共查询到19条相似文献,搜索用时 78 毫秒
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将硝酸钇铕和较便宜的水溶性含硫燃烧剂溶于乙醇-水溶液,通过新的乙醇辅助燃烧法合成了一次粒径约20nm的硫氧化钇(Y2O2S:Eu)发光材料。研究结果表明:采用硫代乙酰胺作为燃烧剂时,燃烧反应产物为Y2O2S:Eu及微量的Y2O3:Eu。而采用硫脲作为燃烧剂,燃烧反应产物为Y2O3:Eu,Y2O2S:Eu和/或Y2O2SO4:Eu的混合物。利用Eu^3+离子的。D0→Fi.跃迁导致的红色发光作为荧光探针,根据其在Y2O3(λem=610nm),Y2O2S(λem1=625nm,λem2=615nm),Y2O2SO4(λem1=613,λem2=615nm)基质中的光致发光光谱和X射线发光光谱位置和强度不同,来确定生成物中Y2O3:Eu,Y2O2S:Eu,Y2O2SO4:Eu物相的组成。 相似文献
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采用微波法合成了红色长余辉发光材料Y2O2S:Eu3+,Si 4+,Zn2+,研究了微波辐射功率和加热时间对制备Y2O2S:Eu3+,Si 4+,Zn2+的影响。并且对样品进行了XRD、SEM、荧光光谱和热释光谱等表征。XRD测试表明所制备的Y2O2S:Eu3+,Si 4+,Zn2+为单相,六方晶系;荧光光谱测试表明,用λem=626nm作为监控波长,在200~400nm之间有宽的激发光谱,峰值位于325nm。而发射光谱的谱线较窄,来源于Eu3+的5 D0→7F2跃迁的发射峰627.0nm最强。其中以辐射功率为750w,反应时间为25min所制备的样品发光性能最好。 相似文献
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研究乙醇辅助燃烧法制备的纳米Ln2O2S∶Yb,Pr(Ln=Y、La)的上转换发光特性。Ln2O2S∶Yb,Pr纳米上转换发光材料在980nm激光泵浦下,呈现明亮的蓝绿色发光。Y2O2S∶Yb,Pr的发射光谱峰值为514nm,而La2O2S∶Yb,Pr的发射光谱峰值为508nm,属于Pr3+的3P0→3H4跃迁。这是由于Pr3+离子的5d轨道与4f轨道很接近,其f-f跃迁受Pr3+离子周围晶场环境影响很大,其上转换发光光谱在不同基质中有较大不同。 相似文献
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燃烧-发泡法制备不球磨SrAl2O4:Eu2+,Dy3+长余辉粉体材料 总被引:2,自引:0,他引:2
向体系内添加分散剂、燃烧剂、发泡剂和矿化剂,于低温下进行燃烧-发泡反应,一步制备了不球磨的SrAl2O4Eu2+,Dy3+长余辉粉体材料.XRD分析表明,相纯度较高,晶粒尺寸为约35.2nm.FS结果显示,产品有371.8nm、398.6nm、410.0nm和420.4nm 4个主要激发峰,发射峰位于517.2nm,余辉时间达数小时.该方法具有反应时间短,合成温度低,产物发光亮度好,不用球磨就能得到粉体的优点. 相似文献
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用硫熔法制备了系列红色蓄光材料Y2O2S∶Eu3x+(0.01≤x≤0.10)的多晶粉末样品并系统研究了其发光特性。XRD结果表明,晶胞参数c随着Eu3+含量的逐渐增大而增大,而晶胞参数a没有明显的线性变化关系,这与Y2O2S∶Eu3+的晶体结构有关。Y2O2S∶Eux3+(0.01≤x≤0.10)的激发光谱相似,在626nm发射光监控下最大激发波长约在330nm附近。在330nm激发下,随着Eu3+含量逐渐增大,发射光谱最强发射峰位置从540nm右移至626nm,观察到红色特征发射峰626nm的强度逐渐增大,在Eu3+含量为0.09时,其强度达到最大。在最佳合成条件及最佳Eu3+含量下,正在进行掺杂Mg2+和Ti4+及其发光特性的研究。 相似文献
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以Gd2O3、Eu2O3、H2SO4和NaOH为实验原料,采用水热法合成了Gd2O2SO4∶Eu3+亚微米棒。XRD和FT-IR分析表明,前驱体Gd2(OH)4SO4·nH2O通过水热合成和随后的热处理(900℃,2h)能转化成纯相Gd2O2SO4。FE-SEM显示,Gd2O2SO4粉体具有边长500~800nm、长度大于10μm的亚微米棒状结构。PL光谱分析表明,在270nm紫外光激发下,Gd2O2SO4∶Eu3+的主发射峰位于618nm,呈现红光发射,归属于Eu3+的5D0→7F2跃迁,其跃迁具有单指数衰减行为,荧光寿命为1.13ms。 相似文献
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超细Y2O3∶Eu荧光粉的制备及其阴极射线发光研究 总被引:1,自引:0,他引:1
介绍了尿素 溶胶法制备粒径为 10 0~ 2 0 0nm的超细Y2 O3 ∶Eu荧光粉的实验。对荧光粉的粒径和形貌进行了SEM分析 ,测量和分析了荧光粉的XRD谱图以及微观晶体结构 ,测量了 8kV电压下荧光粉的阴极射线发光的光谱和亮度 ,并与商品微米Y2 O3 ∶Eu荧光粉进行了比较。对实验结果进行了讨论 相似文献
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在钇铝石榴石单晶基片上用射频溅射法制取了Y2 O2 S∶Eu红色发光薄膜。利用正交试验法 ,对溅射气体 (Ar H2 S)中H2 S浓度、退火气氛中SO2 与H2 的比例、退火温度和退火时间等工艺条件进行了优化试验。给出了实验结果并对其进行了讨论。 相似文献
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Photoluminescence of Ba2SiO4 and Ca2SiO4 activated with Eu2+ was investigated at various temperatures (from 10 K to 300 K) and pressures (from ambient to 200 kbar). At ambient pressure and room temperature, under UV excitation both phosphors yielded a green emission band with maxima at 505 nm and 510 nm for Ba2SiO4 and Ca2SiO4, respectively. The energies of these bands depended on pressure; the pressure shifts were ?12:55 cm?1/kbar for Ba2SiO4:Eu2+; and ?5:59 cm?1/kbar for Ca2SiO4:Eu2+. In the case of Ca2SiO4:Eu2+, we observed additional broadband emission at lower energies with a maximum at 610 nm (orange band). The orange and green emission in Ca2SiO4:Eu2+ had different excitation spectra: the green band could be excited at wavelengths shorter than 470 nm, whereas the orange band — at wavelengths shorter than 520 nm. The pressure caused a red shift of orange emission of 7.83 cm?1/kbar. The emission peaked at 510 nm was attributed to the 4f65d→4f7(8S7=2) transition of Eu2+ in the β — Ca2SiO4:Eu2+ phase, whereas the emission peaked at 610 nm — to the γ — Ca2SiO4:Eu2+ phase. The emission of Ba2SiO4:Eu2+ peaked at 505 nm was attributed to the 4f65d→ 4f7(8S7/2) transition of Eu2+ in the β — Ba2SiO4 phase. 相似文献
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Xue Yu Xuhui Xu Hongling Yu Tingming Jiang Penghui Yang Qing Jiao Jianbei Qiu 《Materials Research Bulletin》2012,47(9):2696-2699
Persistence energy transfer between Eu2+ ions in CaAl2Si2O8:Eu2+ has been observed, which mainly due to the complexity of the system, brought about by the different crystallographic sites.With the increase of Eu2+ concentration, a persistent down-converted afterglow from blue to green was observed due to efficient persistence energy transfer from Eu1 to Eu2 which located at inequivalent sites in CaAl2Si2O8:0.19Eu2+. When some of the trapped carries are released from the traps (T1) via thermal activation, they are returned to the excited state of Eu1, and rapidly transfer their energy to Eu2, which contribute to the observation of tunable persistent color. 相似文献
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In SrO · 6Al2O3 : Eu2+ phosphor, blue Eu2+ luminescence is observed from Eu2+ on the strontium site present in the lattice. The concentration quenching process between Eu2+ ions is determined and the corresponding concentration quenching mechanism is verified as dipole-dipole interaction. The value of the critical transfer distance is calculated as 25 Å and its reliability is confirmed by using Dexter's theory on energy transfer. 相似文献
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B.S. Kim Y.H. Song D.S. Jo T. Abe K. Senthil T. Masaki K. Toda D.H. Yoon 《Materials Research Bulletin》2012,47(10):3015-3019
SiO2 added phosphors, CaAl2Si2O8:Eu2+ + xSiO2 (x = 0, 1, 2, 3, 4, 5, 6 and 13 mol) were synthesized by a novel liquid phase precursor (LPP) method. The photoluminescence properties of phosphor added by 5 mol of SiO2 showed 110% enhancement in the emission intensity compared to the CaAl2Si2O8:Eu2+ phosphor. A broad emission and excitation wavelength was observed approximately from 400 nm to 600 nm centered at 430 nm and from 280 nm to 400 nm centered at 365 nm, respectively. Photoluminescence intensity of the phosphors increased continuously by SiO2 addition up to x = 5 mol and then it decreased with further addition of SiO2. The observed photoluminescence properties of the phosphors were discussed related to their crystalline structure and morphology. 相似文献
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采用溶胶-凝胶法制备了CaAl2SiO6∶Eu2+荧光粉,利用X射线衍射仪、荧光光谱仪、热分析仪对其结构和光学性质进行了研究.结果表明,样品经1 000℃CaAl2SiO6∶Eu2+荧光粉在430 nm附近的发光峰为Eu2+中心的4f65d1(t2g)→4f7(8S7/2)跃迁;随Eu2+离子浓度的增加,样品的发光强度先增加后降低,在Eu2+浓度为0.7 mol%时达到最大;CaAl2SiO6∶Eu2+系列荧光粉的激发峰波长在280~390 nm之内,可以作为一种新型的UV-LED用三基色荧光粉. 相似文献