共查询到20条相似文献,搜索用时 78 毫秒
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通过收敛法合成了2种不同树枝状8-羟基喹啉配体,产物通过核磁共振(NMR)和红外(IR)进行表征;并通过荧光光谱对树枝状8-羟基喹啉配体及Zn(Ⅱ)金属配合物的性能进行研究,结果表明这些配体和Zn(Ⅱ)配合物均能溶于常见的溶剂,树枝状修饰使荧光强度变大,树枝状结构的外围官能团影响荧光性质;树枝状8-羟基喹啉锌的荧光出现明显的红移,有望在有机电致发光材料领域中得到广泛应用。 相似文献
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Piperidine-4-carboxylic acid (PPCA) functionalized Fe3O4 nanoparticles as a novel organic–inorganic hybrid was fabricated and characterized by XRD, FT-IR, VSM, and TEM techniques. Its detailed electrical properties are also presented. Composition was determined as Fe3O4, while particles were observed to have spherical morphology. VSM measurement proved the super-paramagnetic property of the as synthesized nanocomposite. ac and dc conductivity measurements indicated semiconductor characteristics and changing trends with temperature because of reorganization of the nanocomposite. dc conductivity is strongly temperature dependent and is classified into three regions. Analysis of the real and imaginary parts of the permittivity of nanocomposite showed the ionic polarization mechanism consisting of ionic conductivity and interfacial polarization. 相似文献
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S. Gowri T. Uma Devi S. Alen D. Sajan C. Surendra Dilip G. Vinitha 《Journal of Materials Science: Materials in Electronics》2018,29(23):19710-19723
A semi-organic nonlinear optical material phosphoric acid pyridine-1-ium-2-carboxylate (PAPC) crystal has been synthesized and grown. Vibrational spectral analysis and NMR spectral analysis has been carried out. Mechanical studies on the grown crystal has been performed which disclose the material belongs to soft materials category. The thermal behaviour of the grown crystal has been investigated by thermogravimetric and differential thermal analysis. UV–Visible spectral analysis has been carried out which reveals that the grown crystal is transparent in the entire visible region with the lower cut-off wavelength of 298 nm and the derived optical constant attests the suitability of this material for non-linear optical applications. The third order nonlinearity has been studied by z-scan method and the enhanced third-order nonlinearity shows PAPC is a potential material for device applications. Second harmonic generation efficiency has been studied by Kurtz and Perry powder test and is found as 0.14 times greater than the KDP. 相似文献
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Well-crystalline SnO(2) nanorods have been synthesized successfully via a lithium-assisted solution-phase method. The structural and optical properties of the SnO(2) nanorods were investigated using x-ray powder diffraction, transmission electron microscopy, high-resolution transmission electron microscopy, and infrared, Raman and photoluminescence spectroscopy. The experimental results show that lithium addition plays a critical role in the formation of SnO(2) nanorods, and the correlation between the surface energy change and morphological evolution of this material is also discussed. This approach provides an economically viable route for large-scale synthesis of this nanostructured material. 相似文献
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Centimeter-sized optical quality plate-like PbB4O7 crystals have been grown by Czochralski method. The fundamental absorption edge has been found at 237 nm (corresponding bandgap 5.75 eV) with the distinct sideband protruding up to 300 nm. The crystals are well faceted with the (1 0 0), (0 1 0) and (1 0 1) planes, (1 0 0) surfaces being mostly developed. The etching in diluted nitric acid (5 wt.%) at the temperature of 90 °C have been used to reveal the defect structure and remove melt residuals. The (1 0 0) surface shows the presence of etching pits and twin boundaries. The Kikuchi line pattern and developed microrelief with the roughness of ∼8 nm have been observed by RHEED and AFM, respectively. 相似文献
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甘氨酸燃烧法合成Sr2CeO4及其发光性质研究 总被引:2,自引:0,他引:2
为制备具有优良性能的蓝色荧光粉,首次采用甘氨酸-硝酸盐燃烧法合成了Sr2CeO4,利用热重-差热分析仪、X射线粉末衍射仪、扫描电镜等技术对其形成过程、物相结构、形貌粒度、发光性质进行了研究.结果表明:燃烧后的前驱物经800℃焙烧已有目标产物Sr2CeO4生成,1100℃时可得到较纯正交晶系的Sr2CeO4相.颗粒的形貌为不规则球形,平均粒径在80 nm左右.发光性质研究表明:Sr2CeO4荧光粉的激发光谱是宽带双峰结构,此宽带属于Ce4+的电荷迁移带,两个峰分别位于305 nm和348 nm,后者为主峰.用348 nm紫外光激发样品,发出明亮的蓝光,其发射光谱也是一个宽带,最大峰位于470 nm,此峰属于Ce4+的f→t1g跃迁.发光强度在800~1100℃随温度升高而增强. 相似文献
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A. I. Zaitsev A. S. Aleksandrovskii A. V. Zamkov A. M. Sysoev 《Inorganic Materials》2006,42(12):1360-1362
We have measured the second-order nonlinear optical susceptibilities of an SrB4O7 crystal and have determined its electromechanical coupling coefficients, piezoelectric charge and voltage constants, and bulk acoustic wave velocities by a resonance method using high-Q resonators. In addition, the dielectric permittivity of the crystal has been measured at 1 kHz. 相似文献
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Thin films of ZnIn2Se4 were deposited on quartz substrates at 297 K by the conventional thermal evaporation technique. The as-deposited films were amorphous. On annealing at 623 K under vacuum for 3 h, the films crystallized with a preferred (1 1 2) orientation corresponding to the chalcopyrite-type structure. Films deposited on a quartz substrate heated to 573 K were also crystalline. The optical constants were computed from the measured transmittance and reflectance at normal incidence of light in the wavelength range 400 to 2000 nm. The analysis of the data gave a direct gap of 2.2 and 2.06 eV for the amorphous and crystallized films, respectively. The dispersion curve exhibited a peak above the absorption edge. An indirect gap of 1.8 eV for the crystallized films and a direct forbidden gap of 1.75 eV for the amorphous films were also deduced. A direct allowed transition with a gap of 2.065 eV and an indirect transition with a gap of 1.69 eV were deduced for the crystalline films deposited on the heated substrate. 相似文献
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4-Nitrobenzoic acid (4-NBA) single crystals were studied for their linear and nonlinear optical properties. The crystals were grown by slow solvent evaporation method at room temperature. The structure and functional groups were confirmed by X-ray diffraction (XRD) and Fourier transform infrared (FTIR) spectroscopic studies. The 4-NBA crystal has an optical absorption at 263 nm and a wide transparency window for the visible light. Theoretical predictions for the measured optical absorption and charge transfer mechanism in 4-NBA were explained with HOMO and LUMO illustrations. The crystal is found to be birefringent and has produced an optical quality interference pattern. The optic plane of the crystal is observed along \(\langle 1 0 0\rangle \) direction. The crystal exhibits nonlinear optical effects viz. reverse saturable absorption and self-defocussing of laser beam. Considerable nonlinear refraction \((n_{2})\) and nonlinear absorption (\(\beta \)) coefficients and third-order nonlinear optical susceptibility \((\chi ^{(3)})\) were determined using Z-scan technique. 相似文献
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Synthesis and optical properties of TiO2 nanoparticles 总被引:1,自引:0,他引:1
Yin Zhao Xiuhong Liu Feng Gu Haibo Jiang Wei Shao Ling Zhang Ying He 《Materials Letters》2007,61(1):79-83
Ultrafine TiO2 particles have been synthesized successfully by a facile gas flame combustion method. The synthesized sample is characterized by X-ray diffraction (XRD), transmission electron micrograph (TEM), Fourier transform infrared (FTIR), and photoluminescence (PL) spectroscopy. The as-prepared TiO2 nanoparticles appear to be a single anatase crystalline phase and the diameter is about 9 nm. Besides a sharp emission at 398 nm originating from the radiative annihilation of excitions, a weak broad band at about 434 nm from the defect-related emission is also discussed. 相似文献