Y_2O_2S:Eu^(3+),Mg^(2+),Ti^(4+)红色材料的制备和长余辉性能

用高温固相法制备了Y_2O_2S:Eu^(3+),Mg^(2+),Ti^(4+)红色长余辉材料,余辉时间达到1h以上,X射线衍射测量表明材料的晶体结构为Y_2O_2S。发射光谱对应了Eu^(3+)离子~5D_J(J=0,1,2,3)→~7F_J(J=0,1,2,3,4)的特征发射;激发光谱主峰位于345 um,另外在260,396,468,540 um等处也存在激发峰。对比测量了Y_2O_2S:Eu^(3+),Mg^(2+),Ti_(4+)和Y_2O_2S:Eu^(3+)的热释发光曲线,Y_2O_2S:Eu^(3+)的热释发光曲线可以拟合成3个热释发光峰的叠加:237,226,301K;而Y_2O_2S:Eu^(3+),Mg^(2+),Ti^(4+)的热释发光曲线可以拟合成5个热释发光峰的叠加:149,215,262,287,334 K,并计算了相应的陷阱能级。Ti^(4+)是引起较深陷阱能级的主要原因,Mg^(2+)起电荷补偿的作用。

Ti^(4+)的掺入对Y_2O_2S:Eu^(3+),Mg^(2+),Ti^(4+)陷阱分布和余辉性能的影响

用高温固相法制备了不同Ti4+掺杂量的红色长余辉材料Y2O2S:Eu3+,Mg2+,Ti4+,其X射线衍射分析、发射光谱和激发光谱均不受Ti4+掺杂量改变的影响.测量了Ti4+掺杂量不同的样品的热释光谱,随着Ti4+掺杂量的增加,热释光的峰值强度先增强后减弱,有了很大的变化;用PeakFit软件以一般阶动力学模型对Ti与Y2O2S的物质的量比分别为0.5%,2.5%和8.0%的样品进行了热释光曲线拟合,得出了它的单峰曲线并计算了与其对应的陷阱参数.陷阱分布表明:当Ti掺杂量为2.5%时,有利于合适深度陷阱的大量形成,从而使材料的发光和余辉性能得到了很大的提高.

EDTA络合溶胶-凝胶法制备Y_2O_2S:Eu^(3+),Mg^(2+),Ti^(4+)红色长余辉材料

采用EDTA(乙二胺四乙酸)络合溶胶-凝胶法制备了Y2O2S:Eu3+,Mg2+,Ti4+粉体。采用X射线衍射仪、扫描电子显微镜和荧光分光光度计对不同温度合成的样品性能进行测试与表征。结果表明:当硫化温度低于1 000℃时,样品为Y2O3与Y2O2S的混合相;当温度在1 050～1 100℃时,样品为纯相的Y2O2S;当温度升高到1 150℃时,再次出现Y2O3的相。硫化温度在950～1 100℃时,产物的粒径为50～300 nm。用波长为330 nm的紫外光激发样品时,626 nm处的发射对应于Eu3+的5D0-7F2跃迁。硫化温度为1 100℃时,样品的余辉时间最佳,为95 min(≥1 mcd/m2)。相比于以乙酰丙酮为络合剂的溶胶-凝胶法,EDTA络合溶胶-凝胶法制备的样品的发光性能具有较大提高。

Characterization of Y_2O_2S∶Eu ^(3+), Mg^(2+), Ti^(4+) Long-Lasting Phosphor Synthesized by Flux Method

Long-lasting phosphor Y2O2S ： Eu^3＋ , Mg^2＋ , Ti^4＋ was synthesized by a flux method and their luminescence properties were investigated. The result indicates that the unit cell parameter c is linearly increased with the increase of Eu2O3 content in Y2O2S： Eu^3＋ （0.01 ≤ x ≤0.10）. On the other hand, the change of unit cell parameter a is not linear dependence. In the Y2O2S： Eu^3 ＋ crystal structure, Eu^3＋ ions only replaced Y^3 ＋ ions＇ places in which it posited center position of c axis. With the increase of Eu2O3 content, the position of the strongest emission peak changed from 540 nm （5D1→^ 7F2 transition） to 626 nm （^5Do→^7TF2 transition）, and the maximum intensity was obtained when x = 0.09 in Y2O2S： Eu^3＋ （0.01 ≤x ≤0.10）. This is due to the environment of trivalent europium in the crystal structure of Y2O2S. Doping with Mg^2＋ or Ti^4＋. ions alone cannot get the good long-lasting afterglow effect, whereas co-doping with Mg^2 ＋ and Ti^4 ＋ ions and excited with 365 nm ultraviolet light, a strong thermoluminesence peak appeared, red and orange long-lasting phosphorescence （LLP） was also observed and the phosphorescence lasted nearly 3 h in the light perception of the dark-adapted human eye （0.32 mcd·m^-2）. Thus the LLP mechanism was analyzed.

碱土金属离子对红色长余辉材料Y2O2S∶Eu3+,M2+ (M=Mg,Ca,Sr,Ba),Ti4+纳米阵列发光性能的影响

采用溶胶凝胶模板法制备红色长余辉发光材料Y2O2S∶Eu3+,M2+(M=Mg,Ca,Sr,Ba),Ti4+纳米阵列,利用X射线衍射、扫描电子显微镜和荧光分光光度计、照度计分别研究了不同二价离子掺杂下所合成样品的物相、形貌及发光性能。结果表明:样品排列整齐有序,管径大小统一;不同的二价离子种类没有改变晶体结构和发射峰的位置,但对余辉性能有较大的影响。用324 nm波长光激发样品,由于Eu3+的5D0→7F2跃迁,最强的红色发射峰位于626 nm处;不同离子掺杂样品的余辉性能按Ba2+、Ca2+、Sr2+、Mg2+的顺序递加,其中二价离子为Mg2+时,余辉时间长达287 s(≥1 mcd/m2),表现出最佳的余辉性能。

水热法制备Y_2O_2S∶Dy^(3+),Mg^(2+),Ti^(4+)白色长余辉微纳米材料及发光性能

采用水热法制备了白色长余辉微纳米发光材料Y2O2S∶x Dy3+,Mg2+,Ti4+(x=0.5%,1.0%,1.5%,2.0%,2.5%),利用X射线粉末衍射(XRD)、扫描电镜(SEM)、激发和发射光谱、色度坐标、余辉曲线和热释光谱对样品进行表征。结果表明:煅烧后,样品的形貌为颗粒状,其粒径在150~250 nm之间;在359 nm的紫外光激发下,样品在488 nm和579 nm处有两个很强的发射峰,它们分别对应于Dy3+的蓝色跃迁(4F9/2→6H15/2)和黄色跃迁(4F9/2→6H13/2),适当比例的黄光和蓝光混合可以产生白光;当Dy3+浓度为2.0%(摩尔分数)时,样品的余辉性能最佳,用254 nm的低压汞灯照射10 min后,余辉时间可达到3600 s(≥1 mcd/m2)以上,与同样温度下高温固相法或溶胶凝胶法所制备样品的相比,其余辉性能得到了很大改善。

Optical performance study of Sr_2ZnSi_2O_7:Eu^(2+),Dy^(3+), SrAl_2O_4:Eu^(2+),Dy^(3+) and Y_2O_2S:Eu^(3+),Mg^(2+),Ti^(4+) ternary luminous fiber

In this study, down-conversion fluorescent powder of Sr2ZnSi2O7：Eu-（2＋）,Dy-（3＋）, SrAl2O4：Eu-（2＋）,Dy-（3＋） and Y2O2S：Eu-（3＋）,Mg-（2＋）,Ti-（4＋）, which were the common three primary colors materials with long afterglow, were synthesized by high temperature solid state method. The blends of rare earth（RE） luminescent materials have been of interest to reinvest the luminescent characteristics of polyethylene terephtahalate（PET） luminous fiber. The scanning electron microscopy（SEM） and an inversion fluorescence microscope were used to characterize the surface morphology and the dispersion of inclusion. Through analysis of microcosmic morphology, three typical dispersions of luminescent particles were summarized. The X-ray diffraction indicated that the phase structure of fiber samples and crystal structure of luminescence materials kept complete after prilling and spinning. From the fluorescence spectra and CIE 1931 coordinates, it could be found that different combinations of luminous fibers were desired to obtain divers colors emission luminous fiber. And the fiber samples were a light sensation which could induct different excitation wavelengths and convert it down to different colors. The afterglow decay curve and its differential curve were summarized indicating the three decay stages. The decay curve and decay rate curve showed that the contents of Sr2ZnSi2O7：Eu-（2＋）,Dy-（3＋）, SrAl2O4：Eu-（2＋）,Dy-（3＋） and Y2O2S：Eu-（3＋）,Mg-（2＋）,Ti-（4＋） had obvious influence on the afterglow of fiber samples.

Y_(2)O_(3)颗粒增强钒合金的组织及力学性能的研究

作为核聚变堆包层候选结构材料,低活化钒合金具有较好的发展前景。为了获得高强度,在钒合金(V-4Cr-4Ti)中添加0.2wt%稀土元素Y,通过真空电弧熔炼方法获得V-4Cr-4Ti-0.2Y合金,并进行了1100℃/2 h固溶处理。通过光学显微镜分析了该合金的晶粒尺寸;采用扫描电镜和能谱仪对试样的形貌和成分进行分析;利用维氏硬度仪、电子万能实验机对合金进行了硬度、强度和塑性测试。结果表明:V-4Cr-4Ti和V-4Cr-4Ti-0.2Y的晶粒平均尺寸分别为292.5、236.29μm,说明含Y的钒合金晶粒更加细化。制备的试样中存在Y,出现了明显的Y_(2)O_(3)峰。添加稀土元素Y之后,V-4Cr-4Ti的维氏硬度、屈服强度、抗拉强度和伸长率均得到了提高。

Y_(2)O_(2)SO_(4):Eu^(3+)亚微米棒的合成及发光性能

以Na_(2)SO_(4)和K_(2)SO_(4)为熔盐,采用熔盐法合成了一维Y_(2)O_(2)SO_(4):Eu^(3+)亚微米棒。应用X射线衍射、扫描电子显微镜和光谱仪等方法对合成产物的晶体结构、形貌和发光性能进行表征。考察了烧结温度、Eu^(3+)掺杂浓度对合成产物的晶体结构、形貌和发光性能的影响。结果表明,原料混合物在1100℃空气中煅烧2 h可合成纯相、表面光滑的Y_(2)O_(2)SO_(4):Eu^(3+)亚微米棒,Y_(2)O_(2)SO_(4):Eu^(3+)亚微米棒的长度大于10μm,宽度为500~800 nm。在270 nm紫外光的激发下,Y_(2)O_(2)SO_(4):Eu^(3+)亚微米棒呈红光发射,最强发射峰位于616 nm处,归属于Eu^(3+)的^(5)D_(0)→^(7)F_(2)跃迁,Y_(2)O_(2)SO_(4):Eu^(3+)亚微米棒Eu^(3+)的最佳掺杂浓度为10mol%。

高亮度长余辉蓄光型红色荧光粉的研制

简单介绍了目前国内外长余辉荧光粉的现状,简述高亮度、长余辉的红色荧光粉原材料的预处理方法;介绍该荧光粉的最佳合成工艺试验及制备工艺;给出该粉的蓄光和发光特性。

高亮度、长余辉蓄光型红色荧光粉的研制

简单介绍目前国内外长余辉荧光粉的现状,简述高亮度、长时余辉的红色荧光粉原材料的预处理方法;介绍该荧光粉的最佳合成工艺试验及制备工艺;给出该荧光粉蓄光和发光特性的测试结果。