scholarly journals Identification of an Al–Ni–O precipitate in combustion-synthesized NiAl

2000 ◽  
Vol 33 (5) ◽  
pp. 1217-1222
Author(s):  
A. Biswas ◽  
Madangopal K. ◽  
J. B. Singh ◽  
S. K. Roy ◽  
S. Banerjee
Keyword(s):  
Room Temperature ◽  
Point Group ◽  
Composition Analysis ◽  
Second Phase ◽  
X Ray ◽  
Selected Area Electron Diffraction ◽  
Phase Precipitate ◽  
Transmission Electron ◽  
Chemical Composition Analysis

The complete identity of a second-phase precipitate detected by transmission electron microscopy in combustion-synthesized NiAl was established. The crystal structure, including the point group, the space group and the lattice parameters, was determined by convergent and selected-area electron diffraction techniques. Energy dispersive X-ray spectroscopy was used for the determination of the chemical composition. Analysis established the phase to be the solid solution of NiO in Al2O3and presented evidence of the hitherto unreported room-temperature solubility.

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.

A Chemical Solution Route to Rapid Synthesis of Homogeneous Bi100−xSbx Alloys Nanoparticles at Room Temperature

2007 ◽  
Vol 7 (2) ◽  
pp. 525-529 ◽  
Author(s):  
Bo Zhou ◽  
Jun-Jie Zhu
Keyword(s):  
Room Temperature ◽  
Raw Materials ◽  
X Ray Diffraction ◽  
X Ray ◽  
Selected Area Electron Diffraction ◽  
Transmission Electron ◽  
Solution Route ◽  
Diffraction Patterns ◽  
Co Reduction ◽  
Chemical Solution Route

A chemical co-reduction route in aqueous solution was developed to synthesize Bi100−xSbx alloys at room temperature. The hydrolyses of Bi(III) and Sb(III) were effectively avoided by selecting proper raw materials and coordinator. X-ray diffraction analysis indicated that the as-prepared Bi100−xSbx alloys were homogeneous and phase-pure, and the Bi/Sb ratios in the alloys were very close to those in the aqueous solutions. The transmission electron microscope observation showed that the as-prepared Bi100−xSbx (x = 0∼100) alloys were particles with a size of tens of nanometers. The selected area electron diffraction patterns confirmed the high crystallinity, the homogeneousness, and the composition controllability of as-prepared alloys. All these characters and the nanometer-scaled size of the alloys are believed to be beneficial to the thermoelectric property of the Bi100−xSbx alloys.

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.

Nanocrystalline and stacking-disordered β-cristobalite AlPO4 chemically stabilized at room temperature: synthesis, physical characterization, and X-ray powder diffraction data

2017 ◽  
Vol 32 (S1) ◽  
pp. S193-S200
Author(s):  
B. Peplinski ◽  
B. Adamczyk ◽  
P. Formanek ◽  
C. Meyer ◽  
O. Krüger ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Powder Diffraction ◽  
Title Compound ◽  
Room Temperature ◽  
Optical Emission ◽  
Xrd Pattern ◽  
X Ray ◽  
Selected Area Electron Diffraction ◽  
Transmission Electron

This paper reports the first successful synthesis and the structural characterization of nanocrystalline and stacking-disordered β-cristobalite AlPO4 that is chemically stabilized down to room temperature and free of crystalline impurity phases. Several batches of the title compound were synthesized and thoroughly characterized by X-ray powder diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy, selected area electron diffraction, energy dispersive X-ray spectroscopy mapping in SEM, solid-state 31P nuclear magnetic resonance (31P-NMR) spectroscopy including the TRAPDOR method, differential thermal analysis (DTA), gas-sorption methods, optical emission spectroscopy, X-ray fluorescence spectroscopy, and ion chromatography. Parameters that are critical for the synthesis were identified and optimized. The synthesis procedure yields reproducible results and is well documented. A high-quality XRD pattern of the title compound is presented, which was collected with monochromatic copper radiation at room temperature in a wide 2θ range of 5°–100°.

Unit cell determination of 2,3,9,10,16,17,23,24- octapentoxyphthalocyanine and its nickel derivative using electron and X-ray powder diffraction

2000 ◽  
Vol 04 (01) ◽  
pp. 10-18 ◽  
Author(s):  
S. STEINBRECHER ◽  
F. ZHOU ◽  
E. PLIES ◽  
M. HANACK
Keyword(s):  
Powder Diffraction ◽  
Hexagonal Phase ◽  
Columnar Structure ◽  
Unit Cell ◽  
Second Phase ◽  
X Ray ◽  
Metal Free ◽  
Energy Filtering ◽  
Transmission Electron

2,3,9,10,16,17,23,24-Octapentoxyphthalocyanine and its nickel derivative have been studied by means of electron and X-ray powder diffraction. The results reveal that the metal-free compound forms monoclinic crystals (space group C2/c) with unit cell constants a = 4.202 nm , b = 0.4977 nm , c = 3.345 nm , β = 98.9 ° and Z = 4 molecules per unit cell. 2,3,9,10,16,17,23,24-Octapentoxyphthalocyaninatonickel(II) is likely to be isomorphous to its metal-free analogue, but occurs in a second phase which is also stable at room temperature. This is identified to be a crystalline primitive hexagonal phase with cell constants a = b = 2.50 nm and c = 0.33 nm . It is assumed that the molecules form a columnar structure along the c-axis, whereas the hexagonal cross-section in the ab-plane goes back to the molecular disc shape. Imaging of monoclinic crystals of 2,3,9,10,16,17,23,24-octapentoxyphthalocyanine in an energy-filtering transmission electron microscope (EFTEM) can be performed to resolve 2 nm structures only, owing to specimen damage. According to the diffraction pattern, the micrograph provides a view along [001] and shows directly that the structure can be described in terms of parallel columnar stacks of molecules along the b-axis, the distance between neighbouring stacks being [Formula: see text]. The results show that the structures of both the metal-free compound and its nickel analogue are dominated by π–π interactions between the macrocycles, which is a marked difference from the structures of 1,4,8,11,15,18,22,25-octasubstituted phthalocyanines.

Large Scale Synthesis of Shuttle like CuO Nanocrystals by Microwave Irradiation

2010 ◽  
Vol 92 ◽  
pp. 117-123 ◽  
Author(s):  
Pei Jun Cai ◽  
Mei Shi
Keyword(s):  
Microwave Irradiation ◽  
Photoelectron Spectroscopy ◽  
Large Scale ◽  
Room Temperature ◽  
Monoclinic Phase ◽  
Aqueous System ◽  
X Ray ◽  
Selected Area Electron Diffraction ◽  
Transmission Electron ◽  
Cuo Nanocrystals

Nanocrystalline CuO with shuttle-morphology has been prepared conventionally by a microwave irradiation heating technique from an aqueous system in the presence of Cu(CH3COO)2• H2O and NaOH at room temperature. The X-ray powder diffraction pattern indicates that the product is indicated that the product was pure monoclinic phase of CuO. Further characterized by transmission electron microscopy, selected area electron diffraction, X-ray photoelectron spectroscopy and Raman spectra, the component of the products were confirmed.

Synthesis and electro-magnetic properties of flower-like Fe2O3-Ag nanocomposite using direct subsidence loading method

2015 ◽  
Vol 08 (01) ◽  
pp. 1550013 ◽  
Author(s):  
Xing Zhou ◽  
Zhengying Wu ◽  
Nan Xu ◽  
Shouqing Liu ◽  
Guizhe Zhao ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Room Temperature ◽  
Magnetic Measurement ◽  
X Ray ◽  
Selected Area Electron Diffraction ◽  
Loading Method ◽  
Transmission Electron ◽  
Electro Magnetic ◽  
Conductive Properties

Novel flower-like Fe 2 O 3/ Ag nanocomposites were synthesized by a simple direct subsidence loading method. The composition and morphology of the obtained samples were characterized by X-ray powder diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), high resolution transmission electron microscopy (HRTEM) and selected area electron diffraction (SEAD) techniques. The Ag nanoparticles which loaded on the surface of petals exhibit spherical morphology. Further, the magnetic and electrical conductive properties reveal the well controllable performance. Room temperature magnetic measurement of the flower-like nanocomposites demonstrated its ferromagnetic properties and the saturation magnetization (Ms) decreased from 0.6 to 0.11 emu/g.

Single Crystal InSb Nanowires: Synthesis, Characterization, Properties and Applications

2006 ◽  
Vol 940 ◽  
Author(s):  
Qi Laura Ye ◽  
Toshishige Yamada ◽  
Hongbing Liu ◽  
Raymond Scheffler ◽  
Natalio Mingo ◽  
...  
Keyword(s):  
Single Crystal ◽  
Large Scale ◽  
Growth Direction ◽  
Composition Analysis ◽  
X Ray ◽  
Selected Area Electron Diffraction ◽  
Transmission Electron ◽  
Bcc Structure ◽  
Lattice Planes ◽  
Insb Nanowires

ABSTRACTWe report the first large-scale synthesis of single crystal InSb nanowires using vapor-liquid-solid (VLS) transport process. Narrow growth window for achieving single crystal InSb nanowires has been discovered. Our batch produced InSb nanowires are 50-180 nm in diameter and 10-30 μ in length. Materials composition analysis by Energy-Dispersive X-ray Spectroscopy (EDAX) reveals that the as-grown InSb nanowires are pure single crystals of InSb. Structural analysis by High Resolution Transmission Electron Microscopy (HRTEM) and Selected Area Electron Diffraction (SAED) reveals that InSb nanowires have body-centered-cubic (BCC) crystal structure with cubic unit cell length of 10.15 Å. The nanowire growth direction is found to be [001], 45 degrees toward the most dense lattice planes in BCC structure.

scholarly journals CdS Nanotubes and Y-Branched Nanochannels in AAM Fabricated by a Double Diffusion Route

2011 ◽  
Vol 2011 ◽  
pp. 1-6 ◽  
Author(s):  
Yong Lv ◽  
Weifeng Liu ◽  
Jianming Huang ◽  
Lianzeng Yao
Keyword(s):  
Room Temperature ◽  
Double Diffusion ◽  
Diffusion Method ◽  
Anodic Alumina Membrane ◽  
Alumina Membrane ◽  
X Ray ◽  
Nanostructure Materials ◽  
Selected Area Electron Diffraction ◽  
Transmission Electron ◽  
Potential Applications

Polycrystalline CdS nanotubes and a novel partition nanostructure were prepared in an anodic alumina membrane (AAM) template using a double diffusion method at room temperature. Transmission electron microscopy (TEM), selected area electron diffraction (SAED) and energy dispersive X-ray spectroscopy (EDX) investigations indicate that the nanotubes consisting of CdS grains have been synthesized in the AAM nanoholes. The influence of the reagent concentration on the morphology of the nanotubes has been systemically studied using a field emission scanning electron microscope (FE-SEM). It is confirmed that the Y-branched nanochannels can only formed under certain concentrations of the reactants ( and solutions). This novel Y-branched nanostructure may have potential applications for preparation of complicated nanostructure materials.

Single Crystal Growth of High-Pressure Phases of Ice and Salt Hydrate Far Below the Original Melting Point by Mixing Alcohol: Crystal Structure Determination of Magnesium Chloride Heptahydrate

2020 ◽  
Author(s):  
Keishiro Yamashita ◽  
Kazuki Komatsu ◽  
Hiroyuki Kagi
Keyword(s):  
Crystal Structure ◽  
High Pressure ◽  
Crystal Growth ◽  
Single Crystal ◽  
Room Temperature ◽  
Growth Technique ◽  
Salt Hydrate ◽  
X Ray

An crystal-growth technique for single crystal x-ray structure analysis of high-pressure forms of hydrogen-bonded crystals is proposed. We used alcohol mixture (methanol: ethanol = 4:1 in volumetric ratio), which is a widely used pressure transmitting medium, inhibiting the nucleation and growth of unwanted crystals. In this paper, two kinds of single crystals which have not been obtained using a conventional experimental technique were obtained using this technique: ice VI at 1.99 GPa and MgCl<sub>2</sub>·7H<sub>2</sub>O at 2.50 GPa at room temperature. Here we first report the crystal structure of MgCl2·7H2O. This technique simultaneously meets the requirement of hydrostaticity for high-pressure experiments and has feasibility for further in-situ measurements.

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