摘要
用共沉淀法与高温焙烧法制备了样品CaMoO4∶Eu3+。TG-DTA谱图表明:800℃时,样品吸收的能量最大,即形成稳定的CaMoO4∶Eu3+结构。用XRD谱图进一步分析表明:800℃时,样品CaMoO4∶Eu3+已形成CaMoO4的白钨矿结构。由于2个Eu3+取代3个Ca2+,导致了晶体产生微小的晶体缺陷,从而形成具有p-n结的半导体。经过激发和发射谱图的测试发现:这种缺陷结构不但可以使Eu3+禁戒的4f电子发生跃迁,而且可以使MoO42-的能量高效地传递给Eu3+,尤其使与MoO42-的发射特征峰(488nm)部分重叠的Eu3+(465nm)的7F0→5D2电子跃迁得到了极大的加强,进而在λex=465nm的发射谱图中,自激活荧光体MoO42-的发射强度被大大减弱甚至猝灭,而Eu3+的5D0→7F2(612nm)跃迁的红光发光强度被大大增强,使该材料成为有潜在应用价值的发光材料。
The sample CaMoO4：Eu^3＋ has been prepared with the co-precipitation method and high-temperature roasting method. TG-DTA spectra show that the energy of the samples is up to the maximum implying that it has formed stable structures at 800 ℃. XRD pattern of the sample shows that the CaMoO4：Eu^3＋, at the single phase, is a representative scheelite structure of CaMoO4. Due to three Ca^2＋ replaced by two Eu^3＋ in the cell of the sample CaMoO4： Eu^3＋, the crystal produced tiny crystal defect, so that it has the sample CaMoO4：Eu^3＋ form the semiconductor which is possessed of p-n junctions. The excitation and emission spectra of the samples are investigated and reveal that the defect structures of the sample not only enable the 4felectron of the Eu^3＋ transit, but also make energy of MoO4^2-high efficiently transfer Eu^3＋, especially the ^7F0→^5D2 electronic transition （465nm） of the Eu^3＋, with the 488 nm of MoO4^2- partly overlapped, is greatly strengthened. As a result, the emission spectra with λex=465 nm shows the emission intensity of the spontaneously activated fluorescence MoO4^2- is greatly weaken or even quenching, while the red light luminescence intensity of the ^5D0→^7F2 transition （612nm）of Eu^3＋ is greatly enhanced. The sample of CaMoO4：Eu^3＋could become a valuable luminescence material.
出处
《无机化学学报》
SCIE
CAS
CSCD
北大核心
2009年第2期350-353,共4页
Chinese Journal of Inorganic Chemistry
基金
国家自然科学基金(No.20161001)
内蒙古自然科学基金(No.200508010206)
内蒙古师范大学青年基金(No.QN06015)资助项目
