Er3+,Er3+-Yb3+和Er3+-Na+掺杂CaF2透明陶瓷的光学性能

以Ca(NO3)2、Er(NO3)3、Yb(NO3)3、KF和NaF为原料,采用热压烧结方法制备出Er3+,Er3+-Yb3+和Er3+-Na+掺杂CaF2透明陶瓷。测试了样品室温吸收光谱和发射光谱。利用Judd-Ofelt理论分析了样品的光学性能,并对吸收光谱进行计算拟合,得到光谱参数?t (t=2,4,6),根据光谱参数?t计算出Er3+某些能级的的跃迁几率、荧光分支比、辐射寿命和品质因子,讨论并比较了Er3+-Yb3+和Er3+-Na+共掺对CaF2透明陶瓷光学性能的影响。结果表明：掺杂Yb3+和Na+改变了Er3+光谱参数;Er3+-Yb3+共掺有利于提高样品的荧光强度;Er3+-Na+共掺有利于提高荧光寿命。     

Er3+替代Bi3+对Bi2(Zn1/3Nb2/3)2O7陶瓷烧结温度的影响

研究了Er3 替代Bi3 对Bi2(Zn1/3Nb2/3)2O7系介质材料结构和性能的影响,并借助X射线、扫描电镜、Agilent4284测试仪对其相结构和介电性能进行分析.研究结果表明:经Er3 替代的BZN陶瓷样品烧结温度升高(从960℃升高到1000℃);随着Er3 替代量的增加,Bi2(Zn1/3Nb2/3)2O7系介质材料的晶粒尺寸、介电常数、介电损耗都有所变化;当替代量x=0.1时,介电性能最佳,介电常数为78.7165,介电损耗为0.00134.     

Er3+掺杂TeO2-WO3-ZnO玻璃的发光性质

制备了不同组成和掺Er3 量的TeO2 WO3ZnO(TWZ)玻璃样品 ,测量了样品的吸收光谱和 970nmLD激发下的荧光光谱、荧光寿命。对制得的Er2 O3掺杂摩尔分数为 0 .6%的玻璃样品 ,由吸收光谱测得的 1.5 μm峰值吸收截面及计算的受激发射截面分别为 0 .74～0 .77pm2 和 0 .86～ 0 .90pm2 ,且玻璃的组成对其影响很小 ;Er3 在摩尔组成为 75TeO2 2 0WO35ZnO的TWZ玻璃中具有较大的荧光发射半高宽 (fullwidthathalfmaximum ,FWHM) ,且随掺Er3 量的增加 ,Er3 1.5 μm发射荧光强度和FWHM总体呈增加趋势 ,实验得到掺Er3 量为 3 .3 4× 10 2 0 /cm3时的FWHM为 80nm。研究同时发现Er3 在TWZ玻璃中具有很好的溶解性且其浓度猝灭效应较小     

Li+掺杂对Ba(Mg1/3Nb2/3)O3∶Er3+荧光粉上转换发光性能的影响

采用溶胶凝胶法制备Li+掺杂Ba(Mg1/3Nb2/3) O3∶ Er3+荧光粉,研究了碱金属离子掺杂对Ba(Mg1/3Nb3)O3∶ Er3+荧光粉物相结构及发光特性的影响.结果 表明:Li+的引入弥补了空位缺陷,提高了稀土离子之间的能量传递效率;同时降低结构对称性,提高Er3+的4f能级跃迁概率;并且提高了荧光粉的结晶度.Li+掺杂提高了Ba(Mg1/3Nb2/3)O3∶Er3+荧光粉的上转换发光强度,当Li+掺杂浓度为3％(摩尔分数)时,上转换发光强度最高增强了4倍.     

Er3+:Yb3+:Y3Al5O12单晶中Er3+离子光谱参数的计算

采用提拉法生长出光学质量的Er3 :Yb3 :Y3Al5O12(YAG)单晶,测定了晶体的吸收光谱和上转换荧光光谱,根据Judd-Ofelt理论,计算出Er3 在YAG晶体中的强度参数Ω2=1.074 1×10-20cm2,Ω4=1.295 3×1020cm2,Ω6=0.923 8×1020cm2.由此得到部分波段跃迁的荧光分支比、辐射寿命和积分发射截面积.提出将679 nm波段的4F9/2→4I15/2跃迁作为激光输出进一步研究的新通道.     

Weakening thermal quenching to enhance luminescence of Er3+ doped β-NaYF4 nanocrystals via acid-treatment

Rare earth (RE) ions-doped luminescent nanocrystals (NCs) with numerous unique advantages have attracted tremendous interest for the wide applications from science to engineering, yet suffering from the shortcoming of thermal quenching coming from surface organic ligands. We propose utilizing a facile acid-base reaction to remove surface organic ligands introduced choosing carboxylic acids as stabilizing agent and weaken thermal quenching. The results showed that the acid-base reaction displayed an outstanding cleaning effect. After acid-treatment, most surface organic ligands were removed, and there was no influence on crystal structure and morphology of as-prepared β-NaYF₄:Er³⁺ NCs. Meanwhile, with no surface organic ligands capping, β-NaYF₄:Er³⁺ NCs preferred brighter emission after thermal treatment, including up-conversion (UC), near-infrared (NIR), and mid-infrared (MIR) emission. When calcined the acid-treated β-NaYF₄:Er³⁺ NCs in different atmosphere, such as oxygen and reducing atmosphere (15%H₂ + 85%N₂), an unexpected enhancement of all emission bands in Er³⁺ was determined under phase transformation temperature, especially in oxygen atmosphere. Furthermore, all the fluorescence lifetimes of Er³⁺ also exhibited obvious extension. Our results supposed that the β-NaYF₄:Er³⁺ NCs have promising applications in safety ink, and the acid-treatment by diluted hydrochloric acid is a general approach to remove deleterious organic ligands on NC surface further to weaken thermal quenching.     

2.7 μm Emission properties of Er3+ doped fluorozirconate glass

Fluorozirconate glass, considered as the most stable heavy metal fluoride glass and excellent host for rare earth ions, has been extensively used for 2.7 μm laser materials due to its low intrinsic loss, wide transparency window, and small phonon energy. In this paper, a novel erbium ion doped fluorozirconate glass was prepared, 2.7 μm emission properties, thermal stability and Raman spectra were investigated and the spontaneous transition probability and branching ratio were calculated and analyzed. It was found that the thermal stability was greatly improved due to the ΔT increased from 59 to 89°C after introducing YF₃ on the basis of ZBLA(ZrF₄-BaF₂-LaF₃-AlF₃). In addition, intensive 2.7 μm emission was observed and the present sample with the addition of Y³⁺ possessed larger 2.7 μm emission cross section (1.12 × 10^?20 cm²) which indicated that this kind of fluoride glasses could potentially be used as an efficient gain media in the 2.7 μm fiber laser system.     

Controlled synthesis of β-NaYF4:Yb3+/Er3+ microstructures with morphology- and size-dependent upconversion luminescence

Hexagonal NaYF₄ microcrystals with controllable morphologies and tunable sizes have been successfully synthesized by a facile hydrothermal method. The influences of the molar ratios of trisodium citrate (Cit³⁻) to Y³⁺ and pH values on the phase and morphology evolution were investigated and discussed in detail. It is found that trisodium citrate and pH value as two significant external factors play key roles in the formation of the anisotropic architectures of β-NaYF₄ microcrystals. Taking hexagonal β-NaYF₄ microprisms as a candidate, the possible formation mechanism has been proposed on the basis of time-dependent experiments. In addition, the upconversion (UC) luminescence properties of β-NaYF₄:Yb³⁺/Er³⁺ samples were systematically studied and discussed. The results reveal that the UC luminescence properties are strongly dependent on their morphologies and sizes. This study not only provides important information for shape-controlled synthesis of other complex rare earth fluoride compounds, but also gives a reference for exploration of morphology- and size-dependent UC luminescence properties.     

Effect of Er3+ substitution on the quality of Mg–Fe spinel pigments

Inorganic pigments containing erbium cations and based on the spinel structure of MgFe₂O₄ were prepared. This type of spinel compound provides pigments of red to brown colour; an increase in the content of trivalent erbium cations results in pigments of a light brown hue. The pigments displayed good resistance to sunlight but this was reduced as the content of erbium increased. Pigments prepared using mechanoactivation possessed good resistance to sunlight over a range of erbium cation content.     

Influences of La and Er on structure and properties of Bi2O3–B2O3 glass

Bi₂O₃·2B₂O₃ glasses doped with La₂O₃ and Er₂O₃ were prepared by the melting-quenching method with AR-grade oxides. IR analysis was used to investigate the glass network structure. The characteristic temperatures including the glass transition temperature (T_g), crystallization temperature (T_p), and melting temperature (T_m) were estimated by DSC. The coefficient of thermal expansion (α), mass density (D), and Vickers hardness (H_v) were also measured. The results show that the basic network structure of Bi₂O₃·2B₂O₃ glasses doped with rare-earth oxides consists of chains composed of [BO₃], [BO₄], and [BiO₆] units. La₂O₃ and Er₂O₃ act as network modifiers. As the doping concentrations of the rare-earth oxides were increased, T_g increased and α decreased, indicating that a more rigid glass was obtained. Er₂O₃ reduces the melting temperature and prevents glass crystallization. La₂O₃ contributes to the improvement of the microhardness of Bi₂O₃·2B₂O₃ glass.     

固体超强酸SO2-4/TiO2/La3+催化合成己酸乙酯

研究了以固体超强酸ＳＯ＾２－／ＴｉＯ２／Ｌａ＾３＋为催化剂,己酸和无水乙醇为原料合成己酸乙酯,并考察了影响反应的因素,结果表明,醇酸比为２．０：１,催化剂用量为０．５ｇ（己酸为０．２ｍｏｌ的情况下）,带水剂苯为１５ｍＬ,反应时间为２．０ｈ是最适宜的反应条件,酯化率达９６．８％。     

Synthesis and characterization of monodispersed BaSO4/Y2O3:Eu3+ core–shell submicrospheres

Spherical BaSO₄ particles have been coated with Y₂O₃:Eu³⁺ phosphor layers (BaSO₄/Y₂O₃:Eu³⁺) by the wet chemical method. X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), energy dipersive spectroscopy (EDS), photoluminescence spectra were utilized to characterize the BaSO₄/Y₂O₃:Eu³⁺ core–shell-structured phosphor particles. The obtained core–shell phosphors consist of well dispersed submicron spherical particles with narrow size distribution. XRD result shows that no reaction occurred between the BaSO₄ cores and the Y₂O₃:Eu³⁺ shells even after annealing at 1400 °C. TEM and EDS results show that BaSO₄ particles are well coated with the shell of Y₂O₃:Eu³⁺. The BaSO₄/Y₂O₃:Eu³⁺ core–shell particles show a red emission corresponding to ⁵D₀?⁷F₂ of Eu³⁺ under the excitation of ultraviolet.     

固体超强酸SO2-4/TiO2/La3+催化合成氯乙酸乙酯

以稀土固体超强酸SO2-4/TiO2/La3+为催化剂,氯乙酸与乙醇为原料合成氯乙酸乙酯.研究了氯乙酸与乙醇的摩尔比、催化剂用量、环己烷的用量、反应时间诸因素对产品收率的影响.结果表明SO2-4/TiO2/La3+是合成氯乙酸乙酯的良好催化剂,适宜的反应条件如下氯乙酸与乙醇的摩尔比为1∶3.0,催化剂的用量0.8 g,环己烷用量15 mL,反应2.0 h,氯乙酸乙酯的收率可达92.7%.     

Facile synthesis of an up-conversion luminescent and mesoporous Gd2O3 : Er3+@nSiO2@mSiO2 nanocomposite as a drug carrier

In this paper, we report the facile synthesis of a bifunctional inorganic nanocomposite which is composed of core-shell structured mesoporous silica coated with up-conversion Gd2O3?:?Er3+ particles. X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), N2 adsorption/desorption, and photoluminescence (PL) spectra were used to characterize the samples. The results indicate that the nanocomposite with general 50 nm shell thickness and 300 nm core size shows typical ordered mesoporous characteristics (2.3 nm) and has spherical morphology with smooth surface and narrow size distribution. The bifunctional system shows unique green up-conversion emission under 980 nm NIR laser excitation even after loading with drug molecules. In addition, biocompatibility tests on L929 fibroblast cells using an MTT assay reveals low cytotoxicity of the system. Drug release tests suggest that the nanocomposite has a controlled drug release property with ibuprofen (IBU) as the model drug. Interestingly, the up-conversion emission intensity of the bifunctional carrier increases with the released amount of model drug, thus allowing the release process to be monitored and tracked by the change of up-conversion luminescence intensity. This composite can potentially act as a functional drug carrier system.     

A2B2O7(A=Ln3+,B=Zr4+,Hf4+Ti4+Ce4+)型透明陶瓷研究进展

A₂B₂O₇型化合物具有高熔点、高密度和高折射率等特点,在照明材料、航空材料、医疗成像、磁光材料等领域具有潜在应用价值。随着陶瓷制备工艺的进步,透明陶瓷的光学、力学和热学等性能不断提升使A₂B₂O₇型透明陶瓷受到越来越多研究者的关注,本文介绍了一些A₂B₂O₇型透明陶瓷的制备工艺、性能参数和其潜在的应用价值。     

Li2SrSiO4:Eu2+,Tb3+中Eu2+和Tb3+的发光特性和能量传递

用高温固相法在N2/H2=95/5(v/v)还原气氛下合成了Li2SrSiO4:Eu2+,Tb3+荧光粉发光材料,通过荧光光谱研究其发光特性,并从理论上探讨了Eu2+与Tb3+之间的能量转移类型。结果表明:该发光材料主发射峰值550nm,与Eu2+在4f7-4f65d1产生跃迁有关;通过掺杂,共存于Li2SrSiO4基质中的Tb3+通过电多级相互作用将能量传递给Eu2+;在500~650nm范围内对Eu2+具有很强的敏化作用,使其在主发射峰550nm的发射强度显著增强;当名义化学组成为Li2Sr0.995SiO4:0.005Eu2+,0.010Tb3+时,发光强度为最佳。     

水热法制备的六方相NaYF4:Er3+,Dy3+荧光粉的吸收光谱

用水热法制备了六方相NaYF4:Er3+,Dy3+荧光粉.通过在NaYF4:Er3+中共掺Dy3+,拓宽上转换荧光粉的吸收峰,以增加太阳能电池在红外光谱区的吸收范围.通过X射线衍射和分光光度计检测和分析了共掺Dy3+对荧光粉的晶体结构和晶格缺陷的影响以及拓宽荧光粉在红外光谱区的吸收范围.结果表明:共掺Dy3+后,晶胞产...     

YVO4:Er3+/Yb3+纳米纤维的静电纺丝制备及表征

实验采用静电纺丝技术和高温煅烧法结合制备YVO_4∶Er~(3+)/Yb~(3+)纳米纤维,利用X-射线衍射(XRD)、扫描电镜(SEM)、透射电镜(TEM)对其物相结构、尺寸与形貌进行了基本的表征。并系统地研究了YVO_4∶Er~(3+)/Yb~(3+)纳米纤维的上转换发光性能。结果表明,YVO_4∶Er~(3+)/Yb~(3+)纳米纤维的红色发射与绿色发射,均随激光工作电流强度的增大而增大,都随着温度的升高呈现单调下降趋势。     

Cs3Lu2Br9晶体中Er3+的配位场能级计算

在C3v点群对称场中,运用双层点电荷配位场 (DSCPCF)模型和点电荷(PCF)模型计算了Cs3Lu2Br9晶体中Er3+的配位场微扰能级,对55个配位场能级计算的均方根偏差分别是19.68 cm-1和26.37 cm-1,说明双层点电荷模型能更好地拟合实验能级.     

稀土固体超强酸SO2-4/TiO2/La3+催化合成丁酸乙酯

研究了以固体超强酸ＳＯ４＾２－／ＴｉＯ２／Ｌａ＾３＋为催化剂,丁酸和无水乙醇为原料合成丁酸乙酯,并考察了影响反应的因素。结果表明,醇酸摩尔比为２．０：１,催化剂用量的０．５ｇ（丁酸为０．２ｍｏｌ的情况下）,带水剂苯为１５ｍＬ,反应时间为２．０ｈ,是最适宜的反应条件,酯化率达９５．６％。