TEM Investigation of Microwave Joined Si-SiC/Al/Si-SiC and α-SiC/Al/α-SiC.

1993 ◽  
Vol 314 ◽  
Author(s):  
S. Arunajatesan ◽  
A. H. Carim ◽  
T. Y. Yiin ◽  
V. K. Varadan
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Electron Probe Microanalysis ◽  
Electron Probe ◽  
Intimate Contact ◽  
Strength Data ◽  
Transmission Electron

AbstractElectron probe microanalysis (EPMA) and transmission electron microscopy (TEM) have been used to examine the SiC/Al interfaces in microwave joined Si-SiC/Al/Si-SiC and α-SiC/Al/α-SiC. Both the SiC/Al interfaces display intimate contact between the ceramic and metal and are free of porosity. EPMA of the α-SiC/Al/α-SiC joints reveals that no Al has diffused into the bulk α-SiC, unlike the reported diffusion of Al in Si-SiC/Al/Si-SiC. The TEM investigations show that while the Si-SiC/Al/Si-SiC interface is reaction-free, the α-SiC/Al/α-SiC joint contains Si at the interface. The TEM findings are correlated to the strength data available on these joints and the possible reasons for the presence of Si in the absence of Al4C3 in the α-SiC/Al/α-SiC joint are discussed.

Microstructure and growth of joins in melt-textured YBa2Cu3O7−δ

2001 ◽  
Vol 16 (8) ◽  
pp. 2298-2305 ◽  
Author(s):  
A. D. Bradley ◽  
W. Lo ◽  
M. Mironova ◽  
N. H. Babu ◽  
D. A. Cardwell ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Liquid Phase ◽  
Grain Boundary ◽  
Electron Probe ◽  
High Quality ◽  
Strongly Coupled ◽  
External Agent ◽  
Transmission Electron

Joining of melt-textured YBa2Cu3O7-δ (Y123) grains has been achieved without use of an external agent. The technique uses barium-cuprate liquid phase released from platelet boundaries to mediate the growth of Y123 at the interface between two grains. The epitaxial nature and high quality of the growth was determined by optical and transmission electron microscopy. The composition of Ba–Cu–O phases found in some parts of the joins was determined by electron probe microanalysis. A clean low-angle join was found to consist of a grain boundary with dislocation networks and facets. Transport critical current measurements on this type of join revealed strongly coupled behavior. The technique shows promise for the joining of melt-textured material for power engineering applications.

Few-nanometer femtosecond electron probe pulses in ultrafast transmission electron microscopy

2016 ◽  
Author(s):  
Armin Feist ◽  
Katharina E. Echternkamp ◽  
Reiner Bormann ◽  
Nara Rubiano da Silva ◽  
Marcel Möller ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Electron Probe ◽  
Transmission Electron

Electron Probe Microanalysis Of Spironolactone Bodies

1999 ◽  
Vol 5 (S2) ◽  
pp. 1288-1289
Author(s):  
J.P. McNeil ◽  
J.E. Carter ◽  
C.W. Boudreaux ◽  
F. McDonald ◽  
J.A. Tucker ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Adrenal Gland ◽  
Electron Probe Microanalysis ◽  
Electron Probe ◽  
Zona Glomerulosa ◽  
Sem Analysis ◽  
Transmission Electron ◽  
Excess Production ◽  
Glomerulosa Cells ◽  
Zona Glomerulosa Cells

Spironolactone bodies (SB) were first described in 1963 by Janigan. These laminated, whorled structures are seen in cells of the adrenal zona glomerulosa in patients treated with the drug spironolactone. Spironolactone is an aldosterone antagonist. Hyperaldosteronism may result from excess production by the adrenal cortex. By both light microscopy and transmission electron microscopy (TEM), SB have a distinctive, laminated appearance. Kovacs, et al. observed that SB are composed of cellular constituents. To our knowledge, SB have not been analyzed using scanning electron microscopy (SEM) and electron probe microanalysis technology.An adrenal gland with a 1 cm cortical mass was removed from a 39 year old female and received in 10% buffered formalin. Histologic examination of the mass showed a monotonous population of cells recapitulating zona glomerulosa cells. Intracytoplasmic structures compatible with SB were identified. Portions of the adrenal gland were processed for TEM and SEM analysis.

Write-Erase Mechanism of Indium-Antimony Optical Disk Medium

1986 ◽  
Vol 74 ◽  
Author(s):  
Y. Goto ◽  
K. Utsumi ◽  
A. Ushioda ◽  
I. Tsugawa ◽  
N. Koshino
Keyword(s):  
Electron Microscopy ◽  
Phase Diagram ◽  
Transmission Electron Microscopy ◽  
Electron Probe ◽  
Crystal Size ◽  
Optical Disk ◽  
Grain Sizes ◽  
Zinc Blende ◽  
Transmission Electron ◽  
The Difference

AbstractWritten and erased bits of the In-Sb phase change type optical disk medium were studied using transmission electron microscopy (TEN) and electron probe microanalysis (EPMA). Both the bits were separated into inner and outer areas and were composed of only rhombohedral Sb crystals and zinc blende In50Sb50 crystals. The difference between the two bits were in crystal size and atomic distribution of the inner area. Models of the writing and erasing processes were derived from these observations and the In-Sb phase diagram. With these models, the thicknesses, grain sizes and optical contrasts of the both bits were consistently explained.

Simplifying Electron Beam Channeling in Scanning Transmission Electron Microscopy (STEM)

2017 ◽  
Vol 23 (4) ◽  
pp. 794-808 ◽  
Author(s):  
Ryan J. Wu ◽  
Anudha Mittal ◽  
Michael L. Odlyzko ◽  
K. Andre Mkhoyan
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Electron Beam ◽  
Angular Distribution ◽  
Electron Probe ◽  
Scanning Transmission Electron Microscopy ◽  
Probe Intensity ◽  
Scanning Transmission Electron ◽  
Transmission Electron ◽  
Scanning Transmission

AbstractSub-angstrom scanning transmission electron microscopy (STEM) allows quantitative column-by-column analysis of crystalline specimens via annular dark-field images. The intensity of electrons scattered from a particular location in an atomic column depends on the intensity of the electron probe at that location. Electron beam channeling causes oscillations in the STEM probe intensity during specimen propagation, which leads to differences in the beam intensity incident at different depths. Understanding the parameters that control this complex behavior is critical for interpreting experimental STEM results. In this work, theoretical analysis of the STEM probe intensity reveals that intensity oscillations during specimen propagation are regulated by changes in the beam’s angular distribution. Three distinct regimes of channeling behavior are observed: the high-atomic-number (Z) regime, in which atomic scattering leads to significant angular redistribution of the beam; the low-Zregime, in which the probe’s initial angular distribution controls intensity oscillations; and the intermediate-Zregime, in which the behavior is mixed. These contrasting regimes are shown to exist for a wide range of probe parameters. These results provide a new understanding of the occurrence and consequences of channeling phenomena and conditions under which their influence is strengthened or weakened by characteristics of the electron probe and sample.

SiC TO SiC WAFER BONDING

2002 ◽  
Vol 742 ◽  
Author(s):  
G. N. Yushin ◽  
A. V. Kvit ◽  
R. Collazo ◽  
Z. Sitar
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Cross Section ◽  
Wafer Bonding ◽  
Extended Defects ◽  
Electrical Measurements ◽  
High Crystalline Quality ◽  
Intimate Contact ◽  
Transmission Electron ◽  
Sic Wafer

ABSTRACTSiC wafers with an RMS roughness of 1.5 nm were bonded in a dedicated ultrahigh vacuum bonding chamber. Successful fusion of wafers was observed at temperatures as low as 800°C under a uniaxial mechanical stress of 20 MPa. Cross-section transmission electron microscopy (XTEM) of a specimen bonded at 1100°C revealed parts of the interface where wafers were in intimate contact, while other parts contained an up to 3 nm thick amorphous carbon interlayer. The bonded SiC retained its high crystalline quality; no extended defects emanating from the interface were observed within the sampling region. Electrical measurements showed that the azimuthal orientation of the bonded couple significantly influences the electrical character of the junction.

Phosphore, calcium, silicium et fer dans des cristaux, extraits de graines sèches de Raphanus

1984 ◽  
Vol 62 (11) ◽  
pp. 2394-2402 ◽  
Author(s):  
Louis Genevès ◽  
Jacques Rutin ◽  
Sylvain Halpern
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Electron Beam ◽  
Electron Probe ◽  
Average Diameter ◽  
Transmission Electron ◽  
Polymorphic Crystals ◽  
Parenchyma Cells ◽  
Ultrathin Sections ◽  
Wavelength Dispersive Spectrometer

Samples were taken from dry seeds of radish and fixed in glutaraldehyde. Ultrathin sections were observed without contrasting treatment. From cotyledonary parenchyma, it was possible to obtain powders or prints, which were observed by transmission electron microscopy. They showed several types of crystals. In the ultrathin sections of parenchyma cells, the crystals are included in globoids. Electron probe microanalysis with a wavelength dispersive spectrometer (Camebax microprobe) showed that they were rich in P, Ca, and Mg. In the powders and the prints, several polymorphic crystals, of varied sizes, were observed; these were sensitive to the electron beam. Some have relatively high ratios in Ca, lower ratios of S, and other elements, such as Si. Others possessed high ratios of Si with other elements, such as Ca and Al. The latter were less dense, more stable under the beam and their average diameter was smaller. Other crystals were smaller (some tenths of a micrometre). They were electron dense and very stable. Some of these were rich in Fe and could contain other elements (among others Si, Ca and P).

Techniques for Transmission Electron Microscopy of Fiber-Matrix Interfaces in Aluminum Alloy-Boron Composites by Ion Erosio

1971 ◽  
Vol 29 ◽  
pp. 204-205
Author(s):  
G. G. Shaw
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Aluminum Alloy ◽  
Electron Beam ◽  
Pure Aluminum ◽  
Ion Milling ◽  
Transmission Electron ◽  
Fiber Matrix ◽  
Ion Erosion ◽  
Row Of Fibers

The morphology and composition of the fiber-matrix interface can best be studied by transmission electron microscopy and electron diffraction. For some composites satisfactory samples can be prepared by electropolishing. For others such as aluminum alloy-boron composites ion erosion is necessary.When one wishes to examine a specimen with the electron beam perpendicular to the fiber, preparation is as follows: A 1/8 in. disk is cut from the sample with a cylindrical tool by spark machining. Thin slices, 5 mils thick, containing one row of fibers, are then, spark-machined from the disk. After spark machining, the slice is carefully polished with diamond paste until the row of fibers is exposed on each side, as shown in Figure 1.In the case where examination is desired with the electron beam parallel to the fiber, preparation is as follows: Experimental composites are usually 50 mils or less in thickness so an auxiliary holder is necessary during ion milling and for easy transfer to the electron microscope. This holder is pure aluminum sheet, 3 mils thick.

Direct Observation of Heat Exchanger Deposits by Cross Sectioning

1967 ◽  
Vol 25 ◽  
pp. 364-365
Author(s):  
R. W. Anderson ◽  
D. L. Senecal
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Heat Exchanger ◽  
Direct Observation ◽  
Cross Sections ◽  
Preparation Method ◽  
Specimen Preparation ◽  
Flowing Water ◽  
Transmission Electron ◽  
Deposit Layer

A problem was presented to observe the packing densities of deposits of sub-micron corrosion product particles. The deposits were 5-100 mils thick and had formed on the inside surfaces of 3/8 inch diameter Zircaloy-2 heat exchanger tubes. The particles were iron oxides deposited from flowing water and consequently were only weakly bonded. Particular care was required during handling to preserve the original formations of the deposits. The specimen preparation method described below allowed direct observation of cross sections of the deposit layers by transmission electron microscopy.The specimens were short sections of the tubes (about 3 inches long) that were carefully cut from the systems. The insides of the tube sections were first coated with a thin layer of a fluid epoxy resin by dipping. This coating served to impregnate the deposit layer as well as to protect the layer if subsequent handling were required.

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