Preparation and Luminescence Behavior of CaSiO3:Eu3+(Bi3+)

CaSiO3:Eu3 0.08Bi3 0.002 with a monoclinic perovskite structure was synthesized by using sol-gel method, and its luminescence characteristics were investigated. From the excitation spectrum, it can be seen that the main peaks located at238, 396, 415, 437 and 359 nm correspond to the charge-transfer band of Eu3 -O2- , the absorption transitions of 7F0,1→5 L6,7F0→5D3,7F1→5D3 of Eu3 ions, and 3P1→1S0 of Bi3 ions, respectively. When the samples were excited with a light of wavelength 359 or 395 nm, it can be seen from the emission spectrum that the electronic dipole transition located at 609 nm corresponding to 5D0 →7F2 of Eu3 ions was stronger than the magnetic dipole transition located at 587 nm corresponding to 5D0→7F1 of Eu3 ions, which shows that more Eu3 ions were located in nonreversion center lattices. The energy transfer from Bi3 ions to Eu3 ions in the phosphor was also discussed. The results show that Eu3 ions could be well sensitized by Bi3 ions, and the energy-transfer pattern between Bi3 ions and Eu3 ions was resonance energy transfer.     

Vacuum Ultraviolet Excited Photoluminescence Properties of Y2O2S：Eu^3＋,Bi^3＋ Phosphor

As an Hg-free lamp using phosphor, the Bi^3＋ and EH^3＋ co-doped Y2O2S phosphors were prepared and their luminescence properties under vacuum ultraviolet（VUV） excitation were investigated. The VUV photoluminescent intensity of Y2O2S：Eu^3＋ was weak, however, considerably stronger red emission at 626 nm with good color purity was observed in Y2O2S：Eu^3＋,Bi^3＋ systems. Investigation on the photoluminescence reveals that the strong VUV luminescence of Y2O2S：Eu^3＋,Bi^3＋ at 147 nm is mainly because the Bi^3＋ acts as a medium and effectively performs the energy transfer process： Y^3＋-O^2-→Bi^3＋→Eu^3＋, while the intense emission band at 172 nm is attributed to the absorption of the characteristic ^1So-^1P1 transition of Bi^3＋ and the direct energy transfer from Bi^3＋ to Eu^3＋. The Y2O2S：Eu^3＋,Bi^3＋ shows excellent VUV optical properties compared with the commercial （Y,Gd）BO3：Eu^3＋. Thus, the Y2O2S：Eu^3＋,Bi^3＋ can be a potential red VUV-excited candidate applied in Hg-free lamps for backlight of liquid crystal display.     

Rapid Synthesis and Photoluminescence Properties of Eu-doped ZnO Nanoneedles via Facile Hydrothermal Method

Eu-doped ZnO nanoneedles with different doping concentrations were prepared via the facile hydrothermal method.The crystal structure,morphology and photoluminescence property of the ZnO nanoneedles were characterized by X-ray diffraction（XRD）,scanning electron microscopy（SEM）,X-ray photoelectron spectroscopy（XPS）,photoluminescence spectroscopy（PL） and Raman spectroscopy.The results show that the europium ions are incorporated into the crystal lattice of ZnO matrix in trivalent ions.The nanoneedles are 2-3 μm in length and 100 nm in the tip diameter.PL and Raman measurements indicate that higher Eu^3＋ doping concentration may destroy the crystallization of the nanoneedles and decrease the ratio of IUV/IDLE,which is mainly due to the more defects in the doped ZnO nanoneedles.And the characteristic red emissions of Eu^3＋ ions are found by the PL spectroscopy with the Eu^3＋doping concentration increasing,which are attributed to the ^5D0→^7F0,^5D0→^7F1 and ^5D0→^7F2 transitions.     

Spectral Characteristics of LiSrBO3：Tb^3＋ Green Phosphor

LiSrBO3:Tb3+ green phosphor was synthesized by means of a solid state reaction and its spectral characteristics were studied. The emission spectrum of LiSrBO3:Tb3+ consists of four major bands at 486, 544, 595 and 620 nm under the excitation of near ultraviolet irradiation, which are originated from the 5D4→7F6, 5D4→7F5, 5D4→7F4 and 5D4→7F3 characteristic transitions of Tb3+, respectively. Monitored at 544 nm, the excitation spectrum of the phosphor extends from 220 nm to 390 nm, with the excitation peaks c...     

溶剂热合成纳米球状La2O2S：Eu^3＋荧光粉

Nano-sphere-like Eu^3 activated lanthanum oxysulfide phosphor was first synthesized directly by solvothermal method. The phosphor was characterized by XRD, TEM and PL. Photoluminescence spectra indicate that this phosphor showed three typical transitions of Eu^3 (^5Do→^7F^1,^5D0→^7F2,^5D0→^7F4). In comparison with those prepared by high temperature solid state method, photoluminescence spectrum of Eu^3 (^5D0→^7F2)-doped nano-La2O2S：Eu^3 phosphor became broader. And the reaction mechanism was also mentioned in this paper.     

Coumarin Modified Rhodamine Derivative： Fluorescent Chemosensor Selectively Recognizing Al^3＋ and Ca^2＋

A fluorescent probe with a coumarin moiety bound to rhodamine 6G hydrazide（l） was synthesized. Its sensing behavior toward various metal ions was investigated with fluorescence methods. Compound I displays different fluorescence emission responses to Al^3＋ and Ca^2＋ at the same excitation wavelength in the visible light region, while no changes occur after the addition of other metal ions. The binding ratios of the complexs of 1-Al^3＋ and 1-Ca^2＋ are both 2：1 according to the Job plot and high resolution mass spectrometer（HRMS） experiments. Moreover, emission spectrum of 1-Ca^2＋ complex and absorption spectrum of the rbodamine dyes overlap largely. When Al^3＋ was added to the 1-Ca2＋ system, calcium in complex 1-Ca2＋ can be displaced by Al^3＋, resulting in the output of another ratiometric sensing signal, which demonstrates that the 1-Ca^2＋ complex can be served as a new and effective fluorescence resonance energy transfer（FRET） donor for rhodamine derivatives.     

Electrospinning Synthesis and Photoluminescence Properties of SnO2：xEu3＋ Nanofibers

NnO2：xEu3＋（x=O, 1%, 3%, 5%, molar fraction） fibers were synthesized by electrospinning technology. The size of the as-prepared fibers is relatively uniform and the average diameter is about 200 nm with a large draw ratio. The as-prepared Eu3＋ doped SnO2 nanofibers have a rutile structure and consist of crystallitc grains with an average size of about 10 nm. A slight red shift of the A1gand Bag vibration modes and an additional peak at 288 nm were observed in the Raman spectra of the nanofibers. The energies of bandgaps of the SnO2 nanofiber with Eu doping of 1% and 3% are 2.64 eV, and the energy of bandgap is 2.94 eV with Eu doping of 5%（molar fraction）. There is only orange emission（5D0→7F1 magnetic dipole transition） for Eu doped SnO2 nanofibers, and no red emission could be observed. The orange emission upon indirect excitation splits into three peaks and the peak intensity at the excitation wavelength of 275 nm is higher than that at the excitation wavelength of 488 nm.     

Multiphoton Ionization of Monosilane

The (3 + 1) photon ionization spectra of SiH_4 have been measured. A basically continuous spectrum was recorded in laser wavelengths from 428 to 458 nm.Two vibrational progressions were found in the UV laser region of 347-392 nm, anda fine structure of the band at 363.5 nm was assigned.The fragment ions were detected by a time-offlight mass spectrometer. No parent ion SiH_4~+ was observed whereas SiH_2~+ and SiH_3~+ were the major products. The ratio of SiH_2~+/SiH_3~+ was approximately equal to that of single photon ionization at the same energy, but the fraction of Si~+ was increased. Some additional bands appeared in Si~+ spectrum in the range of 384-390 nm implicating that the increased Si~+ might be generated from SiH_2~+ and SiH~+ ions.     

High-temperature High-pressure Hydrothermal Synthesis of Dy3＋-doped YNbO4 Single Crystal and Its Luminescence Properties

Single crystal Dy3＋ doped YNbO4phosphors were prepared via a high-temperature high-pressure hydrothermal procedure. Under excitation at 270 nm, the Dy3＋-doped YNbO4 phosphor shows bright white emission, which is composed of two strong bands at 492 and 576 nm corresponding to the characteristic 4F9/2→6H15/2 and aF9/2→6H13/2 transitions of Dy3＋, respectively. The dominant band was observed at 352 nm, which corresponds to the 6H15/2→6p7/2 transition of Dy3＋. Nearly white light was achieved at 2ex 270, 310 and 388 nm and the CIE（International Commission on Illumination） values were （0.3135, 0.3421）, （0.3088, 0.3380） and （0.3146, 0.3296）, respectively.     

氧化铝对稀土有机配合物掺杂溶胶凝胶玻璃结构及发光性能的影响

Both silica glass materials singly doped with rare earth organic complex and co-doped with Al^3 were prepared by in situ sol-gel method respectively. XRD and SEM measurements were performed to verify the non-crystalline structure of the glass. The excitation spectra, emission spectra and IR spectra were measured to analyze the influence of the glass contents on the structure of the glass and the energy level of the doped Eu(IH) ions. The effect of Al^3 on the photoluminescence properties of rare earth organic complex in silica glass was investigated. The IR spectra indicated that the in situ synthesized europium complex molecule was confined to the micropores of the host and the vibration of the ligands was frozen. When Al2O3 was doped into the silica host gel, the rare earth ions in the silica network were wrapped up and dispersed by Al2O3, so the distribution of Eu(Ⅲ) complex in the host was morehomogeneous, and the luminescence intensity of ^5D0-^7F2 transition emission of the Eu^3 ions was improved. The results showed that an appropriate amount of Al^3 added to the gel glass improved the emission intensity of the complex in the silica glass, and when the content of Al2O3 reached 4 mol%, the maximum emission intensity could be obtained compared with that of other samples containing different Al2O3 contents.     

荧光粉Ba5-3x/2B4O11∶xEu3+的制备及发光性能

采用高温固相烧结法成功制备了Ba_5-3x/2B₄O₁₁∶xEu³⁺(x=0.02~0.22)荧光粉,利用XRD和SEM等对荧光粉进行了结构和形貌表征。 在激发波长为393 nm的条件下,发射峰(596、621、657和706 nm)与Eu³⁺的⁵D₀-⁷F_J(J=1,2,3,4)电子跃迁相对应,其中621 nm最强发射峰由Eu³⁺离子⁵D₀→⁷F₂电偶极跃迁造成。 文章还研究了Eu³⁺掺杂浓度对Ba_5-3x/2B₄O₁₁∶xEu³⁺发光性能的影响,结果表明,荧光粉的发光强度随着Eu³⁺掺杂量的增加呈现先增大后减小的趋势,Eu³⁺最佳掺杂量为0.16。     

磁性荧光双功能复合纳米粒子Fe3O4@SiO2@ZrO2:Tb3+的合成和表征

通过原位反应合成法成功合成了一种新型水溶性的磁性荧光复合纳米粒子Fe₃O₄@SiO₂@ZrO₂:Tb³⁺,并通过扫描电子显微镜(SEM)、X射线粉末衍射仪(XRD)、红外光谱仪(FT-IR)、磁性测试仪和荧光(PL)光谱对其形貌、尺寸、相组成、磁性和荧光性能进行了表征。 结果表明,核(Fe₃O₄@SiO₂)壳(ZrO₂:Tb³⁺)结构组成的磁性荧光复合纳米粒子具有超顺磁性,其饱和磁化强度达到36 emu/g,并且在494 nm(⁵D₄→⁷F₆)、549 nm(⁵D₄→⁷F₅)、587 nm(⁵D₄→⁷F₄)和625 nm(⁵D₄→⁷F₃)处具有4个Tb³⁺特有的荧光发射光谱带峰值。 磁性荧光双功能的复合纳米粒子在生物医学领域具有潜在的应用价值。     

2, 4, 6-三甲基苯甲酸与5, 5'-二甲基-2, 2'-联吡啶构筑的系列镧系超分子配合物的晶体结构、热分解机理和性能

Six ternary lanthanide complexes formulated as [Ln(2, 4, 6-TMBA)₃(5, 5'-DM-2, 2'-bipy)]₂ (Ln = Pr 1, Nd 2, Sm 3, Eu 4, Gd 5, Dy 6; 2, 4, 6-TMBA = 2, 4, 6-trimethylbenzoate; 5, 5'-DM-2, 2'-bipy = 5, 5'-dimethyl-2, 2'-bipyridine) have been synthesized under solvothermal conditions and characterized by single-crystal X-ray diffraction, elemental analysis, thermogravimetric analysis, etc. The results of crystal diffraction analysis show that complexes 1–6 are binuclear units, crystallizing in the triclinic Pī space group. Complexes 1–5 are isostructural, and each of the central metal ions has a coordination number of 9. The asymmetric unit of complexes 1–5 consists of one Ln³⁺, one 5, 5'-DM-2, 2'-bipy ligand, and three 2, 4, 6-TMBA^- moieties with three coordination modes: chelation bidentate, bridging bidentate, and bridging tridentate. The coordination geometry of Ln³⁺ is distorted monocapped square antiprismatic. The binuclear units of complexes 1–5 form a one-dimensional (1D) supramolecular chain along the c-axis via π–π stacking interactions between the 2, 4, 6-trimethylbenzoic acid rings. The 1D chains are linked to form a supramolecular two-dimensional (2D) sheet in the bc plane via π–π stacking interactions between the pyridine rings. Although the molecular formulae of complex 6 and complexes 1–5 are similar, the coordination environment of the lanthanide ions is different in the two cases. The asymmetric unit of complex 6 contains a Dy³⁺ ion coordinated by a bidentate 5, 5'-DM-2, 2'-bipy and three 2, 4, 6-TMBA^- ligands adopting bidentate and bridging bidentate coordination modes. The Dy³⁺ metal center has a coordination number of 8, with distorted square antiprismatic molecular geometry. The binuclear molecule of 6 is assembled into a six-nuclear unit by π–π weak staking interactions between two 5, 5'-DM-2, 2'-bipy ligands; then, adjacent six-nuclear units form a 1D chain via offset π–π interactions between 5, 5'-DM-2, 2'-bipy ligands on different adjacent units. The adjacent 1D chains are linked by C―H···O hydrogen bonding interactions to form a 2D supramolecular structure. The thermal stability and thermal decomposition mechanism of all the complexes are investigated by the combination of thermogravimetry and infrared spectroscopy (TG/FTIR) techniques under a simulated air atmosphere in the temperature range of 298–973 K at a heating rate of 10 K·min^-1. Thermogravimetric studies show that this series of complexes have excellent thermal stability. During the thermal decomposition of the complex, the neutral ligand is lost first, followed by the acid ligand, and finally, the complex is decomposed into rare earth oxides. The three-dimensional infrared results are consistent with the thermogravimetric results. The photoluminescence spectra of complex 4 show the strong characteristic luminescence of Eu³⁺. The five typical emission peaks at 581, 591, 621, 651, and 701 nm correspond to the ⁵D₀ → ⁷F₀, ⁵D₀ → ⁷F₁, ⁵D₀ → ⁷F₂, ⁵D₀ → ⁷F₃, and ⁵D₀ → ⁷F₄ electronic transitions of Eu³⁺, respectively. The emission at 621 nm is due to the electric dipole transition ⁵D₀ → ⁷F₂, while that at 591 nm is assigned to the ⁵D₀ → ⁷F₁ the magnetic dipole transition. The lifetime (τ) of complex 4 is calculated as 1.15 ms based on the equation τ = (B₁τ₁² + B₂τ₂²))/(B₁τ₁ + B₂τ₂), and the intrinsic quantum yield is calculated to be 45.1%. Further, the magnetic properties of complex 6 in the temperature range of 2–300 K are studied under an applied magnetic field of 1000 Oe.     

卤代芳香族羧酸与含氮配体合成镧系配合物的结构、热化学和荧光性质（英文）

采用室温溶液挥发法合成了五种结构新颖的镧系配合物,其结构通式为[Ln(2,4-DFBA)₃(phen)]₂ (Ln=Sm 1, Eu2, Er 3, 2,4-DFBA为2,4二氟苯甲酸的简写,phen为1,10-菲啰啉的简写),[Ln(2-Cl-6-FBA)₂(terpy)(NO₃)(H₂O)]₂ (Ln=Tb4, Dy 5, 2-Cl-6-FBA为2-氯-6-氟苯甲酸的简写, terpy为2,2’:6’2’’-三联吡啶的简写)。五个配合物可以分为两个系列,使用不同的镧系离子作为中心离子。通过X射线单晶分析,5种配合物均属于单斜晶系,空间群为P21/n。配合物1,2和配合物3虽然具有相同的分子通式,但配位方式明显不同,形成了前者为9配位的松饼型,后者是8配位的双帽三棱柱几何构型。二维面状超分子结构的形成方式也明显不同,区别在于配合物1和2通过微弱的π-π堆积作用形成。配合物4和5是同构的,结构中引入了硝酸根离子较为有趣,通过C―H···F氢键和π-π堆积作...     

Laser-excited fluorescence spectroscopy and crystal field analysis of europium(III)-doped cordierite glass

The ⁵D₀→⁷F_0-2 emission of Eu³⁺ in cordierite is reported. Fluorescence line-narrowed emission by the ⁵D₀←⁷F₀ transition was used to study local structure around the Eu³⁺ ion in cordierite glass. It was found that the Eu³⁺ ion forms quasi-molecular complexes with the non-bridging oxygen, enabling the FLN data to be accounted for in terms of a single non-random distribution of crystal field strengths.     

Atomic and molecular absorption spectra of indium in air-acetylene flame

Absorption spectra of both atomic and molecular species in the air-acetylene flame, which are produced when the aqueous solutions of indium dissolved in HNO₃, HF, HCl, HBr and HI were aspirated into the flame, have been investigated in the u.v. region. Numerous atomic absorption lines of indium have been observed in the absorption spectra. Most of these lines were previously listed only as emission lines. Those atomic lines have been ascribed to the electronic transitions from the ground states of 5p ²P_1/2⁰ and 5p ²P_3/2⁰ to the excited states such as ls ²S_1/2, md ²D_3/2, nd ²D_5/2, 4p^{2 4}P_1/2, 4p^{2 4}P_3/2 and 4p^{2 4}P_5/2, respectively, where 13 l 6 and 14 m,n 5. The molecular absorption bands for InF, InCl and InBr in the airacetylene flame have been also observed near 234 nm, 267 nm and 282 nm, respectively, as the electronic transition of ¹Σ⁺ → ¹Π₁ Those absorption bands show fine structures due to the molecular vibrations. The spectral parameters for the molecular vibrations have been obtained from the simulations of the observed spectra. The molecular absorption band for InI was not observed because of the decomposition of the molecule in the flame. In addition, the molecular absorption band for InO has been observed near 273 nm and those for NO near 205 and 215 nm.     

1.54 and 1.75 μm infrared luminescence of Y2O3:Er

A new 1.75 μm infrared emission transition of Y₂O₃:Er³⁺ is assigned to the ⁴S_3/2 → ⁴I_9/2 transition of Er³⁺ ions situated at the C₂ sites of cubic RE₂O₃ (RE = Y, Gd, Lu). The intensities of features in the 1.54 μm ⁴I_15/2–⁴I_13/2 absorption transition due to Er³⁺ at S₆ and C₂ sites are consistent with the site occupation ratio and the relative magnetic dipole–electric dipole intensity contributions of Er³⁺ at the different sites. The 1.54 μm emission lines are predominantly from Er³⁺ ions at C₂ sites. The different behaviours of the emission intensities 1.75 and 1.54 μm groups with change in Er³⁺ dopant ion concentration, preparation technique, Yb³⁺ co-doping, temperature change and different excitation line are rationalized.     

The optical spectroscopy of Ni-doped garnets

The optical spectroscopy of YAG:Ni, Zr(Si) and GSGG:Ni, Zr(Si) crystals is presented. Absorption bands of Ni²⁺ ions in octahedral and tetrahedral coordinations are observed. Comparison of experimentally observed and predicted energy levels for Ni²⁺ in both sites is made and the parameters Dq, B and C are determined. Luminescence transitions in the near-infrared, green and red are investigated and assigned to the ³T₂→³A₂, ¹T₂→³A₂ and ¹T₂→³T₂ transitions of octahedral Ni²⁺ ions. Photocoloration of the crystals indicate that part of the dopant tetrahedral nickel ions turn into the trivalent state. The absorption spectrum of Ni³⁺ ions in GSGG:Ni is analyzed.     

Preparation and Luminescence Properties of Color-tunable Single-phased LaPO4: Eu3+/Tb3+ Phosphors

A novel series of color-tunable single-phased phosphors La_1-x-yPO₄:xEu³⁺/yTb³⁺(x=0, 0.01, 0.02, 0.03, 0.04, 0.05; y=0, 0.05, 0.10, 0.15, 0.20) was synthesized via microwave-assisted co-precipitation method with diammonium hydrogen phosphate as precipitant. The morphology, crystal structure and photoluminescence properties of the as-prepared samples were characterized by means of X-ray diffraction(XRD), scanning electron microscopy(SEM) and fluorescence spectrophotometer. The results reveal that the as-synthesized samples calcined at 1100℃ display spherical morphology with uniform distribution. Upon excitation with 350 nm ultraviolet radiation, the LaPO₄:Eu³⁺/Tb³⁺ phosphors showed a green light peaking at 543 nm assigned to the characteristic ⁵D₄-⁷F₅ emission of Tb³⁺ and a red light peaking at 591 nm corresponding to the characteristic ⁵D₀-⁷F₁ emission of Eu³⁺ simultaneously. For the Eu³⁺/Tb³⁺ co-activated phosphors, Tb³⁺ acts as an efficient sensitizer to enhance the emission intensity of Eu³⁺ ions. The energy transfer mechanism and the emission color tunability of LaPO₄:Eu³⁺/Tb³⁺ have been studied. The results indicate that a color-tunable luminescence(from green to white to red) can be achieved by adjusting the Eu³⁺/Tb³⁺ doping ratio in the LaPO₄ host matrix.     

Fluorimetric determination of aminoglycoside antibiotics using lanthanide probe ion spectroscopy

The application of probe ion fluorimetry has succeeded in the microdetermination of six aminoglycoside antibiotics: neomycin, streptomycin, gentamicin, tobramycin, amikacin and kanamycin as sulfate salts in pure form and in some pharmaceutical preparations. The method is based on the reaction of Eu³⁺ ions with aminoglycosides through amino and hydroxy groups. Such interactions enhance the intensity of the 616 nm fluorescence emission of the Eu³⁺ ion. The fluorescence at 592 nm comes from a non-hypersensitive transition and is not affected by the ligand which is bound to the probe ions. The intensity ratio R, defined as I₅₉₂/I₆₁₆ was used to determine the amount of free and bound europium ions. A linear relationship between bound europium ions and aminoglycoside was found within the concentration ranges 20–100 ppm for neomycin, 5–60 ppm for streptomycin, and 10–70 ppm for gentamicin, tobramycin, amikacin, and kanamycin as sulfate salts. The percentage recoveries ranged from 99.22 to 101.07, with standard deviations ranging from ± 1.5 to ± 4.38. The relative stability constants ranged from 5 × 10³ to 2 × 10⁴. The optimum reaction conditions were studied and the results obtained compared favourably with the fluorimetric method using fluorescmine reagent.