Synthesis and Properties of GaN Nanostructures

2005 ◽  
Vol 475-479 ◽  
pp. 3367-3370
Author(s):  
Hong-Lei Ma ◽  
Cheng Shan Xue ◽  
Ying Ge Yang ◽  
Hui Zhao Zhang ◽  
Jin Ma ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Hexagonal Wurtzite Structure ◽  
X Ray Diffraction ◽  
High Quality ◽  
One Dimensional ◽  
X Ray ◽  
Gan Nanowires ◽  
Transmission Electron ◽  
Morphology And Structure ◽  
Scanning Electron

One-dimensional GaN nanostructure films were successfully synthesized by the recently developed sputtering post-nitridation technique. The morphology and structure of GaN nanowires are investigated by X-ray diffraction (XRD), transmission electron microscopy (TEM), and scanning electron microscopy (SEM). The results indicate that the crystalline GaN nanostructures have a hexagonal wurtzite structure, and there is not any other phase such as Ga2O3 or Ga in the specimen. It also confirms that high quality crystal was obtained in the resulting sample due to the lattice defects decreased and the crystallinity improved in the process of nitridation at high temperature. The growth mechanism of the GaN nanostructures is briefly discussed.

INFLUENCE OF AMMONIATING TIME ON Nb-CATALYZED GaN NANOSTRUCTURED MATERIALS

2011 ◽  
Vol 10 (06) ◽  
pp. 1209-1214 ◽  
Author(s):  
HUIZHAO ZHUANG ◽  
JIE WANG ◽  
XIAOKAI ZHANG ◽  
JUNLIN LI
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Nanostructured Materials ◽  
X Ray Diffraction ◽  
X Ray ◽  
Turn On ◽  
Transmission Electron ◽  
Morphology And Structure ◽  
Scanning Electron

Gallium nitride ( GaN ): nanostructured materials are synthesized by ammoniating Ga2O3/Nb films which are deposited in turn on Si(111) substrates at 900°C. The morphology and structure of the nanostructured materials are characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), and transmission electron microscopy (TEM). Optical property of GaN nanostructured materials are analyzed by photoluminescence (PL). The results demonstrated that as-synthesized nanostructured materials are hexagonal wurtzite-structured. Ammoniating time of the samples has an evident influence on the morphology of GaN nanostructured materials synthesized by this method. The PL spectra indicate good emission property for the nanostructured materials. Finally, the growth mechanism is also briefly discussed.

MICROWAVE HYDROTHERMAL SYNTHESIS OF RUTILE TiO2 NANORODS

2005 ◽  
Vol 19 (15n17) ◽  
pp. 2763-2768 ◽  
Author(s):  
GUOBIN MA ◽  
XIAONING ZHAO ◽  
JIANMIN ZHU
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
X Ray Diffraction ◽  
High Quality ◽  
X Ray ◽  
Microwave Hydrothermal ◽  
Transmission Electron ◽  
Microwave Hydrothermal Method ◽  
Scanning Electron

We present in this paper the synthesis of rutile TiO 2 nanorods using an efficient microwave hydrothermal method. The product was characterized by X-ray diffraction, scanning electron microscopy and transmission electron microscopy, and the results indicated the growth of high quality rutile nanorods along the c-axis of rutile TiO 2 and the radial aggregation of them into spherical secondary nanoparticles.

scholarly journals Growth of ZnO Nanowires in Aqueous Solution by a Dissolution-Growth Mechanism

2008 ◽  
Vol 2008 ◽  
pp. 1-5 ◽  
Author(s):  
Shaojing Bu ◽  
Chunxiang Cui ◽  
Qingzhou Wang ◽  
Ling Bai
Keyword(s):  
Electron Microscopy ◽  
Aqueous Solution ◽  
Growth Mechanism ◽  
Zno Nanowires ◽  
Film Morphology ◽  
X Ray Diffraction ◽  
X Ray ◽  
Transmission Electron ◽  
Morphology And Structure ◽  
Scanning Electron

A novel methodology based on the dissolution-growth mechanism was developed to prepare ZnO nanowires films. The film morphology and structure were investigated by using field emission scanning electron microscopy, high-resolution transmission electron microscopy and X-ray diffraction analysis methods. The results show that the ZnO nanowires are single crystallinec-oriented wurtzite. The ZnO rod crystals were eroded to provide the growth primitive of ZnO nanowires, which formed on top of the rod crystals when the erosion reaction got the equilibrium. The length of the resultant nanowires is rather large because the successive erosion of the rod crystals maintains the low concentration ofZn2O(OH)2n−2in the aqueous solution.

Influence of Ammoniating Temperatures on Microstructures, Morphologies and Optical Properties of GaN/Nb Nanostructures by RF Magnetron Sputtering Technique

2012 ◽  
Vol 1439 ◽  
pp. 17-23
Author(s):  
Feng Shi ◽  
Chengshan Xue
Keyword(s):  
Electron Microscopy ◽  
Optical Properties ◽  
Magnetron Sputtering ◽  
Photoelectron Spectroscopy ◽  
Hexagonal Wurtzite Structure ◽  
Rf Magnetron Sputtering ◽  
X Ray Diffraction ◽  
X Ray ◽  
Gan Nanowires ◽  
Transmission Electron

AbstractGaN nanowires and nanorods have been successfully synthesized on Si (111) substrates by magnetron sputtering through ammoniating Ga2O3/Nb thin films and the effects of ammoniation temperatures on growth of GaN nanowires and nanorods were analyzed in detail. X-ray diffraction, X-ray photoelectron spectroscopy, scanning electron microscopy, high-resolution transmission electron microscopy, and photoluminescence spectra were carried out to characterize microstructures, morphologies, and optical properties of GaN samples. The results demonstrate that sample after ammoniation at 950 °C is single crystal GaN with hexagonal wurtzite structure and high crystalline quality, having the size of 30 - 80 nm in diameter. After ammoniation at 1000 °C, GaN nanorods appear with smooth and clean surface and more than 100 nm in diameter. The optical properties of GaN nanowires grown at 950 °C and nanorods grown at 1000 °C are best with strong emission intensities.

scholarly journals Control of the Morphology of Molybdenum Dioxide Nanoparticles

2012 ◽  
Vol 9 (1) ◽  
pp. 233-239 ◽  
Author(s):  
R. Naouel ◽  
F. Touati ◽  
N. Gharbi
Keyword(s):  
Electron Microscopy ◽  
Thermal Analysis ◽  
Scanning Electron Microscopy ◽  
Hydrothermal Process ◽  
X Ray Diffraction ◽  
Molybdenum Dioxide ◽  
One Dimensional ◽  
X Ray ◽  
Transmission Electron ◽  
Scanning Electron

Synthesis of MoO2nanoparticles with one-dimensional (1D) and spherical morphologies in aqueous solutions, through hydrothermal process was investigated. The materials were studied by x-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), Infrared spectroscopy (FTIR) and thermal analysis (TG). It was found that the quantity of organic compound influenced the size and shape of the final product. The possible formation mechanism of MoO2microspheres and nanowires was also discussed. The conductivity of MoO2nanowires was explained by the presence of two protons types in the material.

scholarly journals SEM and TEM evidence of mixed-layer illite-smectite formed by dissolutioncrystallization processes in continental Paleogene sequences in northwestern Argentina

Clay Minerals ◽  
2016 ◽  
Vol 51 (5) ◽  
pp. 723-740 ◽  
Author(s):  
Margarita Do Campo ◽  
Blanca Bauluz ◽  
Fernando Nieto ◽  
Cecilia Del Papa ◽  
Fernando Hongn
Keyword(s):  
Electron Microscopy ◽  
Active Faults ◽  
X Ray Diffraction ◽  
High Quality ◽  
Northwestern Argentina ◽  
X Ray ◽  
Octahedral Sites ◽  
Al Substitution ◽  
Transmission Electron ◽  
Scanning Electron

AbstractIn the northernmost Calchaquí Valley (Salta, Argentina), the Paleogene continental sediments show a transition from smectite, at the top, to R3 I-S (>90% illite) through R1 I-S (65–80% illite), in contrast to the remaining sectors, containing smectite up to the bottom. Samples at the base of the succession were characterized by high-quality step-scan X-ray diffraction (XRD), scanning electron microscopy (SEM) and analytical high-resolution transmission electron microscopy (HRTEM). Analysis by SEM demonstrated dissolution of primary phases (feldspars, micas and quartz) and crystallization of illite, I-S and kaolinite. As this alteration is not pervasive, an intermediate fluid/rock ratio could be inferred. The lattice-fringe images of the samples from upper parts of the sequence show abundant I1-rich areas, whereas in the lower parts of the sequence, illite packets and I3 I-S coexist and compositions evolve towards muscovite (tetrahedral-charge increase, principally compensated by Mgby- Al substitution in octahedral sites and by a slight decrease in Ca in interlayer sites). As burial temperatures were probably similar in all the samples, depth was not responsible for the illite formation at the bottom. The TEM textures suggest that illitization proceeded mainly by dissolution-crystallization. The active faults close to the northern Calchaquí Valley probably promoted the circulation of hot, deep fluids, favouring illitization.

Identification of calcium oxalate crystals in dried or fixed tobacco leaf

1984 ◽  
Vol 42 ◽  
pp. 288-289
Author(s):  
Vicki L. Baliga ◽  
Mary Ellen Counts
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Calcium Oxalate ◽  
Growth And Development ◽  
Polarized Light ◽  
Calcium Oxalate Crystals ◽  
X Ray Diffraction ◽  
X Ray ◽  
Transmission Electron ◽  
Scanning Electron

Calcium is an important element in the growth and development of plants and one form of calcium is calcium oxalate. Calcium oxalate has been found in leaf seed, stem material plant tissue culture, fungi and lichen using one or more of the following methods—polarized light microscopy (PLM), scanning electron microscopy (SEM), transmission electron microscopy (TEM) and x-ray diffraction.Two methods are presented here for qualitatively estimating calcium oxalate in dried or fixed tobacco (Nicotiana) leaf from different stalk positions using PLM. SEM, coupled with energy dispersive x-ray spectrometry (EDS), and powder x-ray diffraction were used to verify that the crystals observed in the dried leaf with PLM were calcium oxalate.

The Effect of the Microstructure of Diffusion Barriers on the Palladium Activation for Electroless Copper Deposition

2002 ◽  
Vol 716 ◽  
Author(s):  
Seok Woo Hong ◽  
Yong Sun Lee ◽  
Ki-Chul Park ◽  
Jong-Wan Park
Keyword(s):  
Electron Microscopy ◽  
Diffusion Barriers ◽  
Copper Deposition ◽  
X Ray Diffraction ◽  
Plan View ◽  
X Ray ◽  
Transmission Electron ◽  
Electroless Copper ◽  
Sheet Resistance Measurement ◽  
Scanning Electron

AbstractThe effect of microstructure of dc magnetron sputtered TiN and TaN diffusion barriers on the palladium activation for autocatalytic electroless copper deposition has been investigated by using X-ray diffraction, sheet resistance measurement, field emission scanning electron microscopy (FE-SEM) and plan view transmission electron microscopy (TEM). The density of palladium nuclei on TaN diffusion barrier increases as the grain size of TaN films decreases, which was caused by increasing nitrogen content in TaN films. Plan view TEM results of TiN and TaN diffusiton barriers showed that palladium nuclei formed mainly on the grain boundaries of the diffusion barriers.

Hydrothermal Synthesis and Characterization of BiFeO3 Polyhedral Crystallites

2012 ◽  
Vol 174-177 ◽  
pp. 508-511
Author(s):  
Lin Lin Yang ◽  
Yong Gang Wang ◽  
Yu Jiang Wang ◽  
Xiao Feng Wang
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Synthesis And Characterization ◽  
X Ray Diffraction ◽  
Xrd Pattern ◽  
X Ray ◽  
Transmission Electron ◽  
Scanning Electron

BiFeO3 polyhedrons had been successfully synthesized via a hydrothermal method. The as-prepared products were characterized by power X-ray diffraction (XRD) pattern, scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The possible mechanisms for the formation of BiFeO3 polyhedrons were discussed. Though comparison experiments, it was found that the kind of precursor played a key role on the morphology control of BiFeO3 crystals.

Synthesis and Study the Properties of a Solar Cell of Gold Nanoparticles Prepared in a Simple Chemical Way

2021 ◽  
Vol 19 (11) ◽  
pp. 66-71
Author(s):  
Maithm A. Obaid ◽  
Suha A Fadaam ◽  
Osama S. Hashim
Keyword(s):  
Electron Microscopy ◽  
Gold Nanoparticles ◽  
Chemical Method ◽  
X Ray Diffraction ◽  
Structural And Optical Properties ◽  
Casting Method ◽  
X Ray ◽  
Transmission Electron ◽  
Simple Chemical ◽  
Scanning Electron

The aim of this study is to prepare gold nanoparticles by a simple chemical method at a temperature of 70°C. The solution was dried on glass basest by Casting method, the rate of five drops per sample At a temperature 100 C. Then the structural and optical properties have been confirmed by X-ray diffraction, scanning electron microscopy (SEM) and Transmission Electron microscope (TEM), Fourier Transform Infrared Spectroscopy (FTIR) and spectrum.

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