TEM Study of Bulk AlN Growth by Physical Vapor Transport

1999 ◽  
Vol 595 ◽  
Author(s):  
W.L. Sarney ◽  
L. Salamanca-Riba ◽  
T. Hossain ◽  
P. Zhou ◽  
H.N. Jayatirtha ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Auger Electron ◽  
Film Growth ◽  
Structural Characteristics ◽  
Columnar Structure ◽  
Vapor Transport ◽  
Physical Vapor Transport ◽  
Nitride Film ◽  
X Ray Diffraction ◽  
X Ray

AbstractWe are attempting to grow bulk AlN that would be suitable as a substrate for nitride film growth. Bulk AlN films were grown by physical vapor transport on 3.5° offaxis and on-axis 6H SiC seed crystals and characterized by TEM, x-ray-diffraction, Auger electron microscopy, and SEM. TEM images show that the bulk AlN does not have the columnar structure typically seen in AlN films grown by MOCVD. Although further optimization is required before the bulk AlN is suitable as a substrate, we find that the structural characteristics achieved thus far indicate that quality bulk AlN substrates may be obtained in the future.

scholarly journals TEM Study of Bulk AlN Growth by Physical Vapor Transport

2000 ◽  
Vol 5 (S1) ◽  
pp. 384-390
Author(s):  
W.L. Sarney ◽  
L. Salamanca-Riba ◽  
T. Hossain ◽  
P. Zhou ◽  
H.N. Jayatirtha ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Auger Electron ◽  
Film Growth ◽  
Structural Characteristics ◽  
Columnar Structure ◽  
Vapor Transport ◽  
Physical Vapor Transport ◽  
Nitride Film ◽  
X Ray Diffraction ◽  
X Ray

We are attempting to grow bulk AlN that would be suitable as a substrate for nitride film growth. Bulk AlN films were grown by physical vapor transport on 3.5° off-axis and on-axis 6H SiC seed crystals and characterized by TEM, x-ray-diffraction, Auger electron microscopy, and SEM. TEM images show that the bulk AlN does not have the columnar structure typically seen in AlN films grown by MOCVD. Although further optimization is required before the bulk AlN is suitable as a substrate, we find that the structural characteristics achieved thus far indicate that quality bulk AlN substrates may be obtained in the future.

A High Resolution Study of G.P. Zones in Aluminum - 4.2 at % Silver

1982 ◽  
Vol 40 ◽  
pp. 722-723 ◽  
Author(s):  
R. Gronsky
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
High Resolution ◽  
Computer Simulations ◽  
Structural Characteristics ◽  
X Ray Diffraction ◽  
X Ray ◽  
Transmission Electron ◽  
Resolution Study

The phenomenon of clustering in Al-Ag alloys has been extensively studied since the early work of Guinierl, wherein the pre-precipitation state was characterized as an assembly of spherical, ordered, silver-rich G.P. zones. Subsequent x-ray and TEM investigations yielded results in general agreement with this model. However, serious discrepancies were later revealed by the detailed x-ray diffraction - based computer simulations of Gragg and Cohen, i.e., the silver-rich clusters were instead octahedral in shape and fully disordered, atleast below 170°C. The object of the present investigation is to examine directly the structural characteristics of G.P. zones in Al-Ag by high resolution transmission electron microscopy.

OMCVD of thin films from metal diketonates and triphenylbismuth

1990 ◽  
Vol 5 (6) ◽  
pp. 1169-1175 ◽  
Author(s):  
A. D. Berry ◽  
R. T. Holm ◽  
M. Fatemi ◽  
D. K. Gaskill
Keyword(s):  
Electron Microscopy ◽  
Vapor Deposition ◽  
Atmospheric Pressure ◽  
Electron Spectroscopy ◽  
Auger Electron ◽  
Chemical Vapor ◽  
X Ray Diffraction ◽  
Strontium Barium ◽  
X Ray ◽  
Scanning Electron

Films containing the metals copper, yttrium, calcium, strontium, barium, and bismuth were grown by organometallic chemical vapor deposition (OMCVD). Depositions were carried out at atmospheric pressure in an oxygen-rich environment using metal beta-diketonates and triphenylbismuth. The films were characterized by Auger electron spectroscopy, Nomarski and scanning electron microscopy, and x-ray diffraction. The results show that films containing yttrium consisted of Y2O3 with a small amount of carbidic carbon, those with copper and bismuth were mixtures of oxides with no detectable carbon, and those with calcium, strontium, and barium contained carbonates. Use of a partially fluorinated barium beta-diketonate gave films of BaF2 with small amounts of BaCO3.

Growth of Oriented Tin Oxide Thin Films from an Organctin Compound by Spray Pyrolysisxf

1992 ◽  
Vol 271 ◽  
Author(s):  
Isao Yag ◽  
Shoji Kaneko
Keyword(s):  
Electron Microscopy ◽  
Tin Oxide ◽  
Film Growth ◽  
Growth Parameters ◽  
Optimum Growth ◽  
X Ray Diffraction ◽  
X Ray ◽  
Tin Oxide Films ◽  
Heated Glass ◽  
Scanning Electron

ABSTRACTTin oxide films were grown from di-n-butyltin diacetate on a heated glass substrate by a pneumatic spraying system The effects of various film growth parameters. i.e solvent, solution feed rate, film thickness, and film growth rate on the microstructures of the films were studied by X-ray diffraction and scanning electron microscopy The SnO2 films of the (200) plane were grown by the optimum growth parameters

Structural Characterization of the Growth Front of 4H-SiC Boules Grown Using the Physical Vapor Transport Growth Method

2018 ◽  
Vol 924 ◽  
pp. 15-18
Author(s):  
Masashi Sonoda ◽  
Kentaro Shioura ◽  
Takahiro Nakano ◽  
Noboru Ohtani ◽  
Masakazu Katsuno ◽  
...  
Keyword(s):  
High Resolution ◽  
Surface Morphology ◽  
Defect Structure ◽  
Growth Front ◽  
Vapor Transport ◽  
Physical Vapor Transport ◽  
X Ray Diffraction ◽  
X Ray ◽  
Growth Method

The defect structure at the growth front of 4H-SiC boules grown using the physical vapor transport (PVT) method has been investigated using high resolution x-ray diffraction and x-ray topography. The crystal parameters such as the c-lattice constant exhibited characteristic variations across the growth front, which appeared to be caused by variation in surface morphology of the as-grown surface of the boules rather than the defect structure underneath the surface. X-ray topography also revealed that basal plane dislocations are hardly nucleated at the growth front during PVT growth of 4H-SiC crystals.

scholarly journals Transmission Electron Microscopy and X-ray Diffraction Investigation of the Microstructure of Nanoscale Multilayer TiAlN/VN Grown by Unbalanced Magnetron Deposition

2004 ◽  
Vol 19 (4) ◽  
pp. 1093-1104 ◽  
Author(s):  
Q. Luo ◽  
D.B. Lewis ◽  
P.Eh. Hovsepian ◽  
W-D. Münz
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Growth Model ◽  
Growth Front ◽  
Columnar Structure ◽  
Layer Growth ◽  
X Ray Diffraction ◽  
X Ray ◽  
Transmission Electron ◽  
Unbalanced Magnetron

Cubic NaCl-B1 structured multilayer TiAlN/VN with a bi-layer thickness of approximately 3 nm and atomic ratios of (Ti+Al)/V = 0.98 to 1.15 and Ti/V = 0.55 to 0.61 were deposited by unbalanced magnetron sputtering at substrate bias voltages between -75 and -150 V. In this paper, detailed transmission electron microscopy and x-ray diffraction revealed pronounced microstructure changes depending on the bias. At the bias -75 V, TiAlN/VN followed a layer growth model led by a strong (110) texture to form a T-type structure in the Thornton structure model of thin films, which resulted in a rough growth front, dense columnar structure with inter-column voids, and low compressive stress of -3.8 GPa. At higher biases, the coatings showed a typical Type-II structure following the strain energy growth model, characterized by the columnar structure, void-free column boundaries, smooth surface, a predominant (111) texture, and high residual stresses between -8 and -11.5 GPa.

Bifunctional Electrocatalytic Films with Gold Nanoparticles and Metalloporphyrin: Preparation and Characterization

2001 ◽  
Vol 676 ◽  
Author(s):  
Wenjun Yang ◽  
Xiaoyuan Li ◽  
Nai-Teng Yu
Keyword(s):  
Electron Microscopy ◽  
Gold Nanoparticles ◽  
Absorption Spectroscopy ◽  
Tin Oxide ◽  
Film Growth ◽  
Layer By Layer ◽  
X Ray Diffraction ◽  
X Ray ◽  
Layer Assembly ◽  
Scanning Electron

ABSTRACTBifunctional electrocatalytic films were prepared employing a layer-by-layer assembly approach. The cation, metalloporphyrin (MP), and the anion, potassium tetrachloroaurate (KAuCl4) were alternatively assembled on glass or indium-doped tin oxide (ITO) supports. The assembled AuCl4- ions were then converted to gold nanoparticles (Aun) under the exposure to ultraviolet light. Film growth at each adsorption step was monitored by UV-Vis absorption spectroscopy and cyclic voltammetry (CV). The formation of gold nanoparticles was characterized by UV-Vis absorption spectroscopy, X-ray diffraction (XRD) and scanning electron microscopy (SEM). Bifunctional electrocatalytic activity of the film was demonstrated in the oxidative detection of nitric oxide (NO) over Aun and the reductive detection of oxygen (O2) over Co(II)P in the same CV scan.

Structural and Electrical Characterization of the Initial Stage of Physical Vapor Transport Growth of 4H-SiC Crystals

2015 ◽  
Vol 821-823 ◽  
pp. 90-95
Author(s):  
Tatsuya Takahashi ◽  
Chikashi Ohshige ◽  
Noboru Ohtani ◽  
Masakazu Katsuno ◽  
Tatsuo Fujimoto ◽  
...  
Keyword(s):  
Raman Scattering ◽  
Grown Crystal ◽  
Defect Formation ◽  
Vapor Transport ◽  
Physical Vapor Transport ◽  
Formation Mechanisms ◽  
X Ray Diffraction ◽  
X Ray ◽  
Initial Stage ◽  
Crystal Seed

Defect formation during the initial stage of physical vapor transport (PVT) growth of 4H-SiC crystals in the [000-1] and [11-20] directions was investigated by x-ray diffraction, defect-selective etching, and micro Raman scattering imaging. X-ray diffraction studies showed that the growths in the [000-1] and [11-20] directions exhibited markedly different behaviors with respect to the defect formation during the initial stage of growth. While a characteristic lattice plane bending was observed for the PVT growth along [000-1], a tilted domain structure was revealed near the grown crystal/seed interface for the growth in the [11-20] direction. Micro Raman scattering imaging revealed that nitrogen enrichment occurred near the grown crystal/seed interface and was associated with compressive stress parallel to the interface. Based on the results, the defect formation mechanisms during the initial stage of PVT growth of 4H-SiC are discussed.

scholarly journals Obtention and Characterization of Ferrous Chloride FeCl2·4H2O from Pickling Waste Liquors

2021 ◽  
Author(s):  
Lorena Alcaraz ◽  
Belén Sotillo ◽  
José F. Marco ◽  
Francisco J. Alguacil ◽  
Paloma Fernández ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Structural Characteristics ◽  
Morphological Characteristics ◽  
Aged Sample ◽  
X Ray Diffraction ◽  
Ferrous Chloride ◽  
Photoluminescence Study ◽  
X Ray ◽  
Scanning Electron

As a hazardous waste, pickling waste liquor must be properly treated. An alternative consists in promoting the formation of ferrous salts from this residue, due to its higher ferrous content. Since FeCl2·4H2O is widely used in several applications, obtaining pure crystals of this material appears to be an interesting prospect. However, this compound has scarcely been investigated. In the present work, FeCl2·4H2O crystals have been obtained from pickling waste liquors. Their structural and morphological characteristics have been investigated by X-ray diffraction, scanning electron microscopy as well as Mössbauer spectroscopy. In addition, the photoluminescence study of the obtained samples was also assessed. It was observed that after some aging time, the obtained crystals change in colour from green to more yellowish. So, the aged sample has also been evaluated, and their structural characteristics are compared with the original crystals. Despite this, the obtained crystals exhibit a FeCl2·4H2O structure, which is not modified with the aging of the sample.

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