该样品能够被434 nm的可见光有效激发,主发射峰位593 nm附近,对应于Sm3＋的4G5/2→6H7/2跃迁,可作为白光发光LED的红色发光材料。