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Sol-Gel Template Synthesis and Characterization of Lu2O3:Eu3+ Nanowire Arrays
摘要： Uniform Lu2O3:Eu3+ nanowire arrays were successfully prepared by the sol-gel process using anodic aluminum oxide (AAO) templates. The as-synthesized nanowires are homogeneous, highly ordered, and dense and have a uniform diameter of ~300 nm defined by the AAO templates. The X-ray diffraction and selected area electron diffraction results show that the Lu2O3:Eu3+ nanowires have a polycrystalline cubic structure, and the crystallite size of the Lu2O3:Eu3+ nanowires is confined by the AAO template. The nanowires within the AAO template showed good photoluminescence and X-ray-excited optical luminescence performances for Lu2O3:Eu3+. The emission peaks were attributed to the 5D0 → 7FJ transitions of Eu3+ (J = 0, 1, 2, 3).
关键词： sol-gel method,nanowire arrays,Lu2O3:Eu3+,anodic aluminum oxide (AAO)
更新于2025-09-23 15:23:52
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Fabrication and performance of Lu2O3:Eu3+ nanowire arrays with different nanowire diameters
摘要： Lu2O3:Eu3+ nanowire arrays with different nanowire diameters were successfully fabricated by sol-gel process using submicron porous anodic aluminum oxide (AAO) templates. The nanowires in each array are homogeneous and highly ordered, and have uniform diameter defined by the template. They exhibit polycrystalline with Lu2O3 cubic structure. The crystallite sizes of the Lu2O3:Eu3+ nanowires increase with the increase of the pore diameters of AAO templates and are less than that of nanopowder prepared in the same conditions due to the confinement of AAO template on the coalescence of Lu2O3:Eu3+ nanocrystallites. The Lu2O3:Eu3+ nanowire arrays within AAO templates exhibit good performances of photoluminescence and X-ray excited optical luminescence. The emission peaks can be ascribed to 5D0→7FJ transitions of Eu3+ (J = 0, 1, 2, 3). The luminescent intensities of the Lu2O3:Eu3+ nanowire arrays also enhance with the increase of the pore diameters of AAO templates. This phenomenon is not only due to the increase of the filling ratio of Lu2O3:Eu3+, but also relates to the improvement of crystallinity. The latter mechanism is further confirmed by the fluorescent decay times of Eu3+ emission in the nanowires with different diameters. It is believed that the Lu2O3:Eu3+ nanowire array can become a promising high-spatial-resolution scintillation screen used in X-ray imaging.
关键词： Lu2O3:Eu3+ nanowire array,Diameter and crystallinity,Luminescence,AAO template and sol-gel method
更新于2025-09-23 15:21:21
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lasers
摘要： The Tm,Ho:Lu2O3 crystal was grown by the optical floating zone method for the first time. The XRD pattern shows that it belongs to the cubic crystal system (Ia￣3 space group). The absorption cross-section at 796 nm is 10 21 cm2, the full width at half maximum (FWHM) is 54 nm. The emission cross-section at 2092 nm is 4.21 2. The broad fluorescence band extends to 2200 nm where almost no absorption was found. The fluoresce lifetime at 2092 nm is 3.73 ms. With the help of up-conversion spectra, the energy transfer mechanism between Tm3+ and Ho3+ ions was investigated systematically. The potential utility of the Tm,Ho:Lu2O3 crystal as tunable and ultra-short laser media at ~2.1 μm can be expected.
关键词： Lu2O3,Ho3+ ions,Crystal growth,Tm3+ ions
更新于2025-09-12 10:27:22
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Spectroscopic properties of Er:Lu2O3 crystal in mid-infrared emission
摘要： High optical quality Er3t doped Lu2O3 single crystal with optimum doping concentration was grown by Floating zone (Fz) method. The spectral properties and Judd-Ofelt (JO) analysis were reported. The emission cross-section at 2772 nm was calculated to be 2.47 ? 10?20 cm2 with FWHM of 188 nm. The fluorescence lifetime of 4I11/2 and 4I13/2 energy level was fitted to be 1.62 ms and 4.02 ms. Optimum lifetime ratio (τlow/τup) is beneficial to laser operation. Compared with reported Er3t doped crystal, the larger spectral quality factors Q and low inversion ratio P of 7 at.% Er:Lu2O3 crystal indicate that it has a favorable laser performance for 2.8 μm laser operation.
关键词： J-O theory,Er:Lu2O3,Mid-infrared,Spectroscopic properties
更新于2025-09-12 10:27:22
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Eu:Lu2O3 transparent ceramics fabricated by vacuum sintering of co-precipitated nanopowders
摘要： Europium doped lutetium oxide (Eu:Lu2O3) nanopowders were synthesized by a co-precipitation method using hydrogen carbonate (AHC) as a precipitant. Influence of the terminal pH value on properties of the Eu:Lu2O3 precursors and calcined powders was investigated. It is found that the terminal pH value has little influence on compositions of the precursors, and all the powders calcined at 1100 °C show good crystallinity. However, the terminal pH value has significant influence on morphology and agglomeration degree of both the precursors and the calcined powders. The powders are found to have the optimal dispersity with the average particle size of 68 nm when the terminal pH is 6.57. Using the nanopowders as starting materials, Eu:Lu2O3 transparent ceramics were fabricated by vacuum sintering at 1700 °C for 30 h. The ceramics prepared from the powders whose terminal pH is 6.57 were found to have the best transparency and the in-line transmittance reaches 68% at 611 nm. The influence of vacuum sintering temperatures on the microstructure and transmittance of the Eu:Lu2O3 transparent ceramics was also investigated. The Eu:Lu2O3 ceramics sintered at 1825 °C for 30 h show the highest in-line transmittance of 72% at 611 nm. The average grain size of the prepared Eu:Lu2O3 ceramics is about 454 μm and the light output of the sample is about 10 times higher than that of commercial BGO single crystal.
关键词： Vacuum sintering,Eu:Lu2O3 transparent ceramics,Terminal pH value,Co-precipitation method,Light yield,Microstructure
更新于2025-09-10 09:29:36
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Luminescence Properties of Co-doped Eu3+, Bi3+ Lu2O3/Polyvinylpyrrolidone Films
摘要： The effect of the polyvinylpyrrolidone (PVP, MW = 130,000) molar content, PVP/Lu = 1, 2.5, 4 and 5; on the photoluminescent and structural properties of sol-gel derived Lu2O3:Eu3+, Bi3+ has been analyzed. Thin hybrid films were deposited by means of the dip-coating technique on silica quartz substrates. Films deposited at 700 ?C presented a cubic structure, with non-preferential orientation, even with the presence of PVP. The photoluminescence (PL) spectrum and Comission Internationale de l’éclairage (CIE) chromaticity diagram of films revealed a reddish Eu3+ emission at 612 nm (5D0 → 7F2) with an excitation at 320 nm of the Bi ions (6s2 → 6s6p), showing a highly-effective energy transfer process form Bi3+ to Eu3+ luminescent centers. On the other hand, the color temperature of the samples is strongly dependent on the PVP content, as a consequence of the observed difference on the branching ratios of 5D0 → 7FJ transitions of europium ions. Lifetime studies present two different behaviors for the thin films: A non-exponential nature for the lower PVP contents, and a simple exponential nature for the highest PVP one, showing that the PVP tends to promote a better dissolution of segregates and, therefore, increases the lifetime of the Eu3+ emission.
关键词： co-doped Eu3+, Bi3+,photoluminescence,polyvinylpyrrolidone (PVP),Lu2O3
更新于2025-09-09 09:28:46