A crystallographic analysis of the CoSi/Si(111) interface using Transmission Electron Microscopy

1990 ◽  
Vol 48 (4) ◽  
pp. 574-575
Author(s):  
A.C. Daykin ◽  
C.J. Kiely ◽  
R.C. Pond ◽  
J.L. Batstone
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Defect Structure ◽  
Room Temperature ◽  
Theoretical Method ◽  
Crystallographic Analysis ◽  
Si Substrate ◽  
Transmission Electron ◽  
Theoretical Predictions

When CoSi2 is grown onto a Si(111) surface it can form in two distinct orientations. A-type CoSi2 has the same orientation as the Si substrate and B-type is rotated by 180° degrees about the [111] surface normal.One method of producing epitaxial CoSi2 is to deposit Co at room temperature and anneal to 650°C.If greater than 10Å of Co is deposited then both A and B-type CoSi2 form via a number of intermediate silicides .The literature suggests that the co-existence of A and B-type CoSi2 is in some way linked to these intermediate silicides analogous to the NiSi2/Si(111) system. The phase which forms prior to complete CoSi2 formation is CoSi. This paper is a crystallographic analysis of the CoSi2/Si(l11) bicrystal using a theoretical method developed by Pond. Transmission electron microscopy (TEM) has been used to verify the theoretical predictions and to characterise the defect structure at the interface.

Scanning and Transmission Electron Microscopy of Human Red Blood Cells

1969 ◽  
Vol 27 ◽  
pp. 44-45
Author(s):  
A.J. Tousimis ◽  
T.R. Padden
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Blood Cells ◽  
Room Temperature ◽  
Type Specimen ◽  
New Combination ◽  
Human Red Blood Cells ◽  
Transmission Electron ◽  
Microscope Slides ◽  
Scanning Electron

The size, shape and surface morphology of human erythrocytes (RBC) were examined by scanning electron microscopy (SEM), of the fixed material directly and by transmission electron microscopy (TEM) of surface replicas to compare the relative merits of these two observational procedures for this type specimen.A sample of human blood was fixed in glutaraldehyde and washed in distilled water by centrifugation. The washed RBC's were spread on freshly cleaved mica and on aluminum coated microscope slides and then air dried at room temperature. The SEM specimens were rotary coated with 150Å of 60:40- gold:palladium alloy in a vacuum evaporator using a new combination spinning and tilting device. The TEM specimens were preshadowed with platinum and then rotary coated with carbon in the same device. After stripping the RBC-Pt-C composite film, the RBC's were dissolved in 2.5N HNO3 followed by 0.2N NaOH leaving the preshadowed surface replicas showing positive topography.

Formation of Dislocation Channels in Neutron Irradiated Molybdenum

1972 ◽  
Vol 30 ◽  
pp. 672-673
Author(s):  
S. Mahajan
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Ambient Temperature ◽  
Room Temperature ◽  
Channel Formation ◽  
Early Stages ◽  
Transmission Electron ◽  
Three Stages ◽  
Two Stages ◽  
Polycrystalline Molybdenum

The evolution of dislocation channels in irradiated metals during deformation can be envisaged to occur in three stages: (i) formation of embryonic cluster free regions, (ii) growth of these regions into microscopically observable channels and (iii) termination of their growth due to the accumulation of dislocation damage. The first two stages are particularly intriguing, and we have attempted to follow the early stages of channel formation in polycrystalline molybdenum, irradiated to 5×1019 n. cm−2 (E > 1 Mev) at the reactor ambient temperature (∼ 60°C), using transmission electron microscopy. The irradiated samples were strained, at room temperature, up to the macroscopic yield point.Figure 1 illustrates the early stages of channel formation. The observations suggest that the cluster free regions, such as A, B and C, form in isolated packets, which could subsequently link-up to evolve a channel.

Synthesis and TEM study of Ag–In–(Eu, Ce) ternary approximants

2009 ◽  
Vol 224 (1-2) ◽  
Author(s):  
Kazue Nishimoto ◽  
Miki Muraki ◽  
Ryuji Tamura
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Room Temperature ◽  
Transmission Electron

AbstractTernary Ag–In–(Eu, Ce) 1/1 approximants are synthesized and their structures are studied by transmission electron microscopy (TEM). For both the approximants, superlattice spots are clearly observed at room temperature, and the superstructures of the Ag–In–(Eu, Ce) approximants are found to be similar to those of Cd

Preparation of Straight and Orderly Polypyrrole Microrods through Soft Template Methods

2011 ◽  
Vol 306-307 ◽  
pp. 679-683
Author(s):  
Li Bo Sun ◽  
Yuan Chang Shi ◽  
Lin Ya Chu ◽  
Bing Chang Zhang ◽  
Jiu Rong Liu
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Cetyltrimethylammonium Bromide ◽  
Growth Process ◽  
Room Temperature ◽  
Oxidative Polymerization ◽  
Soft Template ◽  
Microemulsion System ◽  
Transmission Electron ◽  
The Impact

The straight and orderly microrods of polypyrrole(PPy) was synthesized in a microemulsion system consisted of cetyltrimethylammonium bromide(CTAB), n-pentanol, water and pyrrole by chemical oxidative polymerization, in which CTAB was used as soft templates and APS was used as the oxidant. Fourier-transform infrared spectroscopy (FTIR) was used to characterize the structure of the PPy microrods. Transmission electron microscopy (TEM) and high resolution transmission electron microscopy (HRTEM) was used to characterize the morphology of the samples. We discussed the impact of temperature, the adding way of the oxidant, the amount of cosurfactant n-pentanol to the morphology of PPy microrods. The results showed that straight and orderly PPy microrods with a diameter about 300nm and a length up to 20μm were synthesized when the temperature was kept at room temperature (25°C), the dropping time of APS was more than 1.5h, the ratio of CTAB to n-pentanol was 0.6:1, and the polymerization time was about 24h. We studied the growth process of PPy microrods by HTEM analysis. HTEM images revealed that the growth process of PPy changed from hollow microrods, semi-hollow microrods, and finally solid microrods.

Nanotwinned Surface on a Ternary Titanium Alloy with Increased Hardness Induced under Nanoindentations

2016 ◽  
Vol 874 ◽  
pp. 323-327
Author(s):  
Hong Xiu Zhou ◽  
Ming Lei Li ◽  
Neng Dong Duan ◽  
Bo Wang ◽  
Zhi Feng Shi ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Surface Roughness ◽  
Titanium Alloy ◽  
Chemical Mechanical Polishing ◽  
Material Removal ◽  
Room Temperature ◽  
Chemical Reagents ◽  
Transmission Electron ◽  
High Temperature High Pressure

A nanotwinned surface is formed on a titanium alloy under nanoindentations. Prior to nanoindentation, blocks of a ternary titanium alloy are machined by chemical mechanical polishing. The surface roughness Ra and peak-to-valley values are 1.135 nm and 8.82 nm, respectively. The hardness in the indented surface is greatly increased, indicated from the load-displacement curves compared to the polished surfaces. Nanotwins are confirmed using transmission electron microscopy. The nanotwinned surface is uniformly generated by nanoindentations at room temperature, which is different from previous findings, in which high temperature, high pressure, or chemical reagents are usually used. The nanotwinned surface is produced by pure mechanical stress, neither material removal nor addition.

Asymmetric Cracking in Znse/ZnSxSel−x Superlattices Grown by Molecular Bean Epitaxy

1987 ◽  
Vol 102 ◽  
Author(s):  
Richard J. Dalby ◽  
John Petruzzello
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Thermal Expansion ◽  
Molecular Beam Epitaxy ◽  
Molecular Beam ◽  
Lattice Mismatch ◽  
Sulfur Concentration ◽  
Transmission Electron ◽  
Theoretical Predictions ◽  
Superlattice Layer

ABSTRACTOptical and transmission electron microscopy have been used to study cracks appearing in ZnSe/ZnSxSe1−x (x ∼ 0.38) superlattices grown by Molecular Beam Epitaxy. It Is shown that when a fracture occurs it is confined, in most cases, to the superlattice and propagates along <011> cleavage directions in these <001> oriented epilayers. Cracks were not observed in all superlattices and their onset is discussed in relation to sulfur concentration, overall superlattice height, individual superlattice layer thicknesses, and stress, tensile or compressive, due to lattice mismatch and thermal expansion differences between buffer layer and superlattice. It was found that by adjusting the controllable parameters, cracks in the superlattices could be eliminated. Orientation and density of these features have been related to asynnmetric cracking associated with the zincblende structure of these II-VI materials. Experimental results are shown to be in agreement with theoretical predictions of critical heights for the onset of cracking.

scholarly journals Characterization of Gaas/Si/GaAs Heterointerfaces

1989 ◽  
Vol 148 ◽  
Author(s):  
Zuzanna Liliental-Weber ◽  
Raymond P. Mariella
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Low Temperature ◽  
Defect Density ◽  
Si Substrate ◽  
Reverse Polarity ◽  
Si Substrates ◽  
Transmission Electron ◽  
Metal Semiconductor Metal

ABSTRACTTransmission electron microscopy of GaAs grown on Si for metal-semiconductor-metal photodetectors is presented in this paper. Two kinds of samples are compared: GaAs grown on a 15 Å Si epilayer grown on GaAs, and GaAs grown at low temperature (300°C) on Si substrates. It is shown that the GaAs epitaxial layer grown on thin Si layer has reverse polarity to the substrate (antiphase relation). Higher defect density is observed for GaAs grown on Si substrate. This higher defect density correlates with an increased device speed, but with reduced sensitivity.

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