Optimized structural and optical behavior of Dy3+ ions doped SrS nano-powders for thin film fabrication

2019 ◽  
Vol 12 (05) ◽  
pp. 1950072
Author(s):  
Shubhra Mishra ◽  
D. S. Kshatri

Undoped and Dy[Formula: see text]-doped SrS nano-powders were synthesized by a solid-state diffusion method (SSDM). The nano-powders are then examined by the use of characterization tools as X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM) and high resolution transmission electron microscopy (HRTEM) including selected area electron diffraction (SAED). The emission spectra of SrS: Dy[Formula: see text] powders are composed of a broadband and the characteristic emission of Dy[Formula: see text] peaking at 482[Formula: see text]nm (blue region), 581[Formula: see text]nm (yellow region), 676[Formula: see text]nm (light red region) and 750[Formula: see text]nm (dark red region) bands corresponding to the transitions of 4F[Formula: see text]-6H[Formula: see text], 4F[Formula: see text]-6H[Formula: see text], 4F[Formula: see text]-6H[Formula: see text] and 4F[Formula: see text]-6H[Formula: see text], respectively. The resultant nano-powders can be used to fabricate thin films for the applications of efficient optoelectronic devices.

2010 ◽  
Vol 97-101 ◽  
pp. 4213-4216
Author(s):  
Jian Xiong Liu ◽  
Zheng Yu Wu ◽  
Guo Wen Meng ◽  
Zhao Lin Zhan

Novel single-crystalline SnO2 zigzag nanoribbons have been successfully synthesized by chemical vapour deposition. Sn powder in a ceramic boat covered with Si plates was heated at 1100°C in a flowing argon atmosphere to get deposits on a Si wafers. The main part of deposits is SnO2 zigzag nanoribbons. They were characterized by means of X-ray diffraction (XRD), field-emission scanning electron microscopy (FE-SEM), energy-dispersive X-ray spectroscopy (EDX), transmission electron microscopy (TEM) and selected-area electron diffraction (SAED). SEM observations reveal that the SnO2 zigzag nanoribbons are almost uniform, with lengths near to several hundred micrometers and have a good periodically tuned microstructure as the same zigzag angle and growth directions. Possible growth mechanism of these zigzag nanoribbons was discussed. A room temperature PL spectrum of the zigzag nanoribbons shows three peaks at 373nm, 421nm and 477nm.The novel zigzag microstructures will provide a new candidate for potential application.


2010 ◽  
Vol 8 (5) ◽  
pp. 1027-1033 ◽  
Author(s):  
Junhao Zhang ◽  
Yuhui Wu ◽  
Jia Zhu ◽  
Shaoxing Huang ◽  
Dongjing Zhang ◽  
...  

AbstractSelf-assembled CdS architectures with flower-like structures have been synthesized by a mixed solvothermal method using ethylene glycol and oleic acid as the mixed solvent at 160°C for 12 h. The results of X-ray diffraction (XRD) patterns, field-emission scanning electron microscopy (FESEM) and transmission electron microscopy (TEM) images indicate that the product exists as the hexagonal wurtzite phase and conatins of larger numbers of flower-like CdS architectures with diameters of 1.8–3 μm. The selected-area electron diffraction (SAED) pattern and the high resolution transmission electron microscope (HRTEM) image reveal that the grain has better crystallinity. The optical properties of flower-like CdS architectures were also investigated by ultraviolet-visable (UV-vis) and photoluminescence spectroscopy at room temperature. A strong peak at 490 nm is shown in the UV-vis absorption, while an emission at 486 nm and another strong emission at 712 nm are shown in the PL spectrum.


2014 ◽  
Vol 2014 ◽  
pp. 1-8 ◽  
Author(s):  
Younes Hanifehpour ◽  
Sang Woo Joo

Yb-doped Sb2Te3nanomaterials were synthesized by a coreduction method in hydrothermal condition. Powder X-ray diffraction patterns indicate that theYbxSb2−xTe3crystals (x=0.00–0.05) are isostructural with Sb2Te3. The cell parameteradecreases forYbxSb2−xTe3compounds upon increasing the dopant content (x), whilecincreases. Scanning electron microscopy and transmission electron microscopy images show that doping of Yb3+ions in the lattice of Sb2Te3produces different morphology. The electrical conductivity of Yb-doped Sb2Te3is higher than the pure Sb2Te3and increases with temperature. By increasing concentration of the Yb3+ions, the absorption spectrum of Sb2Te3shows red shifts and some intensity changes. In addition to the characteristic red emission peaks of Sb2Te3, emission spectra of doped materials show other emission bands originating fromf-ftransitions of the Yb3+ions. The photocatalytic performance of as-synthesized nanoparticles was investigated towards the decolorization of Malachite Green solution under visible light irradiation.


Clay Minerals ◽  
2004 ◽  
Vol 39 (4) ◽  
pp. 391-404 ◽  
Author(s):  
J. E. F. C. Gardolinski ◽  
G. Lagaly ◽  
M. Czank

AbstractKaolinite and synthetic γ-Al(OH)3 (gibbsite or hydrargillite) were reacted with phenylphosphonic, phenylphosphinic and 2-nitrophenol-4-arsonic acids. The products were studied by powder X-ray diffraction, transmission electron microscopy/selected area electron diffraction/ energy dispersive X-ray/Fourier transform infrared and simultaneous thermogravimetric/differential thermal analysis. The acids were not intercalated but, instead, easily destroyed the structure of the minerals. Lamellar Al phenylphosphonate and aluminium phenylphosphinate and phenylarsonate with polymeric linear-chain structures were formed from kaolinite. The reaction between gibbsite and the same acids yielded almost identical products. No evidence of formation of grafted kaolinite derivatives after the reaction with phenylphosphonic acid was found.


2010 ◽  
Vol 25 (10) ◽  
pp. 2035-2041 ◽  
Author(s):  
Zhiguo Xia ◽  
Peng Du

CaF2:Yb3+,Er3+ upconversion (UC) luminescence nanoparticles have been synthesized using mesoporous silica (SBA-15) as a hard template. The samples were characterized by x-ray diffraction, Fourier transform infrared spectra, field-emission scanning electron microscopy, transmission electron microscopy, and UC emission spectra, respectively. Highly crystalline cubic phase CaF2:Yb3+,Er3+ nanoparticles are uniformly distributed with an average diameter of about 40–50 nm, and the formation process is also demonstrated. The UC fluorescence has been realized in the as-prepared CaF2:Yb3+,Er3+ nanoparticles on 980-nm excitation. The UC emission transitions for 4F9/2–4I15/2 (red), 2H11/2–4I15/2 (green), 4S3/2–4I15/2 (green), and 2H9/2–4I15/2 (violet) in the Yb3+/Er3+ codoped CaF2 nanoparticles depending on pumping power and temperature have been discussed. The UC mechanism, especially the origin on the temperature-dependent UC emission intensities ratio between 2H11/2 and 4S3/2 levels, have been proposed.


2015 ◽  
Vol 2015 ◽  
pp. 1-7 ◽  
Author(s):  
C. Massard ◽  
S. Pairis ◽  
V. Raspal ◽  
Y. Sibaud ◽  
K. O. Awitor

The feasibility of surface nanopatterning with TiO2nanotanks embedded in a nanoporous alumina template was investigated. Self-assembled anodized aluminium oxide (AAO) template, in conjunction with sol gel process, was used to fabricate this nanocomposite object. Through hydrolysis and condensation of the titanium alkoxide, an inorganic TiO2gel was moulded within the nanopore cavities of the alumina template. The nanocomposite object underwent two thermal treatments to stabilize and crystallize the TiO2. The morphology of the nanocomposite object was characterized by Field Emission Scanning Electron Microscopy (FESEM). The TiO2nanotanks obtained have cylindrical shapes and are approximately 69 nm in diameter with a tank-to-tank distance of 26 nm. X-ray diffraction analyses performed by Transmission Electron Microscopy (TEM) with selected area electron diffraction (SAED) were used to investigate the TiO2structure. The optical properties were studied using UV-Vis spectroscopy.


NANO ◽  
2016 ◽  
Vol 11 (03) ◽  
pp. 1650034
Author(s):  
Xinliang Zheng ◽  
Juan Feng ◽  
Jiarui Zhang ◽  
Hongna Xing ◽  
Jiming Zheng ◽  
...  

High-quality neodymium oxychlorides nanocrystals with cubic shape were synthesized by a nonhydrolytic thermolysis route. The morphology and crystal structure of the neodymium oxychlorides nanocubes were characterized by transmission electron microscopy at the nanoscale. Transmission electron microscope (TEM) image shows that the neodymium oxychlorides nanocrystals are nearly monodispersed with cube-like shape. X-ray diffraction (XRD) and selected area electron diffraction (SAED) patterns of numerous neodymium oxychlorides nanocubes suggest a pure crystal phase with tetragonal PbFCl matlockite structure. HRTEM image of individual neodymium oxychlorides nanocubes indicate that each nanocubes have a single-crystalline nature with high quality. Unlike the anti-ferromagnetism of the bulk, the neodymium oxychlorides nanocubes show clearly anomalous ferromagnetic characteristic at room temperature. This finding provides a new platform for the exploration of diluted magnetic semiconductors, rare earth-based nanomaterials and so on.


2015 ◽  
Vol 821-823 ◽  
pp. 213-216
Author(s):  
S.M. Ryndya ◽  
N.I. Kargin ◽  
A.S. Gusev ◽  
E.P. Pavlova

Silicon carbide thin films were obtained on Si (100) and (111) substrates by means of vacuum laser ablation of α-SiC ceramic target. The influence of substrate temperature on composition, structure and surface morphology of experimental samples was examined using Rutherford backscattering spectrometry (RBS), Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), conventional and high-resolution transmission electron microscopy (TEM/HRTEM), atomic force microscopy (AFM), selected area electron diffraction (SAED) and X-ray diffraction (XRD) methods.


2011 ◽  
Vol 2011 ◽  
pp. 1-5 ◽  
Author(s):  
Wenqing Qin ◽  
Congren Yang ◽  
Ran Yi ◽  
Guanhua Gao

Single-crystalline - nanocubes were successfully obtained in large quantities through a facile one-step hydrothermal synthetic route under mild conditions. In this synthetic system, aqueous iron (III) nitrate () served as iron source and triethylamine served as precipitant and alkaline agent. By prolonging reaction time from 1 h to 24 h, the evolution process of -, from nanorhombohedra to nanohexahedron, and finally nanocube, was observed. The products were characterized by Powder X-ray Diffraction (XRD), Scanning Electron Microscopy (SEM), Transmission Electron Microscopy (TEM), High-resolution Transmission Electron Microscopy (HRTEM), Selected-Area Electron Diffraction (SAED), and Fourier Transform Infrared Spectrometry (FTIR). The possible formation mechanism was discussed on basis of the experimental results.


2011 ◽  
Vol 233-235 ◽  
pp. 1954-1957
Author(s):  
Xiao Yan Yan ◽  
Zhi Qiang Wei ◽  
Li Gang Liu ◽  
Xiao Juan Wu ◽  
Ge Zhang

Helical structure ZnS were successfully prepared via solvothermal method by the reaction of zinc acetate and sodium sulphide. The composition, morphology, and microstructure of the sample were characterized by X-ray diffraction (XRD), high resolution transmission electron microscopy (HRTEM), the corresponding selected area electron diffraction (SAED) and X-ray energy spectrum (EDS). The experiment results show that the sample is 1-D hexagonal crystal ZnS and grows along the [002] direction, and is helical structure, with lengths in the range of 100-200 nm, the diameter about 5-15 nm, and pitch about 20nm.


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