scholarly journals Oxalic Acid-Assisted Hydrothermal Synthesis and Luminescent of Hexagonal NaYF4:Ln3+ (Ln = Sm, Eu, Yb/Er) Micro/Nanoplates

2017 ◽  
Vol 2017 ◽  
pp. 1-10 ◽  
Author(s):  
Feng Tao ◽  
Zhishun Shen ◽  
Zhijun Wang ◽  
Da Shu ◽  
Qi Liu ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Oxalic Acid ◽  
Molar Ratio ◽  
Photoluminescence Properties ◽  
X Ray Diffraction ◽  
X Ray ◽  
Ph Values ◽  
Selected Area Electron Diffraction ◽  
Transmission Electron ◽  
Display Systems

Hexagonal NaYF4:Ln3+ micro/nanoplates were successfully synthesized via a hydrothermal method using oxalic acid as a shape modifier. X-ray diffraction (XRD), field emission scanning electron microscopy (FE-SEM), transmission electron microscopy (TEM), and selected area electron diffraction (SAED) have been used to study the morphologies and crystal structure of the products. The effects of the pH values and the molar ratio of oxalic acid to NaOH on the crystal growth have been investigated in detail. The time-dependent experiments have been conducted to investigate the morphology evolution process, and based on the results, a possible growth mechanism was proposed. The photoluminescence properties of 5 mol% Eu3+ and 3 mol% Sm3+ doped NaYF4 and 20 mol% Yb3+/2 mol% Er3+ codoped NaYF4 micro/nanoplates were investigated. The experimental results showed that NaYF4:Ln3+ micro/nanoplates have excellent luminescence and can be potential application in the field of light display systems, lasers, and optoelectronic devices.

Synthesis and Photoluminescence Properties of Novel SnO2 Zigzag Nanoribbons

2010 ◽  
Vol 97-101 ◽  
pp. 4213-4216
Author(s):  
Jian Xiong Liu ◽  
Zheng Yu Wu ◽  
Guo Wen Meng ◽  
Zhao Lin Zhan
Keyword(s):  
Electron Microscopy ◽  
Room Temperature ◽  
Vapour Deposition ◽  
Chemical Vapour ◽  
Photoluminescence Properties ◽  
X Ray Diffraction ◽  
X Ray ◽  
Selected Area Electron Diffraction ◽  
Transmission Electron ◽  
Ceramic Boat

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.

On the destruction of kaolinite and gibbsite by phenylphosphonic, phenylphosphinic and phenylarsonic acids: evidence for the formation of new Al compounds

Clay Minerals ◽  
2004 ◽  
Vol 39 (4) ◽  
pp. 391-404 ◽  
Author(s):  
J. E. F. C. Gardolinski ◽  
G. Lagaly ◽  
M. Czank
Keyword(s):  
Electron Microscopy ◽  
Thermal Analysis ◽  
Transmission Electron Microscopy ◽  
Fourier Transform ◽  
Linear Chain ◽  
X Ray Diffraction ◽  
Phenylphosphonic Acid ◽  
X Ray ◽  
Selected Area Electron Diffraction ◽  
Transmission Electron

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.

Preparation and Characterization of Helical Structure ZnS by Solvothermal Method

2011 ◽  
Vol 233-235 ◽  
pp. 1954-1957
Author(s):  
Xiao Yan Yan ◽  
Zhi Qiang Wei ◽  
Li Gang Liu ◽  
Xiao Juan Wu ◽  
Ge Zhang
Keyword(s):  
Electron Microscopy ◽  
Solvothermal Method ◽  
Helical Structure ◽  
Sodium Sulphide ◽  
X Ray Diffraction ◽  
Hexagonal Crystal ◽  
X Ray ◽  
Selected Area Electron Diffraction ◽  
Transmission Electron

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.

FABRICATION AND CHARACTERISTICS OF ALN NANOWIRES

2001 ◽  
Vol 15 (30) ◽  
pp. 1455-1458 ◽  
Author(s):  
H. CHEN ◽  
X. K. LU ◽  
S. Q. ZHOU ◽  
X. H. HAO ◽  
Z. X. WANG
Keyword(s):  
Crystal Structure ◽  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Single Phase ◽  
X Ray Diffraction ◽  
X Ray ◽  
Selected Area Electron Diffraction ◽  
Transmission Electron ◽  
Sublimation Method ◽  
Scanning Electron

Single phase AlN nanowires are fabricated by a sublimation method. They were characterized by means of X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), typical selected area electron diffraction (SAED) and high-resolution transmission electron microscopy (HRTEM). The SEM and TEM images show that most of the nanowires have diameters of about 10–60 nm. The crystal structure of AlN nanowires revealed by XRD, SAED and HRTEM shows the AlN nanowires have a wurtzite structure.

Non-crystalline hydrous feldspathoids in Late Permian carbonate rock

Clay Minerals ◽  
1991 ◽  
Vol 26 (4) ◽  
pp. 527-534 ◽  
Author(s):  
C. Bender Koch
Keyword(s):  
Electron Microscopy ◽  
Carbonate Rock ◽  
Crystalline Material ◽  
Molar Ratio ◽  
Late Permian ◽  
X Ray Diffraction ◽  
X Ray ◽  
Selective Area ◽  
Transmission Electron ◽  
Oolitic Shoal

AbstractThe EDTA-insoluble residues from five samples (two from the oolitic shoal facies and three from the lagoonal facies) of the Late Permian Ca-2 unit (Zechstein) have been investigated by X-ray diffraction, infrared spectroscopy, and scanning and transmission electron microscopy with energy dispersive X-ray analysis (EDXA). The results show that spheres of non-crystalline hydrous feldspathoids (with Al/Si molar ratio between 1·5 and 2·2) dominate the residues of samples from the oolitic shoal facies. Samples from the lagoonal facies are dominated by crystalline material (muscovite and quartz), but two of the samples contain a small number of spheres. Analyses of these samples by selective area diffraction and EDXA revealed the presence of small amounts of non-crystalline hydrous feldspathoids with Al/Si molar ratio between 0·1 and 1·9.

scholarly journals Solvent-Mediated Eco-Friendly Synthesis and Characterization of Monodispersed Bimetallic Ag/Pd Nanocomposites for Sensing and Raman Scattering Applications

2014 ◽  
Vol 2014 ◽  
pp. 1-9 ◽  
Author(s):  
G. Sathiyadevi ◽  
B. Loganathan ◽  
B. Karthikeyan
Keyword(s):  
Electron Microscopy ◽  
High Resolution ◽  
Dimethyl Formamide ◽  
X Ray Diffraction ◽  
X Ray ◽  
Selected Area Electron Diffraction ◽  
Transmission Electron ◽  
Bimetallic Nanocomposites ◽  
Ft Ir

The solvent-mediated eco-friendly monodispersed Ag/Pd bimetallic nanocomposites (BNCs) having thick core and thin shell have been prepared through novel green chemical solvent reduction method. Reducing solvent, dimethyl formamide (DMF) is employed for the controlled green synthesis. Characterization of the synthesized Ag/Pd BNCs has been done by x-ray diffraction (XRD) studies, high-resolution scanning electron microscopy (HR-SEM), energy-dispersive X-ray analysis (EDX), and high-resolution transmission electron microscopy (HR-TEM) with selected area electron diffraction (SAED) pattern. The nature of the interaction of L-cysteine with Ag/Pd BNCs has been studied by using surface plasmon spectroscopy, Fourier transform-infrared spectroscopy (FT-IR), cyclic voltammetry (CV), and theoretical methods.

PHOTOLUMINESCENCE SPECTRA AND MAGNETIC PROPERTIES OF HYDROTHERMALLY SYNTHESIZED MnO2 NANORODS

2013 ◽  
Vol 27 (29) ◽  
pp. 1350211 ◽  
Author(s):  
ARBAB MOHAMMAD TOUFIQ ◽  
FENGPING WANG ◽  
QURAT-UL-AIN JAVED ◽  
QUANSHUI LI ◽  
YAN LI
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Room Temperature ◽  
Blue Emission ◽  
Green Emission ◽  
X Ray Diffraction ◽  
X Ray ◽  
Selected Area Electron Diffraction ◽  
Uv Emission ◽  
Transmission Electron

In this paper, single crystalline tetragonal MnO 2 nanorods have been synthesized by a simple hydrothermal method using MnSO 4⋅ H 2 O and Na 2 S 2 O 8 as precursors. The crystalline phase, morphology, particle sizes and component of the as-prepared nanomaterial were characterized by employing X-ray diffraction (XRD), field-emission scanning electron microscopy (FESEM), transmission electron microscopy (TEM), high-resolution transmission electron microscopy (HRTEM), selected area electron diffraction (SAED) and energy-dispersive X-ray spectroscopy (EDS). The photoluminescence (PL) emission spectrum of MnO 2 nanorods at room temperature exhibited a strong ultraviolet (UV) emission band at 380 nm, a prominent blue emission peak at 453 nm as well as a weak defect related green emission at 553 nm. Magnetization (M) as a function of applied magnetic field (H) curve showed that MnO 2 nanowires exhibited a superparamagnetic behavior at room temperature which shows the promise of synthesized MnO 2 nanorods for applications in ferrofluids and the contrast agents for magnetic resonance imaging. The magnetization versus temperature curve of the as-obtained MnO 2 nanorods shows that the Néel transition temperature is 94 K.

EFFECT OF pH ON ZnS NANOCRYSTALLINE THIN FILM EMBEDDED IN A POLYVINYL ALCOHOL MATRIX

2010 ◽  
Vol 24 (29) ◽  
pp. 5663-5673 ◽  
Author(s):  
J. P. BORAH ◽  
J. BARMAN ◽  
K. C. SARMA
Keyword(s):  
Electron Microscopy ◽  
Polyvinyl Alcohol ◽  
Ph Value ◽  
X Ray Diffraction ◽  
X Ray ◽  
Ph Values ◽  
Nanocrystalline Thin Film ◽  
Transmission Electron ◽  
Uv Visible ◽  
Compositional Characterization

Polyvinyl alcohol (PVA) has been used as a matrix to synthesize ZnS / PVA nanocomposite film on glass substrate by chemical method. Transmission electron microscopy (TEM), X-ray diffraction (XRD), Scanning electron microscopy (SEM) has been used for structural, morphological and compositional characterization. Optical properties have been studied by UV-Visible spectrophotometry and photoluminescence (PL) spectroscopy. Changing pH value from 4.8 to 0.8 decreases the particle size and correspondingly increases the band gap. The PL emission intensity also increases by decreasing the pH values.

Characteristics of SnO2 One-Dimensional Nanomaterials Synthesized on TiN-Coated Substrates by the Evaporation of Sn Powders

2006 ◽  
Vol 510-511 ◽  
pp. 658-661
Author(s):  
Hyoun Woo Kim ◽  
S.H. Shim ◽  
Ju Hyun Myung
Keyword(s):  
Electron Microscopy ◽  
Tin Oxide ◽  
Visible Region ◽  
Optoelectronic Devices ◽  
X Ray Diffraction ◽  
Rutile Structure ◽  
One Dimensional ◽  
X Ray ◽  
Selected Area Electron Diffraction ◽  
Transmission Electron

One-dimensional structures of tin oxide (SnO2) on TiN-coated substrates were obtained by simple heating of Sn powders. X-ray diffraction, high-resolution transmission electron microscopy, and the selected area electron diffraction showed that 1D structures are composed of SnO2 with rutile structure. The photoluminescence of the structures in the visible region suggests possible applications in nanoscaled optoelectronic devices.

Convenient Route to Cu-Ag Bimetallic Nanoleaflets with High Content of Cu and their Electrochemical Properties

2017 ◽  
Vol 727 ◽  
pp. 395-402
Author(s):  
Zi Run Wang ◽  
Xin Liu ◽  
Gui Qi Xie ◽  
Yi Wu ◽  
Ming Nie ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Reduction Method ◽  
Molar Ratio ◽  
X Ray Diffraction ◽  
X Ray ◽  
Molar Ratios ◽  
Phase Reduction ◽  
Transmission Electron ◽  
Convenient Route

Cu-Ag alloy nanoparticles were synthesized by a liquid phase reduction method. Using sodium formaldehyde sulfoxylate (SFS) as reducing agents, copper-silver bimetallic nanoleaflets with high content of Cu were prepared. The obtained Cu-Ag bimetallic nanocrystal were characterized by powder X-ray diffraction (XRD), energy dispersive X-ray spectroscopy (EDX), field emission scanning electron microscope (FESEM), high resolution transmission electron microscopy (HRTEM) and transmission electron microscopy (TEM). Different molar ratio of Cu-Ag bimetallic nanomaterials could produce different morphologies. The surfactant β-CD plays a crucial role on the structure of the products. The different molar ratios of Cu-Ag were also investigated. The electrochemical activity was evaluated using cyclic voltammetry (CV), electrochemical hydrogen evolution reaction (HER) in a 0.5M Na2SO4 electrolyte.

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