Emission Of Tb3 Research Articles

Green emission from Tb-doped SrSi 2O 2N 2 phosphors under ultraviolet light irradiation

Tb-doped SrSi 2O 2N 2 phosphors with promising luminescent properties were synthesized by the conventional solid-state reaction method, characterized by powder X-ray diffraction and studied by photoluminescence excitation and emission spectra. The synthesized materials exhibited a weak blue emission and a strong green emission in the region of 400–470 nm and 480–650 nm, which are attributed to 5D 3→ 7F j ( j=5, 4, 3) and 5D 4→ 7F j ( j=6, 5, 4, 3) transitions of Tb 3+, respectively. The green emission from 5D 4→ 7F 5 at 543 nm showed the highest intensity under the optimized concentration of 0.1 mol, after which the quenching concentration became relevant. The quenching behavior of the emission of Tb 3+ was explained by the cross-relaxation of its excited state.

Luminescence switching behavior through redox reaction in Ce3+ co-doped LaPO4:Tb3+ nanorods: Re-dispersible and polymer film

Re-dispersible Tb(3+) doped LaPO(4) nanorods have been prepared using ethylene glycol (EG) as a capping agent as well as reaction medium at a relatively low temperature of 150 °C. The X-ray diffraction study reveals that all the doped samples are well crystalline with a monoclinic structure of the LaPO(4) phase. The luminescence intensity of (5)D(4)→(7)F(5) transition at 543 nm (green) is more prominent than that of (5)D(4)→(7)F(6) transition at 487 nm (blue) for all the samples. This is related to the polarizing effect from [PO(4)](3-) to the Tb(3+) site. Concentration dependent luminescence study shows that the luminescence intensity of Tb(3+) increases up to 10 at.% and decreases above this. This is due to the concentration quenching effect arising from cross relaxation among Tb(3+)-Tb(3+) ions. The results show that nanoparticles prepared in EG medium gives an enhanced luminescence compared to that prepared in water. This is attributed to the multiphonon relaxation effect from O-H groups surrounding over nanoparticles as well as the extent of increase of agglomeration among particles for samples prepared in water. Significant enhancement in the emission of Tb(3+) is also observed when Ce(3+) is used as the sensitizer in LaPO(4):Tb(3+)nanorods. The optimum concentration of Ce(3+) for maximum luminescence is found to be 7 at.% in Ce(3+) sensitized LaPO(4):Tb(3+) (5 at.%). Based on the energy transfer process from Ce(3+) to Tb(3+), the luminescence of Tb(3+) can be switched OFF and ON by performing oxidation and reduction of Ce(3+)↔Ce(4+) using KMnO(4) and ascorbic acid, respectively. The samples are re-dispersible in water, methanol and can be incorporated into polyvinyl alcohol (PVA) films. They show a dark green emission under ultraviolet radiation.

3,4,3-LI(1,2-HOPO): In vitro formation of highly stable lanthanide complexes translates into efficacious in vivo europium decorporation

The spermine-based hydroxypyridonate octadentate chelator 3,4,3-LI(1,2-HOPO) was investigated for its ability to act as an antenna that sensitizes the emission of Sm(III), Eu(III), and Tb(III) in the Visible range (Φ(tot) = 0.2-7%) and the emission of Pr(III), Nd(III), Sm(III), and Yb(III) in the Near Infra-Red range, with decay times varying from 1.78 μs to 805 μs at room temperature. The particular luminescence spectroscopic properties of these lanthanide complexes formed with 3,4,3-LI(1,2-HOPO) were used to characterize their respective solution thermodynamic stabilities as well as those of the corresponding La(III), Gd(III), Dy(III), Ho(III), Er(III), Tm(III), and Lu(III) complexes. The remarkably high affinity of 3,4,3-LI(1,2-HOPO) for lanthanide metal ions and the resulting high complex stabilities (pM values ranging from 17.2 for La(III) to 23.1 for Yb(III)) constitute a necessary but not sufficient criterion to consider this octadentate ligand an optimal candidate for in vivo metal decorporation. The in vivo lanthanide complex stability and decorporation capacity of the ligand were assessed, using the radioactive isotope (152)Eu as a tracer in a rodent model, which provided a direct comparison with the in vitro thermodynamic results and demonstrated the great potential of 3,4,3-LI(1,2-HOPO) as a therapeutic metal chelating agent.

Cycling of rare earth elements in the atmosphere in central Tokyo

Concentrations of 14 rare earth elements (REEs) in six size classes of airborne particulate matter (APM) (<0.43, 0.43-0.65, 0.65-1.1, 1.1-2.1, 2.1-11, and >11 μm) and in two different phases (suspended particulate and dissolved) in rainwater were determined by inductively coupled plasma mass spectrometry (ICP-MS). Positive Eu and Tb anomalies were observed in size-classified APM. These anomalies may be due to large emissions of Eu and Tb to the atmosphere resulting from the recent change in Japan from the use of cathode-ray tubes to plasma displays in television sets (Eu and Tb) and from the widespread use of magneto-optical disks (Tb). The light REEs were enriched in fine APM particles (diameter < 1.1 μm). Because compositions of La/Ce/Sm in fine APM (diameter < 1.1 μm) were similar to those in automobile catalyst, the light REE enrichment was attributed to automobile emissions. In contrast, the REE distribution pattern in the suspended particulate phase in rainwater was similar to that in coarse APM (diameter > 2.1 μm), and a positive Tb anomaly was observed, suggesting that coarse particles easily become trapped in rain droplets. A negative Eu anomaly was observed in the dissolved phase in rainwater, but not in APM or in the suspended particulate phase in rainwater. Unlike other REEs, Eu can exist as both bivalent and trivalent ions in nature, and Eu-selective dissolution from or adsorption onto the trapped particles of Eu might account for the negative anomaly. These results show that atmospheric REE cycling is affected by the physico-chemical properties of APM.

CsTb2F7: an efficient radioluminescent material for fiberoptic radiation detection

In this article, the feasibility of using CsTb2F7 crystals as scintillating detectors to build radioluminescent fiberoptic dosimetry (FOD) probes has been investigated for the first time. The radioluminescence (RL) efficiency of this compound has been found to be more than twice as high as that of commercial Al2O3:C detectors under excitation with gamma radiation from a 60Co source. Additionally, the intensity of the RL signal shows no dependence on the accumulated dose. Both RL and photoluminescence spectra are nearly identical, showing emission bands at 490 and 550 nm and a minor band at 600 nm, which are compatible with the characteristic emission of Tb3+. In accordance with these results, stoichiometric terbium fluoride seems to be a promising material for use as an RL sensor for FOD in radiation medicine.

Quantifying enhanced photoluminescence in mixed-lanthanide carboxylate polymers: sensitization versus reduction of self-quenching

Remarkable enhancement and quenching of photo-luminescent emissions have been found in various mixed-lanthanide carboxylate polymers. In (Eu0.1:Tb99.9)2(2,2-biphenate)3(H2O)2 the Eu emission is comparable to the Eu homo-polymer, whilst the original Tb emission is reduced by ca. 80%. Either sensitized energy transfer or the reduction of self-quenching through dilution may play a dominant role.

Mid-infrared emission characteristics and energy transfer processes in doubly doped Tm, Tb: KPb 2Br 5 and Tm, Nd: KPb 2Br 5

We present spectroscopic studies on the ∼5 μm mid-infrared emission and energy transfer properties of Tb 3+ doped KPb 2Br 5 and Nd 3+ doped KPb 2Br 5 sensitized by Tm 3+ ions. A series of co-doped Tm, Tb: KPb 2Br 5 and Tm, Nd: KPb 2Br 5 samples were prepared from purified starting materials of PbBr 2, KBr, and rare-earth bromides. Resonant excitation into the 3H 6 → 3F 4 absorption transition of Tm 3+ at ∼1.76 μm resulted in an enhanced 5 μm emission from Tb 3+ and Nd 3+ ions in Tm, Tb: KPb 2Br 5 and Tm, Nd: KPb 2Br 5, respectively. The existence of energy transfer between Tm → Tb and Tm → Nd in KPB was further evidenced by the quenching of the emission decay times of the 3F 4 → 3H 6 transition of Tm 3+ in doubly doped Tm, Tb: KPb 2Br 5 and Tm, Nd: KPb 2Br 5 compared to singly doped Tm: KPb 2Br 5.

Effect of Tb 3+ concentration and sensitization of Ce 3+ on luminescence properties of terbium doped phosphate scintillating glass

Phosphate glasses doped with different concentrations of Ce 3+ and Tb 3+ were prepared by high temperature melting method. Effects of Tb 3+ concentration and sensitization of Ce 3+ on photoluminescence and radio-luminescence properties of terbium doped phosphate glass have been investigated by absorption, excitation and emission spectroscopy. Results showed the phosphate glass exhibit high broad absorption band attribute to the allowed 4f 8–4f 75d transition of Tb 3+, which is beneficial for the 542 nm emission of Tb 3+. It is found that the emission intensity of Tb 3+ at 542 nm increased as the concentration of Tb 3+ and Ce 3+increasing. The suitable concentration of Ce 3+ and Tb 3+ in phosphate glass is 2 mol% and 10 mol% respectively, and the emission intensity of Ce 3+/Tb 3+-codoped phosphate glass at 542 nm shows 8 times stronger than that of the commercial Bi 4Ge 3O 12 (BGO) crystal at 500 nm. The phosphate glass doped with Ce 3+ and Tb 3+ ions would be potential candidates for scintillating material for static X-ray imaging.

Sol–gel preparation and characterization of uniform core-shell structured LaInO 3:Sm 3+/Tb 3+@SiO 2 phosphors

The core-shell structured LaInO 3:Ln 3+@SiO 2 (Ln 3+ = Sm 3+, Tb 3+) phosphors were realized by coating LaInO 3:Ln 3+ phosphors on the surface of silica microspheres via a modified Pechini sol–gel process. The phase, structure, morphology, and fluorescent properties of the materials were well characterized by means of X-ray diffraction (XRD), field emission scanning electron microscopy (FE-SEM), transmission electron microscopy (TEM), Fourier transform IR spectroscopy (FT-IR), photoluminescence (PL) spectra, cathodoluminescence (CL) spectra, and the kinetic decays, respectively. The results reveal that the obtained core-shell structured phosphors consist of amorphous silica core and crystalline LaInO 3:Ln 3+ shell, which keep the uniform spherical morphology of pure silica spheres with narrow size distribution. Upon excitation by ultraviolet (UV) irradiation or electron beam, the phosphors show the characteristic emission lines of Sm 3+ ( 4G 5/2– 6H 5/2,7/2,9/2, orange) in LaInO 3:Sm 3+@SiO 2 and characteristic emissions of Tb 3+ ( 5D 4– 7F 6,5,4,3, green) in LaInO 3:Tb 3+@SiO 2, respectively. This kind of phosphors may have potential applications in field emission displays (FEDs) based on their uniform shape, low-cost synthetic route, and diverse luminescent properties.

Fluorescent and Ultraviolet—Visible Spectroscopy Studies on the Antioxidation and DNA Binding Properties of Binuclear Tb(III) Complexes

Tb(III) complexes were prepared from Tb(NO(3))(3)·6H(2)O and four Schiff-base ligands derived from 8-hydroxyquinoline-2-carboxaldehyde with aroylhydrazines. X-ray crystal and other structural analyses indicate that Tb(III) and every ligand can form a binuclear Tb(III) complex with 1:1 metal-to-ligand stoichiometry and nine-coordination at the Tb(III) center. Viscosity titration experiments and fluorescent and ultraviolet-visible (UV-Vis) spectroscopy results indicate that all the Tb(III) complexes can bind to Calf thymus DNA through intercalation with the binding constants at the order of magnitude of 10(6)-10(7) M(-1), and they may be used as potential anticancer drugs, but complexes containing active phenolic hydroxy groups may have stronger antitumor activities. Antioxidation results indicate that all the Tb(III) complexes have strong abilities of scavenging hydroxyl radicals and superoxide radicals, but complexes containing active phenolic hydroxy groups show stronger scavenging effects on hydroxyl radicals and complexes containing N-heteroaromatic substituent show stronger scavenging effects on superoxide radicals. However, Tb(III) emission with these systems is not observed, for these ligands rather are quenchers and unable to sensitize this metal ion.

Lanthanide luminescence sensing of copper and mercury ions using an iminodiacetate-based Tb(III)-cyclen chemosensor

The design, synthesis and photophysical evaluation of 1.Tb.Na, a Tb(III)-cyclen-based sensor, possessing a phenyl iminodiacetate-based receptor, for the selective detection of Cu(II) and Hg(II) ions in water is demonstrated. Sensitisation of the Tb(III) 5D 4 excited state was achieved by excitation of the phenyl receptor, which in water gave rise to a characteristic time-delayed and line-like Tb(III) emission. The Tb(III) emission was shown to be pH independent over the physiological pH window. The changes in the Tb(III) emission were monitored by carrying out metal titrations using various groups I, II and transition metal ions. Of these, only the titrations of Cu(II) and Hg(II) gave rise to modulations in the Tb(III) emission; resulting in quenching in the Tb(III) emission by ca. 65% and 40%, respectively.

Fabrication of rare-earth/quantum-dot nanocomposites for color-tunable sensing applications

We developed a new fluorescent nanocomposite by using a layer-by-layer approach to link NaYF4:Ce,Tb rare-earth (RE) nanocrystals and CdSe/ZnSe semiconductor quantum dots (QDs) with opposite charges. Under ultraviolet light excitation, the nanocomposites exhibited both the green Tb emission centered at 550 nm, and the red QD emission at 650 nm. Sensing applications showed that the red QD emission was quenched by trace amount of Cu2+ (or Ag+) ions due to the ion displacement mechanism, while the green RE emission kept constant. Thus, the nanocomposites with the decreased QD/RE emission intensity ratio and changed fluorescence output color provided a visible “indicator” to detect metal ions quantificationally. In comparison with single emission materials, the dual emission nanocomposites can be a more reliable probe for various sensing applications.

Quantum size effect and emission enhancement by energy transfer in system: Nanosized SrTiO 3 and Tb(III) ions entrapped on silica support

Nanoparticles of strontium titanate, SrTiO 3, were used to enhance the luminescence emission intensity of terbium(III) ions embedded on oxide matrices. Both the optically active components were incorporated onto xerogels by impregnation of the xerogel samples immersed firstly in SrTiO 3 sol and subsequently in a solution with Tb(III). The effect related to SrTiO 3 nanoparticles of various sizes immobilized in a silica matrix influenced the band shifting and emission intensity changes of the nanostructures. A similar phenomenon is observed for emitting Tb(III) ions in the presence of nanosized SrTiO 3, if both the components are immobilized in a silica matrix. Photoluminescence studies allow describing a plausible mechanism of enhanced Tb(III) emission that could be attributed to the energy transfer from excited SrTiO 3 nanoparticles and/or silica support to Tb(III) ions.

Enhanced luminescence of Tb3 + due to efficient energy transfer fromCe3 + in ananocrystalline Lu2Si2O7 host lattice

Nanocrystalline lutetium pyrosilicateLu2Si2O7 (LPS) doped withTb3 + (LPS:Tb) orCe3 + /Tb3 + (LPS:Ce, Tb) was obtainedat 1250 °C by the reactionof nanostructured Lu2O3 and colloidal SiO2. X-ray diffraction analysis confirmed the crystallization of a single phase of LPS at the indicatedtemperature. Different concentrations of active ions allowed us to study the influence ofCe3 + co-dopingon Tb3 + emission. Tb3 + -doped LPS yields both the blue emission (J = 3, 4, 5, 6) and the green emission (J = 3, 4, 5, 6) ofTb3 + . The greenemission of Tb3 + is enhanced remarkably in both the cathodoluminescence andphotoluminescence spectra because of energy transfer fromCe3 + toTb3 + ions, both of which are present in the host lattice. Based on theoptical luminescence and luminescence excitation spectra, the optimalTb3 + doping level for maximum light output was established to be 9 mol% and the highest enhancement ofTb3 + luminescence byCe3 + co-doping was detectedusing a 1:3 ratio of Ce3 + /Tb3 + concentration. Two different crystallographic sites ofTb3 + in the LPS lattice were detected in the luminescence and excitation spectra of samples with higherTb3 + concentrations (6–9 mol%). The single-exponential decay profile of 5D4 emission for the less concentrated samples and the double-exponential decay for the higherdoping level are in agreement with this observation. Calculation of colour coordinatesshows that LPS:Ce(0.25%)Tb(3%) emits white light.

Hybrid materials of SBA-16 functionalized by rare earth (Eu 3+, Tb 3+) complexes of modified β-diketone (TTA and DBM): Covalently bonding assembly and photophysical properties

Novel mesoporous SBA-16 type of hybrids TTA-S16 and DBM-S16 were synthesized by co-condensation of modified β-diketone (TTA-Si and DBM-Si, DBM=1,3-diphenyl-1,3- propanepione, TTA=2-thenoyltrifluoroacetone) and tetraethoxysilane (TEOS) in the presence of Pluronic F127 as template, which were confirmed by FTIR, XRD, 29Si CP-MAS NMR, and N 2 adsorption measurements. Novel organic–inorganic mesoporous luminescent hybrid containing RE 3+ (Eu 3+, Tb 3+) complexes covalently attached to the functionalized ordered mesoporous SBA-16 (TTA-S16 and DBM-S16), which were designated as bpy- RE-TTA-S16 and bpy- RE-DBM-S16, were obtained by sol–gel process. The luminescence properties of these resulting materials were characterized in detail, and the results reveal that mesoporous hybrid material bpy-Eu-TTA-S16 present stronger luminescent intensities, longer lifetimes, and higher luminescent quantum efficiencies than the corresponding DBM-containing materials bpy-Eu-DBM-S16, while bpy-Tb-DBM-S16 exhibit the stronger characteristic emission of Tb 3+ and longer lifetime than the corresponding TTA-containing materials bpy-Tb-TTA-S16.

Sulfide functionalized lanthanide (Eu/Tb) periodic mesoporous organosilicas (PMOs) hybrids with covalent bond: Physical characterization and photoluminescence

Novel organic–inorganic periodic mesoporous organosilicas (PMOs) were synthesized by linking lanthanide (Tb 3+, Eu 3+) complexes to the framework of mesoporous through the modified 4-mercaptobenzoic acid (MCBA–Si) using co-condensation method in the presence of Pluronic P123 surfactant as a template. 4-mercaptobenzoic acid (MCBA) grafted to the coupling agent 3-(triethoxysilyl)-propyl isocyanate (TEPIC) was used as the precursor for the preparation of periodic mesoporous materials. The two kinds of resulting materials (denoted as Ln–MCBA–PMOs, Ln = Tb, Eu) were characterized in detail by fourier-transform infrared spectra, ultraviolet–visible diffuse reflection absorption spectra, 29Si MAS NMR spectra, small-angle X-ray diffraction, nitrogen adsorption/desorption isotherms, photoluminescence spectroscopy and luminescence decay time measurements. The results reveal that luminescent periodic mesoporous materials have high surface area, uniformity in the mesopore structure and good crystallinity. Furthermore, the mesoporous material covalently bonded Tb 3+ complex (Tb–MCBA–PMOs) exhibits the stronger characteristic emission of Tb 3+ and longer lifetime than Eu–MCBA–PMOs due to the triplet state energy of organic ligand MCBA–Si matches with the emissive energy level of Tb 3+ very well.

Tb3+，Yb3+共掺Y2O3透明陶瓷的制备及其下转换近红外发光研究

Tb³⁺，Yb³⁺共掺Y₂O₃透明陶瓷的制备及其下转换近红外发光研究

Photoluminescence Properties of NaYF[sub 4]:Tb[sup 3+],Ce[sup 3+] under VUV/UV Excitation

NaYF 4 doped with Ce 3+ or Tb 3+ or double-doped with Ce 3+ and Tb 3+ was prepared by the hydrothermal method. With the increasing reduction temperature, the hexagonal NaYF 4 was gradually replaced by cubic NaYF 4 (α-NaYF 4 ). Tb 3+ -doped α-NaYF 4 exhibited an intensive green photoluminescence under vacuum ultraviolet (VUV) or UV excitation. Although the energy transfer between Ce 3+ and Tb 3+ was not observed in the VUV region, the green emission of Tb 3+ in α-NaYF 4 was greatly improved with Ce 3+ co-doped due to the energy-transfer procedure under UV excitation.

Near-UV Excitable White Sr[sub 2]Al[sub 2]GeO[sub 7]:Ce[sup 3+],Tb[sup 3+] Phosphor for Light Emitting Diodes

A germanate gehlenite phosphor Sr 2 Al 2 GeO 7 :Ce 3+ ,Tb 3+ was synthesized by a solid-state reaction. Sr 2 Al 2 GeO 7 crystallizes as a tetragonal structure with space group P42 1 m and lattice constants of a = 7.94669(7) A and c = 5.36112(7) A. When excited under 363 nm, Sr 2 Al 2 GeO 7 :Ce 3+ , Tb 3+ exhibits a blue emission of Ce 3+ and a yellowish green emission of Tb 3+ . Combining the two emissions whose intensity is adjusted by changing the doping level of the coactivator, an optimized white light with chromaticity coordinates of (0.25, 0.29) is generated. The phosphor could be a potential white phosphor for near-UV light emitting diodes.

Spectroscopic studies of lanthanide(III) ion complexes with diethyl(phthalimidomethyl) phosphonate

Abstract Complexation and photophysical properties of complexes of lanthanide ions, Ln(III), with diethyl(phthalimidomethyl)phosphonate ligand, DPIP, were studied. Interactions between Ln(III) and DPIP were investigated using Nd(III) absorption and Eu(III) and Tb(III) luminescence (emission and excitation) spectra, recorded in acetonitrile solution containing different counter ions (NO 3 – , Cl – and ClO 4 – ). Results of the absorption spectroscopy have shown that counter ions play a significant role in the complexation of Ln(III)/DPIP complexes. Studies of luminescence spectra of Eu(III) and Tb(III) ions proved that the formation of Ln(III)/DPIP complexes of stoichiometry Ln:L=1:3 is preferred in solution. Based on the results of elemental analysis, Nd(III) absorption spectra and IR and NMR data, it was shown that the DPIP ligand binds Ln(III) ions via oxygen from phosphoryl group, forming complexes of a general formula Ln(DPIP) 3 (NO 3 ) 3 ·H 2 O, in which the NO 3 – ions are coordinated with the metal ion as bidentate ligands. Luminescent properties and energy transfer, from the ligand to Ln(III) ions in the complexes formed, were studied based on the emission and excitation spectra of Eu(III) and Tb(III). Their luminescent lifetimes and emission quantum yields were also measured.