掺杂Eu2+的新型锶铝复合硫氧化物红色发光材料

合成了掺杂Eu2+的新型锶铝复合硫氧化物红色发光材料Sr5Al2O7S∶Eu。用粉末X射线衍射法表征了其晶体结构,计算的晶胞参数为:单斜晶系,a=0.90748(41)nm,b=0.71029(25)nm,c=0.63021(26)nm,β=103.588(41)°,V=0.39485(23)nm。研究了其激发光谱、发射光谱和余辉光谱。发射光谱峰值位于586nm处,半宽度为50nm;激发带主要在可见区,峰值位于500nm处。讨论了Eu的添加量、基质组成、S的含量等与荧光强度的关系。     

Ce3+和Tb3+掺杂的稀土硼酸盐玻璃的发光性质

报道Ｃｅ＾３＋和Ｔｂ＾３＋掺杂的硼酸盐玻璃的合成及该系列玻璃的激发和发射光谱性质。在紫外光激发下,玻璃中的Ｃｅ＾３＋发射蓝紫光,Ｔｂ＾３＋发射有特征的绿光,在Ｃｅ＾３＋和Ｔｂ＾３＋共掺杂的体系中,可观察到Ｃｅ＾３＋强烈敏化Ｔｂ＾３＋发光的现象。分析表明,Ｃｅ＾３＋和Ｔｂ＾３＋之间存在辐射能量传递稿铲无辐射能量传递。     

镨和镱掺杂Ba2 SiO4:Eu2+荧光材料的合成与发光性能

采用高温固相反应法分别合成了变价稀土镨和镱离子掺杂的绿色荧光粉[Ba(2-n-1.5x)REx]SiO4:nEu2+ (n=0.03, RE=Pr, Yb;x=0, 0.02,0.05,0.10).结果表明: 所有合成荧光粉的激发峰均为250～400 nm的宽峰, 与近紫外LED的发射光波长相匹配.发射峰位于450～550 nm之间, 是Eu2+的5d-4f跃迁的典型发射.Pr3+和Yb3+的掺入并未改变Ba2SiO4:Eu2+的相组成, 但对荧光强度的影响大, 且与掺杂元素、掺杂量和煅烧温度相关.当掺杂Pr3+和Yb3+的量为x=0.02时, 经1150 ℃煅烧所得荧光粉的发光强度分别是未掺杂时的595%和168%.证明三价稀土离子掺杂可以导致基质中的电荷缺陷而敏化Eu2+离子的发光, 而变价稀土离子的掺杂可以大大提高电荷缺陷, 导致荧光强度的进一步提高.     

Eu（MBA）2NO3Phen配合物的发光光谱

在７７Ｋ测定了Ｅｕ（ｏ－ＭＢＡ）＿２ＮＯ＿３Ｐｈｅｎ和Ｅｕ（ｍ－ＭＢＡ）＿２ＮＯ＿３Ｐｈｅｎ配合物的激发光谱，发光光谱和时间分辨光谱。光谱数据说明由于邻甲基的位阻影响，在Ｅｕ（ｏ－ＭＢＡ）＿２ＮＯ＿３Ｐｈｅｎ配合物里存在化学环境稍有不同的两种Ｅｕ￣（３＋）格位，它们的局部对称性分别为ｃ＿２ｖ和ｃ＿１，ｃ＿２或ｃ＿ｓ。在Ｅｕ（ｍ－ＭＢＡ）＿２ＮＯ＿３Ｐｈｅｎ配合物里，仅存在一种Ｅｕ￣（３＋）格位，它类似于前一个配合物的ｃ＿２ｖ对称性的Ｅｕ￣（３＋）格位。     

稀土配合物Na3Eu（DPA）3掺杂的PMMA树脂的制备及其发光性能

稀土配合物Na3Eu(DPA)3具有良好的发光特性和热稳定性,采用加热方法将Na3Eu(DPA)3掺入PMMA树脂中,制成发光塑料树脂,并测定了其发光性能,结果表明,Na3Eu(DPA)3掺入PMMA树脂后,仍保持该稀土配合物原有的发光特性制成的Na3Eu(DPA)3-PMMA树脂复合材料具有良好的发光性能,其发光强度与Na3Eu(DPA)3掺入的含量有关,但没有线性关系。     

镨和镱掺杂Ba2SiO4∶Eu^2＋荧光材料的合成与发光性能

采用高温固相反应法分别合成了变价稀土镨和镱离子掺杂的绿色荧光粉[Ba（2-n-1.5x）REx]SiO4∶nEu^2＋（n=0.03,RE=Pr,Yb;x=0,0.02,0.05,0.10）。结果表明：所有合成荧光粉的激发峰均为250-400 nm的宽峰,与近紫外LED的发射光波长相匹配。发射峰位于450-550 nm之间,是Eu2＋的5d-4f跃迁的典型发射。Pr^3＋和Yb3＋的掺入并未改变Ba2SiO4∶Eu^2＋的相组成,但对荧光强度的影响大,且与掺杂元素、掺杂量和煅烧温度相关。当掺杂Pr^3＋和Yb3＋的量为x=0.02时,经1150℃煅烧所得荧光粉的发光强度分别是未掺杂时的595%和168%。证明三价稀土离子掺杂可以导致基质中的电荷缺陷而敏化Eu^2＋离子的发光,而变价稀土离子的掺杂可以大大提高电荷缺陷,导致荧光强度的进一步提高。     

Ca2Y8（SiO4）6O2：RE（RE=Eu,Tb）发光薄膜的制备及发光性能的研究

采用溶胶－凝胶法制备了稀土离子掺杂（Eu^3 ,Tb^3 )的氧磷灰石三元稀土硅酸盐Ca2Y8(SiO4)6O2发光薄膜。通过X射线衍射（XRD）,红外光谱（IR）,扫描电镜（SEM）等方法对薄膜的组成、结构、颗粒尺寸、形貌及厚度进行了研究,通过发光光谱对薄膜的发光性质进行了分析。XRD结果表明700℃时薄膜尚处于非晶态,800℃时已开始有Ca2Y8(SiO4)6O2的物相形成,1000℃时结晶已完全。这一点和红外光谱的结果相符。发光光谱测试表明Ca2Y8(SiO4)6O2:Eu^3 薄膜显示了很强的红光发射,并以Eu^3＋的^5D0-^7F2(616nm)超灵敏跃迁为最强一组。Ca2Y8(SiO4)6O2:Tb^3 的发射光谱由蓝光发射和绿光发射两部分组成,前者对应于^5D3-^7FJ,后者对应于^5D4-^7FJ(J=6,5,4,3),且以^5D4-^7F5(544nm)绿光发射为最强。     

SrF2晶体中Ho3+-Ho3+离子对的上转换发光研究

研究了在连续调谐以染料激光激发下,掺杂Ｈｏ＾３＋离子的ＳｒＦ２单晶中Ｈｏｌ＾３＋－Ｈｏ＾３＋对的上转换发光特性。Ｈｏ＾３＋－Ｈｏ＾３＋离子对的上转换发光主要分布于;强＾５Ｆ３→＾５Ｉ８跃迁４８０ｎｍ蓝色发射,较强＾５Ｓ２,＾５Ｆ４→＾５Ｉ８跃迁的５４０ｎｍ绿色发射。     

Na3Eu(DPA)3-PC树脂的制备及其发光性能

根据稀土有机配合物Na3Eu(DPA)3(DPS:2,6-pyridine dicarboxylic acid)的发光强和热稳定性高的特点，采用加热方法将Na3Eu(DPA)3掺入PC树脂中，制成发光塑料树脂，其发光性能结果表明，Na3Eu(DPA)3掺入PC树脂后，仍保持稀土有机配合物原有的发光特性，制成的Na3Eu(DPA)3-PC树脂复合材料具有良好的发光性能，其发光强度与稀土有机配合物Na3Eu(DPA)3掺入的比例量有关，但没有一定的线性关系。     

La2—xSrxCuO4和La2—xNdxCuO4＋y的键共价性计算

使用复杂晶体化学键理论计算了Ｌａ２－ｘＳｒｘＣｕＯ４和Ｌａ２－ｘＮｄｘＣｕＯ４＋ｙ中各键的健共价性,讨论了键性随着掺杂的变化规律,研究表明,对于２１４结构,没有发现明显的化学键性与超导温度的关系,因此２１４结构中有关超导现象产生的机理还有待于进一步研究。     

Flash photolysis in Eu2+ doped NaCl

The luminescence of NaCl:Eu under flash-lamp and N₂-laser excitation has been studied. It has been found an anomalous non-exponential luminescence decay which follows a dependence I=I₀t^m with m=1 at low (90K) and room temperatures. The observed kinetics is consistent with a tunneling mechanism involving recombination of electrons and holes (V_k) at Eu sites.     

La0.5R0.5Ba2Cu3O7,Pr0.5R0.5Ba2Cu3O7以及RBa2Cu3o7（R=稀土）的键共价性计

使用复杂晶体化学键理论计算了Ｌａ０．５Ｒ０．５Ｂａ２Ｃｕ３Ｏ７（Ｒ＝Ｐｒ,Ｎｄ,Ｓｍ,Ｅｕ,Ｇｄ,Ｄｙ,Ｙ,Ｈｏ,Ｅｒ,Ｔｍ,Ｙｂ,Ｌｕ）（Ｌａ－Ｒ１２３）,Ｐｒ０．５Ｒ０．５Ｂａ２Ｃｕ３Ｏ７（Ｒ＝Ｌａ,Ｎｄ,Ｓｍ,Ｅｕ,Ｇｄ,Ｄｙ,Ｈｏ,Ｙ,Ｅｒ,Ｔｍ,Ｙｂ,Ｌｕ）（Ｐｒ－Ｒ１２３）以及ＲＢａ２Ｃｕ３Ｏ７（Ｒ＝Ｌａ,Ｐｒ,Ｎｄ,Ｓｍ,Ｅｕ,Ｇｄ,Ｄｙ,Ｈｏ,Ｙ,Ｅｒ,Ｔｍ）（Ｒ１２３）中Ｃｕ－Ｏ键的键共价性,结果表明Ｐｒ－Ｒ１２３,Ｌａ－Ｒ１２３,以及Ｒ１２３都应具有超导性,而实验结果是Ｌａ０．５Ｐｒ０．５Ｂａ２Ｃｕ０７,Ｒ０．５,Ｐｒ０．５Ｂａ２Ｃｕ３Ｏ７（Ｒ＝Ｌａ,Ｎｄ,Ｓｍ,Ｅｕ,Ｇｄ）无超导性,产生这种矛盾的原因尚不明确,需要做进一步的研究。     

Eu3+掺杂ZMCB和ZMLB基光致发光玻璃纤维性能的研究

在发光粉废料处理中发现用高温固相反应和玻璃流股牵引方法,人工拉制了Eu3 掺杂ZnO-MgO-CdO-B2O3基质的光致发光玻璃纤维,直径为0.01～0.30 mm,长10余米.Eu3 离子613 nm的强发射归属于5D0-7F2电偶极跃迁,相对613 nm发射强度40%的591 nm发射归属于5D0-7F1磁偶极跃迁.说明Eu3 在局域环境中主要占据非对称中心格位.对不同浓度Eu3 的光衰曲线进行拟合,发现随着掺杂Eu3 浓度的增加,发光由单指数衰减变为双指数衰减.用SEM观察到玻璃纤维的表面光滑、低析晶、断口质密度高、断口贝纹呈明显沟状.并测试了发光玻璃纤维的一系列力学参数,也研究了Eu3 掺杂ZnO-MgO-La2O3-B2O3基玻璃纤维的光谱性能.     

Optical studies of Eu3+ ions doped in tellurite glass

Absorption and fluorescence spectra of Eu3+ ions doped in a tellurite glass have been recorded and analysed. Judd-Ofelt analysis has been done in order to calculate the different optical parameters such as oscillator strength, Judd-Ofelt intensity parameters, stimulated emission cross-section, transition probability, branching ratio, radiative lifetime, etc. Lifetime measurements of the 5D0 level as a function of Eu3+ concentration have been used to explore the concentration quenching process. The mechanism of quenching is found to be of a dipole-dipole type.     

Thermoluminescence studies of UV-irradiated Y2O3:Eu3+ doped phosphor

The present paper reports thermoluminescence (TL) glow curves of Eu³⁺-doped Y₂O₃ phosphor with different ultraviolet (UV) exposure times. The glow peak shows second-order kinetics of Eu³⁺-doped Y₂O₃, and corresponding kinetic parameters were evaluated using the peak shape method. Calculations of trap depth were carried out using different methods. The kinetics order, activation energy, and frequency factor were calculated. The recorded glow curve shifts towards higher intensity with longer UV exposure. The heating rate used for recording TL was 3.0 °C s^?1. Particle size and structure were verified by X-ray diffraction (XRD) pattern and morphology by scanning electron microscopy (SEM) imaging.     

Reddish-orange,neutral and warm white emissions in Eu3+, Dy3+ and Dy3+/Eu3+ doped CdO-GeO2-TeO2 glasses

Eu³⁺, Dy³⁺ and Dy³⁺/Eu³⁺ doped CdO-GeO₂-TeO₂ glasses were prepared using the melt-quenching process and analyzed by X-diffraction, Raman spectroscopy, excitation and emission spectra, and emission decay time profiles. The lack of X ray diffraction peaks revealed that all samples are amorphous. Vibrational modes associated with TeOTe and GeOGe related bonds and molecular oxygen were detected by Raman spectroscopy. The luminescence characteristics were studied upon excitations that correspond with the emission of InGaN (370–420 nm) based LEDs. The Eu³⁺ singly doped glass displayed reddish-orange global emission, with x = 0.601 and y = 0.349 CIE1931 chromaticity coordinates, upon 393 nm excitation. Neutral emission with x = 0.373 and y = 0.412 CIE1931 chromaticity coordinates and correlated color temperature (CCT) of 4400 K, was achieved in the Dy³⁺ singly doped glass excited at 388 nm. The Dy³⁺/Eu³⁺ co-doped glass exhibited warm, neutral and soft warm white emissions with CCT values of 3435, 4153 and 2740 K, under excitations at 382, 388 and 393 nm, respectively, depending mainly on the Dy³⁺ and Eu³⁺ relative excitation. The Dy³⁺ excitation bands observed in the Dy³⁺/Eu³⁺ glass by monitoring the 611 nm Eu³⁺ emission, suggest that Dy³⁺ → Eu³⁺ energy transfer takes place, despite the fact that the Dy³⁺ emission decays in the Dy³⁺ and Dy³⁺/Eu³⁺ doped glass, remain without changes. The shortening of Eu³⁺ decay in presence of Dy³⁺ was attributed to an Eu³⁺ → Dy³⁺ non-radiative energy transfer process, which according with the Inokuti-Hirayama model might be dominated through an electric quadrupole-quadrupole interaction, with efficiency and probability of 5.5% and 51.6 s⁻¹, respectively.     

固相反应制备纳米CeO2粉体

氧化铈用途广泛,用量大。目前用氧化铈作为汽车尾气净化器助催化剂,细度和纯度直接影响的净化效率,因此需要加强高纯度纳米氧化铈的研究开发。