Micropipe-induced birefringence in 6H silicon carbide

2009 ◽  
Vol 43 (1) ◽  
pp. 122-133 ◽  
Author(s):  
T. Ouisse ◽  
D. Chaussende ◽  
L. Auvray
Keyword(s):  
Electron Microscopy ◽  
Residual Stress ◽  
Transmission Electron Microscopy ◽  
Silicon Carbide ◽  
Burgers Vector ◽  
X Ray ◽  
Induced Stress ◽  
Transmission Electron ◽  
Theory And Experiment ◽  
Good Agreement

The micropipe-induced birefringence of 6H silicon carbide (SiC) is measured and quantitatively modelled. A good agreement can be obtained between theory and experiment, provided that background residual stress is added to the local dislocation-induced stress. Observations are compatible with or predictable from the Burgers vector values, and birefringence is shown to be an interesting tool for probing the nature of the dislocations associated withe.g.micropipes; it is also faster than and complementary to the more involved techniques of transmission electron microscopy or X-ray topography.

Dislocation-Induced Birefringence in Silicon Carbide

2009 ◽  
Vol 615-617 ◽  
pp. 271-274
Author(s):  
Thierry Ouisse ◽  
Didier Chaussende ◽  
Laurent Auvray ◽  
Etienne Pernot ◽  
Roland Madar
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Silicon Carbide ◽  
Uniaxial Stress ◽  
Burgers Vector ◽  
Induced Stress ◽  
Transmission Electron ◽  
Theory And Experiment ◽  
Good Agreement

The dislocation-induced birefringence of Silicon Carbide (SiC) is analytically and quantitatively modelled by using the adequate SiC data. A good agreement can be obtained between theory and experiment, provided that a background residual (uniaxial) stress is added to the local dislocation-induced stress. Observations are compatible with or predictable from the Burgers vector values, so that birefringence reveals an interesting tool for probing the nature of the dislocations associated, e.g., to micropipes, also faster than and complementary to the more involved transmission electron microscopy (TEM) technique.

Characterization Of Single Crystal Epitaxial Aluminum Nitride Thin Films On Sapphire, Silicon Carbide And Silicon Substrates By X-Ray Double Crystal Diffractometry And Transmission Electron Microscopy

1995 ◽  
Vol 39 ◽  
pp. 645-651
Author(s):  
J. Chaudhuri ◽  
R. Thokala ◽  
J. H. Edgar ◽  
B. S. Sywe
Keyword(s):  
Thin Film ◽  
Electron Microscopy ◽  
Thin Films ◽  
Residual Stress ◽  
Transmission Electron Microscopy ◽  
Silicon Carbide ◽  
Defect Density ◽  
Double Crystal ◽  
X Ray ◽  
Transmission Electron

Epitaxial AIN thin films grown on sapphire, silicon and silicon carbide substrates were studied using x-ray double crystal diffractometry and transmission electron microscopy to compare the structure, residual stress and defect concentration in these thin films. The AIN thin films was found to have a wurtzite type of structure with a small distortion in lattice parameters which results in a small residual stress of the order of 109 dynes/cm2 in the film. The strain due to lattice parameter mismatch between the substrate and film is too small to account for the residual stress present. The calculated stress from the difference in thermal expansion coefficients between the film and substrate agrees well with the experimental values. Both the x-ray and transmission electron microscopy measurements indicate a low defect density in the AIN thin film grown on 6H-SiC substrate which could be attributed to the small difference in lattice parameters between AIN and 6H-SiC. The defect density in the AIN thin film grown on other substrates were considerably higher. This is the first report of the successful growth of single crystal AIN thin films with such a low concentration of defect density.

Investigation of Defect Formation in 4H-SiC(0001) and (000-1) Epitaxy

2008 ◽  
Vol 600-603 ◽  
pp. 267-272 ◽  
Author(s):  
Hidekazu Tsuchida ◽  
Isaho Kamata ◽  
Masahiro Nagano
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Defect Formation ◽  
Grazing Incidence ◽  
Microscopic Structure ◽  
Threading Dislocation ◽  
Simultaneous Generation ◽  
Burgers Vector ◽  
X Ray ◽  
Transmission Electron

Defect formation in 4H-SiC(0001) and (000-1) epitaxy is investigated by grazing incidence synchrotron reflection X-ray topography and transmission electron microscopy. Frank-type faults, which are terminated by four Frank partials with a 1/4[0001] type Burgers vector with the same sign on four different basal planes, are confirmed to be formed by conversion of a 1c threading edge dislocation (TSD) in the substrate as well as simultaneous generation of a 1c TSD during epitaxy. The collation between the topography appearance and the microscopic structure and the variety of Frank faults are shown. Formation of carrot defects and threading dislocation clusters are also investigated.

scholarly journals Влияние термообработки на свойства композитных кремний-углеродных анодов для литий-ионных аккумуляторов

2020 ◽  
Vol 46 (3) ◽  
pp. 14
Author(s):  
Е.В. Астрова ◽  
А.В. Парфеньева ◽  
А.М. Румянцев ◽  
В.П. Улин ◽  
М.В. Байдакова ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Silicon Carbide ◽  
Diffraction Analysis ◽  
Annealing Temperature ◽  
Argon Atmosphere ◽  
X Ray Diffraction ◽  
X Ray ◽  
Transmission Electron ◽  
Lithium Alloys

The effect of annealing temperature in argon atmosphere on the ability of Si-C nanocomposites to reversibly insert lithium was investigated. It was found that the higher the annealing temperature during the formation of the composite, the lower is the capacitance of the electrode made from it. X-ray diffraction analysis and transmission electron microscopy reveal that the reason of the capacitance decrease is formation at T  1100°C of silicon carbide of cubic modification -SiC, inactive with respect to the formation of lithium alloys or intercalates.

scholarly journals Microstructure Investigation of WC-Based Coatings Prepared by HVOF onto AZ31 Substrate

Materials ◽  
2021 ◽  
Vol 15 (1) ◽  
pp. 40
Author(s):  
Ewa Jonda ◽  
Leszek Łatka ◽  
Anna Tomiczek ◽  
Marcin Godzierz ◽  
Wojciech Pakieła ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Residual Stress ◽  
Transmission Electron Microscopy ◽  
Magnesium Alloy ◽  
Xrd Analysis ◽  
X Ray Diffraction ◽  
X Ray ◽  
Magnesium Alloy Az31 ◽  
Transmission Electron ◽  
Low Elastic Modulus

In this paper, three commercial cermet powders, WC-Co-Cr, WC-Co and WC-Cr3C2-Ni, were sprayed by the High Velocity Oxy Fuel (HVOF) method onto magnesium alloy AZ31 substrate. The coatings were investigated in terms of their microstructure, phase analysis and residual stress. The manufactured coatings were analyzed extensively using optical microscopy (OM), X-ray diffraction (XRD), scanning (SEM) and transmission electron microscopy (TEM). Based on microstructure studies, it was noted that the coatings show satisfactory homogeneity. XRD analysis shows that in WC-Co, WC-Co-Cr and WC-Cr3C2-Ni coatings, main peaks are related to WC. Weaker peaks such as W2C, Co0.9W0.1, Co and W for WC-Co and W2C, Cr3C2 and Cr7C3 for WC-Cr3C2-Ni also occur. In all cermet coatings, linear stress showed compressive nature. In WC-Co and WC-Cr3C2-Ni, residual stress had a similar value, while in WC-Co-Cr, linear stress was lower. It was also proved that spraying onto magnesium substrate causes shear stress in the WC phase, most likely due to the low elastic modulus of magnesium alloy substrate.

SYNTHESIZED “IN SITU” IN REVERSE MICELLES OF SILVER-SULFIDE SEMICONDUCTORS

1996 ◽  
Vol 03 (01) ◽  
pp. 1215-1218 ◽  
Author(s):  
M.P. PILENI ◽  
L. MOTTE ◽  
F. BILLOUDET ◽  
C. PETIT
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Reverse Micelles ◽  
Silver Sulfide ◽  
X Ray ◽  
X Ray Scattering ◽  
Transmission Electron ◽  
Nanosize Particles ◽  
Good Agreement

Functionalized reverse micelles are used to control the size of silver sulfide, Ag 2 S , nanosize particles. The size of the crystallites varies linearly with the water content from 2 to 10 nm. The particles have been coated with dodecanethiol and extracted from micelles. The size of the particles dispersed in heptane has been determined by small-angles x-ray scattering (SAXS) experiments and compared to those obtained by transmission electron microscopy (TEM). A good agreement between results is obtained by these two techniques. A drop of particles previously dispersed in heptane is dried on a carbon grill. A network of the particles forming monolayers of crystallites in a hexagonal distribution appears.

Synthesis of Silicon Carbide in Hypervelocity Plasma Jet

2015 ◽  
Vol 1085 ◽  
pp. 38-43
Author(s):  
Dmitry S. Nikitin ◽  
Alexander A. Sivkov ◽  
Alexander Ya. Pak ◽  
Ilyas A. Rakhmatullin
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Silicon Carbide ◽  
Plasma Jet ◽  
Synthesis Product ◽  
Composition Change ◽  
X Ray ◽  
Carbon Onion ◽  
Transmission Electron ◽  
Cubic Silicon Carbide

Results of plasmodynamic synthesis of silicon carbide nanopowders are given in the article. Studies of the synthesis product by X-ray diffractometry and transmission electron microscopy indicated that the product consists mainly of cubic silicon carbide and also includes cubic silicon, ultradispersed graphite and carbon onion-like structures. It was shown that a phase composition change in the synthesis product is possible by changing the ratio of precursor mixture.

Phase Transformations in Ti-7w/oMo-3w/oMe Alloy

1974 ◽  
Vol 32 ◽  
pp. 514-515
Author(s):  
S. Fujishiro
Keyword(s):  
Electron Microscopy ◽  
Mechanical Properties ◽  
Transmission Electron Microscopy ◽  
Tensile Strength ◽  
Mechanical Processing ◽  
Ray Method ◽  
X Ray ◽  
Transmission Electron ◽  
Water Quench ◽  
Alpha Beta

The mechanical properties of three titanium alloys (Ti-7Mo-3Al, Ti-7Mo- 3Cu and Ti-7Mo-3Ta) were evaluated as function of: 1) Solutionizing in the beta field and aging, 2) Thermal Mechanical Processing in the beta field and aging, 3) Solutionizing in the alpha + beta field and aging. The samples were isothermally aged in the temperature range 300° to 700*C for 4 to 24 hours, followed by a water quench. Transmission electron microscopy and X-ray method were used to identify the phase formed. All three alloys solutionized at 1050°C (beta field) transformed to martensitic alpha (alpha prime) upon being water quenched. Despite this heavily strained alpha prime, which is characterized by microtwins the tensile strength of the as-quenched alloys is relatively low and the elongation is as high as 30%.

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