scholarly journals Zn Electrodeposition on Single-Crystal GaN(0001) Surface: Nucleation and Growth Mechanism

2016 ◽  
Vol 2016 ◽  
pp. 1-8 ◽  
Author(s):  
Fei Peng ◽  
Shuang-Jiao Qin ◽  
Yu Zhao ◽  
Ge-Bo Pan
Keyword(s):  
Single Crystal ◽  
Electrochemical Techniques ◽  
Deposition Process ◽  
Nucleation And Growth ◽  
X Ray Diffraction ◽  
X Ray ◽  
Surface Nucleation ◽  
Instantaneous Nucleation ◽  
Nucleation And Growth Mechanism ◽  
Transient Measurements

The electrochemical deposition of zinc on single-crystaln-type GaN(0001) from a sulphate solution has been investigated on the basis of electrochemical techniques including cyclic voltammetry, chronoamperometry, and Tafel plot. The morphology and crystal structure of zinc deposits have been characterized by means of scanning electron microscopy, X-ray diffraction, and energy-dispersive X-ray analysis. The result has revealed that the deposition of Zn on GaN electrode commenced at a potential of −1.12 V versus Ag/AgCl. According to the Tafel plot, an exchange current density of ~0.132 mA cm−2was calculated. In addition, the current transient measurements have shown that Zn deposition process followed the instantaneous nucleation in 10 mM ZnSO4+ 0.5 M Na2SO4+ 0.5 M H3BO3(pH = 4).

Study on Preparation Process of ITO Nano-Powder by the Method of Ammonia Complexation

2012 ◽  
Vol 549 ◽  
pp. 441-444
Author(s):  
Li Da Sun ◽  
Du Shu Huang ◽  
Wei Liu ◽  
Yan Jiang ◽  
Rui Min Xiao ◽  
...  
Keyword(s):  
Photoelectron Spectroscopy ◽  
Nucleation And Growth ◽  
X Ray Diffraction ◽  
Spectroscopy Analysis ◽  
X Ray ◽  
Nano Powder ◽  
Transmission Electron ◽  
Tin Oxides ◽  
Size And Morphology ◽  
Nucleation And Growth Mechanism

ITO (Indium Tin Oxides) nano-powder was prepared by the method of ammonia complexation. The chemical composition, morphology and crystal structure were characterized by X-ray diffraction (XRD) ,transmission electron microscopy (TEM) and X-ray photoelectron spectroscopy analysis(XPS). Base on the nucleation and growth mechanism of the powder, the temperature of heat treatment impacting on size and morphology was discussed briefly. The results showed that the nano-ITO powder of particle size 20nm-40nm with well-pleasing particle shape and dispersion can be prepared at 800°C.

Effect of single crystal substrates on the growth and properties of superconducting Tl2Ba2CaCu2O8 films

1993 ◽  
Vol 8 (5) ◽  
pp. 962-972 ◽  
Author(s):  
W.L. Holstein ◽  
L.A. Parisi ◽  
R.B. Flippen ◽  
D.G. Swartzfager
Keyword(s):  
Single Crystal ◽  
Depth Profiling ◽  
Nucleation And Growth ◽  
Phase Changes ◽  
Ac Magnetic Susceptibility ◽  
Secondary Phases ◽  
X Ray Diffraction ◽  
X Ray ◽  
Oriented Films ◽  
Film Substrate

Superconducting Tl2Ba2CaCu2O8 films were prepared by a two-step postdeposition anneal process under identical conditions on a number of single crystal substrates: (100) LaAlO3, (100) NdGaO3, (100) LaGaO3, (100) SrTiO3, (100) MgO, and (0001) Al2O3. The properties of the resulting Tl2Ba2CaCu2O8 films were strongly dependent on the substrate. Films on all substrates were predominantly c-axis oriented. Films prepared on LaAlO3, NdGaO3, and LaGaO3 also exhibited in-plane epitaxy, while films on MgO, Al2O3, and SrTiO3 were not aligned with the substrates. Some a-axis oriented grains of Tl2Ba2CaCu2O8 formed on NdGaO3 and both a-axis oriented grains and cracks were present on LaGaO3. Large amounts of secondary phases, as indicated by additional peaks in the x-ray diffraction scans, were observed for films on Al2O3 and SrTiO3 and smaller amounts on each of the other substrates. Depth profiling by sputtered neutral mass spectroscopy (SNMS) confirmed the presence of strong film-substrate reactions on Al2O3 and SrTiO3, and also indicated the presence of a reaction on NdGaO3. The Tc onset of the films as measured both inductively and by ac magnetic susceptibility varied depending on the substrate. The highest quality films were prepared on LaAlO3. NdGaO3 may also prove to be an acceptable substrate if the nucleation and growth of a-axis oriented Tl2Ba2CaCu2O8 grains can be eliminated. The remaining substrates appear to be less suitable due to severe film-substrate interactions, lack of epitaxial growth, or crystallographic phase changes.

Preparation of ITO Nano-Powder by the Method of Ammonia Complexation and Calcination

2014 ◽  
Vol 968 ◽  
pp. 76-79 ◽  
Author(s):  
Li Da Sun ◽  
Yan Jiang ◽  
Zi Jing Li ◽  
Rui Min Xiao ◽  
Shun Li Lu
Keyword(s):  
Crystal Structure ◽  
Electron Microscopy ◽  
Nucleation And Growth ◽  
X Ray Diffraction ◽  
X Ray ◽  
Nano Powder ◽  
Transmission Electron ◽  
Tin Oxides ◽  
Size And Morphology ◽  
Nucleation And Growth Mechanism

ITO (Indium Tin Oxides) nanopowder was prepared by ammonium-calcining method. The chemical composition, morphology and crystal structure were characterized by X-ray diffraction (XRD) and transmission electron microscopy (TEM). Base on the nucleation and growth mechanism of the powder, the temperature of heat treatment impacting on size and morphology was discussed briefly. The results showed that the nanoITO powder of particle size 20nm-40nm with well-pleasing particle shape and dispersion can be prepared at 800°C.

Nucleation and growth of silicon nitride nanoneedles using microwave plasma heating

2001 ◽  
Vol 16 (11) ◽  
pp. 3111-3115 ◽  
Author(s):  
H. Cui ◽  
B. R. Stoner
Keyword(s):  
Electron Microscope ◽  
Silicon Nitride ◽  
Microwave Plasma ◽  
Plasma Heating ◽  
Catalyst Particle ◽  
Nucleation And Growth ◽  
X Ray Diffraction ◽  
X Ray ◽  
Transmission Electron ◽  
Nucleation And Growth Mechanism

We report on needlelike silicon nitride nanowires grown on silicon using ammonia microwave plasma heating. Scanning electron microscope reveals that the nanoneedles are either straight, slightly bent, or kinked with sharp tips. Transmission electron microscope shows that the sizes of the nanowire tips are less than 5 nm and the structures are well crystallized. X-ray diffraction on the surface of the as-deposited structures indicates that both α-silicon nitride and β-silicon nitride exist. Catalyst particle splitting and merging explain observed structure derivation and bending. A vapor–liquid–solid model is employed to explain nucleation and growth mechanism.

Preparation of ITO Nano-Powder by the Method of Ammonia Complexation

2011 ◽  
Vol 393-395 ◽  
pp. 254-257
Author(s):  
Li Da Sun ◽  
Du Shu Huang ◽  
Wei Liu ◽  
Yan Jiang ◽  
Rui Min Xiao
Keyword(s):  
Crystal Structure ◽  
Electron Microscopy ◽  
Nucleation And Growth ◽  
X Ray Diffraction ◽  
X Ray ◽  
Nano Powder ◽  
Transmission Electron ◽  
Tin Oxides ◽  
Size And Morphology ◽  
Nucleation And Growth Mechanism

ITO (Indium Tin Oxides) nano-powder was prepared by the method of ammonia complexation. The chemical composition, morphology and crystal structure were characterized by X-ray diffraction (XRD) and transmission electron microscopy (TEM). Base on the nucleation and growth mechanism of the powder, the temperature of heat treatment impacting on size and morphology was discussed briefly. The results showed that the nano-ITO powder of particle size 20nm-40nm with well-pleasing particle shape and dispersion can be prepared at 800°C.

Electron Microscopy of Shock Loaded Polycrystalline Beryllium

1974 ◽  
Vol 32 ◽  
pp. 506-507 ◽  
Author(s):  
J. M. Galbraith ◽  
L. E. Murr ◽  
A. L. Stevens
Keyword(s):  
Electron Microscopy ◽  
Wave Propagation ◽  
Structural Change ◽  
Single Crystal ◽  
Diffraction Pattern ◽  
Shock Loading ◽  
Slip Systems ◽  
Compression Tests ◽  
X Ray Diffraction ◽  
X Ray

Uniaxial compression tests and hydrostatic tests at pressures up to 27 kbars have been performed to determine operating slip systems in single crystal and polycrystal1ine beryllium. A recent study has been made of wave propagation in single crystal beryllium by shock loading to selectively activate various slip systems, and this has been followed by a study of wave propagation and spallation in textured, polycrystal1ine beryllium. An alteration in the X-ray diffraction pattern has been noted after shock loading, but this alteration has not yet been correlated with any structural change occurring during shock loading of polycrystal1ine beryllium.This study is being conducted in an effort to characterize the effects of shock loading on textured, polycrystal1ine beryllium. Samples were fabricated from a billet of Kawecki-Berylco hot pressed HP-10 beryllium.

Crystal structure of an inclusion complex between chiral monoaza-15-crown-5 and S(–)-1-phenyl-ethyl ammonium percholorate

2003 ◽  
Vol 218 (5) ◽  
Author(s):  
Süheyla Özbey ◽  
F. B. Kaynak ◽  
M. Toğrul ◽  
N. Demirel ◽  
H. Hoşgören
Keyword(s):  
Crystal Structure ◽  
Inclusion Complex ◽  
Single Crystal ◽  
X Ray Diffraction ◽  
Space Group ◽  
X Ray ◽  
New Type

AbstractA new type of inclusion complex, S(–)-1 phenyl ethyl ammonium percholorate complex of R-(–)-2-ethyl - N - benzyl - 4, 7, 10, 13 - tetraoxa -1- azacyclopentadecane, has been prepared and studied by NMR, IR and single crystal X-ray diffraction techniques. The compound crystallizes in space group

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