The Electronic Structures and Formation Mechanisms of the Single-Walled BN Nanotube with Small Diameter

A nondestructive replica technique permitting complete inspection of bore surfaces having an inside diameter from 0.050 inch to 0.500 inch is described. Replicas are thermally formed on the outside surface of plastic tubing inflated in the bore of the sample being studied. This technique provides a new medium for inspection of bores that are too small or otherwise beyond the operating limits of conventional inspection methods.Bore replicas may be prepared by sliding a length of plastic tubing completely through the bore to be studied as shown in Figure 1. Polyvinyl chloride tubing suitable for this replica process is commercially available in sizes from 0.037- to 0.500-inch diameter. A tube size slightly smaller than the bore to be replicated should be used to facilitate insertion of the plastic replica blank into the bore.

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The dislocation structure of a 10° [110] tilt boundary in silicon

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100074446 ◽

1983 ◽

Vol 41 ◽

pp. 114-115

Author(s):

B. Cunningham ◽

D.G. Ast

Keyword(s):

Dislocation Structure ◽

Tilt Angle ◽

Imaging Technique ◽

Diamond Lattice ◽

Tilt Boundary ◽

Formation Mechanisms ◽

Diffraction Contrast ◽

Lattice Fringe ◽

Tilt Boundaries ◽

Chemically Vapor Deposited

There have Been a number of studies of low-angle, θ < 4°, [10] tilt boundaries in the diamond lattice. Dislocations with Burgers vectors a/2<110>, a/2<112>, a<111> and a<001> have been reported in melt-grown bicrystals of germanium, and dislocations with Burgers vectors a<001> and a/2<112> have been reported in hot-pressed bicrystals of silicon. Most of the dislocations were found to be dissociated, the dissociation widths being dependent on the tilt angle. Possible dissociation schemes and formation mechanisms for the a<001> and a<111> dislocations from the interaction of lattice dislocations have recently been given.The present study reports on the dislocation structure of a 10° [10] tilt boundary in chemically vapor deposited silicon. The dislocations in the boundary were spaced about 1-3nm apart, making them difficult to resolve by conventional diffraction contrast techniques. The dislocation structure was therefore studied by the lattice-fringe imaging technique.

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Structural Organization and Distribution of Fiber Types in Extraocular Muscles of Cats

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100093420 ◽

1972 ◽

Vol 30 ◽

pp. 34-35

Author(s):

Asish C. Nag ◽

Lee D. Peachey

Keyword(s):

Fiber Type ◽

Light And Electron Microscopy ◽

Small Diameter ◽

Extraocular Muscles ◽

Fiber Types ◽

Distinctive Features ◽

Superior Rectus ◽

Adult Cats ◽

Different Diameters ◽

Orbital Region

Cat extraocular muscles consist of two regions: orbital, and global. The orbital region contains predominantly small diameter fibers, while the global region contains a variety of fibers of different diameters. The differences in ultrastructural features among these muscle fibers indicate that the extraocular muscles of cats contain at least five structurally distinguishable types of fibers.Superior rectus muscles were studied by light and electron microscopy, mapping the distribution of each fiber type with its distinctive features. A mixture of 4% paraformaldehyde and 4% glutaraldehyde was perfused through the carotid arteries of anesthetized adult cats and applied locally to exposed superior rectus muscles during the perfusion.

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Prospects for convergent beam electron diffraction with a 200kV cold field-emission transmission electron microscope

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100086635 ◽

1991 ◽

Vol 49 ◽

pp. 466-467

Author(s):

J W Steeds ◽

R Vincent

Keyword(s):

Field Emission ◽

High Performance ◽

Small Diameter ◽

Convergent Beam Electron Diffraction ◽

Zone Axis ◽

Medium Voltage ◽

Transmission Electron ◽

Good Crystallinity ◽

Special Modification ◽

Convergent Beam

We review the analytical powers which will become more widely available as medium voltage (200-300kV) TEMs with facilities for CBED on a nanometre scale come onto the market. Of course, high performance cold field emission STEMs have now been in operation for about twenty years, but it is only in relatively few laboratories that special modification has permitted the performance of CBED experiments. Most notable amongst these pioneering projects is the work in Arizona by Cowley and Spence and, more recently, that in Cambridge by Rodenburg and McMullan.There are a large number of potential advantages of a high intensity, small diameter, focussed probe. We discuss first the advantages for probes larger than the projected unit cell of the crystal under investigation. In this situation we are able to perform CBED on local regions of good crystallinity. Zone axis patterns often contain information which is very sensitive to thickness changes as small as 5nm. In conventional CBED, with a lOnm source, it is very likely that the information will be degraded by thickness averaging within the illuminated area.

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Formation Mechanisms for Multiply Twinned Particles During Nucleation in the Au/MICA System

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100114049 ◽

1975 ◽

Vol 33 ◽

pp. 84-85

Author(s):

Eal H. Lee ◽

Helmut Poppa

Keyword(s):

Deposition Time ◽

High Vacuum ◽

Dark Field ◽

Ultra High Vacuum ◽

Formation Mechanisms ◽

Heat Treated ◽

Cluster Density ◽

Diffraction Patterns ◽

Crystal Particle ◽

Multiply Twinned Particles

The formation of thin films of gold on mica has been studied in ultra-high vacuum (5xl0-10 torr) . The mica substrates were heat-treated for 24 hours at 375°C, cleaved, and annealed for 15 minutes at the deposition temperature of 300°C prior to deposition. An impingement flux of 3x1013 atoms cm-2 sec-1 was used. These conditions were found to give high number densities of multiple twin particles and are based on a systematic series of nucleation experiments described elsewhere. Individual deposits of varying deposition time were made and examined by bright and dark field TEM after "cleavage preparation" of highly transparent specimens. In the early stages of growth, the films generally consist of small particles which are either single crystals or multiply twinned; a strong preference for multiply twinned particles was found whenever the particle number densities were high. Fig. 1 shows the stable cluster density ns and the variation with deposition time of multiple twin particle and single crystal particle densities, respectively. Corresponding micrographs and diffraction patterns are shown in Fig. 2.

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Applications of SIMS to electronic materials and devices

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100133047 ◽

1992 ◽

Vol 50 (2) ◽

pp. 1682-1683

Author(s):

S.F. Corcoran

Keyword(s):

Depth Distribution ◽

Secondary Ion Mass Spectrometry ◽

Semiconductor Device ◽

Electronic Materials ◽

Profile Analysis ◽

Semiconductor Industry ◽

Small Diameter ◽

Depth Resolution ◽

Detection Sensitivity

Over the past decade secondary ion mass spectrometry (SIMS) has played an increasingly important role in the characterization of electronic materials and devices. The ability of SIMS to provide part per million detection sensitivity for most elements while maintaining excellent depth resolution has made this technique indispensable in the semiconductor industry. Today SIMS is used extensively in the characterization of dopant profiles, thin film analysis, and trace analysis in bulk materials. The SIMS technique also lends itself to 2-D and 3-D imaging via either the use of stigmatic ion optics or small diameter primary beams.By far the most common application of SIMS is the determination of the depth distribution of dopants (B, As, P) intentionally introduced into semiconductor materials via ion implantation or epitaxial growth. Such measurements are critical since the dopant concentration and depth distribution can seriously affect the performance of a semiconductor device. In a typical depth profile analysis, keV ion sputtering is used to remove successive layers the sample.

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