Contour mapping 2D and 3D-photoluminescence of Au-doped one-dimensional Eu(III) and Tb(III) hydroxide and oxide nanostructures

Au nanoparticles were embedded in one-dimensional Eu(III) and Tb(III) hydroxide and oxide nanostructures, and the Au doping effect was understood by contour mapping 2D and 3D-photoluminscecne profiles. Photoluminescence intensity was commonly quenched by dipole–dipole coupling between Au NPs and luminescent centers. The ⁵D₀→⁷F_J emission of Eu(III) was observed by a direct excitation of Eu(III), while the emission was further quenched upon annealing, and only observed by an indirect excitation. The ⁵D₄→⁷F_J emission of Tb(III) was seen before annealing. Upon annealing, the emission was totally quenched, and a broad emission peak was observed at 550 nm.     

Study of magneto-optic element as a displacement sensor

Displacement sensors are important components in many instrumentation systems, but the existing electrical based systems suffer from electromagnetic interference, noise, low response, etc. In the present paper, a magneto-optic element like Terbium Doped Glass (TDG) has been experimentally studied in double pass mode for its use as a displacement sensor. A high sensitive linear (with in ±0.54%) microdisplacement sensor with improved performance over an appreciable range of 10 mm with a resolution of 5 μm is achieved. The theoretical analysis and experimental results are reported in the paper. The experimental data have been found to be in good agreement with the theoretical study.     

On the reasons for low luminescence efficiency in combustion-made Lu2O3:Tb

Nanocrystalline Tb-doped Lu₂O₃ was prepared via a combustion route. Its low luminescence efficiency could be dramatically increased through post-fabrication heat-treatment. Infrared spectra showed that the main reason for such a behavior, typical of combustion-made phosphors, was the presence of OH-vibrations in the as-made material. The OH-groups responsible for these vibrations could be completely removed only by heating the materials to at least 1500°C. A simple alteration of the synthesis procedure to assure evaporation of water before the combustion step led to a decrease in the OH-vibration intensities, mirrored by a noticeable increase in the emission efficiency of the resultant powder.     

Optically Functional Zeolites: Evaluation of UV and VUV Stimulated Photoluminescence Properties of Ce3+‐ and Tb3+‐doped Zeolite X

The optical properties of Tb³⁺/Ce³⁺ doped zeolites are elucidated with emphasis on ultraviolet (UV) and vacuum ultraviolet (VUV) excitation and luminescence. Ce³⁺ sensitized Tb³⁺ emission with quantum yields of 85 % may be obtained at 330 nm excitation. Low absorptivity at 254 nm due to low Ce³⁺ concentrations or low Ce³⁺/Tb³⁺ ratios, which are required for the suppression of UV components, restricts their applicability as phosphors for Hg‐based discharges, e.g., in conventional fluorescent lamps. Near band edge excitation at 172 nm revealed an immediate quantum yield of 50 % enabled by a zeolite → Ce³⁺ (5d¹) → Tb³⁺ (4f⁷5d¹) energy transfer channel, which may be exploited for the down‐conversion of the Xe₂ excimer emission.     

Fluorescence Quenching Method for Determination of Cu~(2 ) with Tb-TMA System in Presence of Triton X-100

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A ratiometric fluorescent nanoprobe based on ZIF-8@AuNCs-Tb for visual detection of 2,6-pyridinedicarboxylic acid

The rapid and sensitive detection of 2,6-pyridinedicarboxylic acid(DPA),one of the main biomarkers of Bacillus anthracis,is of great significance for the screening and diagnosing of anthrax.Herein,a ratiometric fluorescent nanoprobe based on zeolite imidazolate framework-8(ZIF-8)@AuNCs-Tb was constructed by embedding both gold nanoclusters(AuNCs) and terbium ions(Tb³⁺) into ZIF-8 for highresolution visual detection of DPA.Due to the aggregation induced emission enhancement(AIE) effect...     

Characterization of luminescent hydroxyapatite@terbium complex core-shell composites using chlorobenzoic acid as ligands

Three kinds of novel hydroxyapatite@terbium complex core-shell composites were synthesized with 2-chlorobenzoic acid, 4-chlorobenzoic acid, and 2,4-dichlorobenzoic acid as the ligand, respectively. The XRD, UV/vis absorption and FT-IR results show that terbium ions are coordinated with ligands and the corresponding complexes are successfully included into composites. SEM and EDS results reveal that Tb complexes are fully and homogenously coated on the surface of hydroxyapatite (HAP) microspheres consisting of a large number of nanosized crystals. The strongest luminescence properties are obtained when 2,4-dichlorobenzoic acid is used as ligand. The study on fluorescence lifetime of composites shows that the lifetime is inversely related to emission intensity. TGA-DSC results indicate that the core-shell composites have an excellent thermal stability. Therefore, the current core-shell structure provides a cost-effective route to manufacture of biocompatible and heat-resistant highly luminescent materials.     

Magneto-optical properties of Tb0.81Ca0.19F2.81 and Tb0.76Sr0.24F2.76 single crystals

High optical quality terbium calcium fluoride (Tb_0.81Ca_0.19F_2.81) and terbium strontium fluoride (Tb_0.76Sr_0.24F_2.76) single crystals have been grown by the Czochralski method under controlled atmosphere. While both compounds present similar optical and magneto-optical properties (determined by the high concentration of Tb³⁺ ions), the lower absorption losses and high Faraday rotation exhibited by terbium calcium fluoride, compared to those of terbium strontium fluoride, lead to a notable figure of merit for Faraday isolators operating in the visible wavelength region. In particular at short wavelengths, below 500 nm, the figure of merit of terbium calcium fluoride is remarkably higher than that of the industrial standard terbium gallium garnet.     

Synthesis and optical properties of water-soluble fluoride nanophosphors co-doped with Eu and Tb

The synthesis, structure and optical properties of water-soluble fluoride nanophosphors co-doped with Eu³⁺ and Tb³⁺ are presented. Nanocrystals of NaYF₄ were synthesized via a hydrothermal microwave-assisted technique. XRD, TEM, AFM, FTIR as well as photoluminescence (PL) spectra were used to characterize the doped nanocrystals. The average size of nanocrystals, determined from XRD, AFM and TEM measurements, was ca. 28 nm. It was found that energy transfer occurs between Tb³⁺ and Eu³⁺ ions embedded in NaYF₄ matrix, both in nanocrystals dispersed in chloroform and those in aqueous solution. We demonstrate that this simple colloidal system possesses the essential features required for both energy transfer and potential application in biolabeling.     

Spectroscopic and TEM studies on poly vinyl carbazole/terbium complex and fabrication of organic electroluminescent device

Terbium acetyl salicylate complex containing 1,10-phenanthroline was synthesized. Element analysis showed that the composition of the complex was Tb(C₉O₄H₇)₃(C₁₂N₂H₈). A single layer electroluminescent device using polyvinyl carbazole doped with the terbium complex as an emitting layer was fabricated. The device showed bright green EL emission. The dispersion of the terbium complex in PVK matrix was investigated using transmission electron microscopy.