scholarly journals In situAFM study of near-surface crystallization in PET and PEN

2016 ◽  
Vol 133 (48) ◽  
Author(s):  
Kei Shinotsuka ◽  
Hazel Assender
1981 ◽  
Vol 10 ◽  
Author(s):  
J. S. Williams ◽  
F. M. Adams ◽  
K. G. Rossiter

High resolution ion channelling and reflection electron diffraction techniques have been used to examine details of epitaxial regrowth in Ar+-ion-implanted GaAs(100) at furnace anneal temperatures of 400°C or less. In particular, we have investigated the nature and extent of epitaxial regrowth during both isothermal and isochronal annealing for various implant energies and for implant doses above and below the amorphous threshold. Our results indicate the development of a nonplanar growth interface during annealing which may lead, ultimately, to complex near-surface crystallization processes. Consistently with our observations and recent results from other laboratories, we propose a model for the epitaxial regrowth of amorphous GaAs layers based upon non-uniform growth rates along the amorphous-crystalline interface which could arise from local stoichiometry imbalance.


Polymer ◽  
2012 ◽  
Vol 53 (24) ◽  
pp. 5554-5559 ◽  
Author(s):  
Kei Shinotsuka ◽  
Valery N. Bliznyuk ◽  
Hazel E. Assender

2002 ◽  
Vol 304 (1-3) ◽  
pp. 25-30 ◽  
Author(s):  
Isak Avramov ◽  
Guenter Voelksch

2012 ◽  
Vol 340 ◽  
pp. 012088 ◽  
Author(s):  
S Gerth ◽  
M Klimczak ◽  
A Nelson ◽  
A Magerl

1988 ◽  
Vol 62 (01) ◽  
pp. 1-8 ◽  
Author(s):  
Ronald E. Martin

The utility of benthic foraminifera in bathymetric interpretation of clastic depositional environments is well established. In contrast, bathymetric distribution of benthic foraminifera in deep-water carbonate environments has been largely neglected. Approximately 260 species and morphotypes of benthic foraminifera were identified from 12 piston core tops and grab samples collected along two traverses 25 km apart across the northern windward margin of Little Bahama Bank at depths of 275-1,135 m. Certain species and operational taxonomic groups of benthic foraminifera correspond to major near-surface sedimentary facies of the windward margin of Little Bahama Bank and serve as reliable depth indicators. Globocassidulina subglobosa, Cibicides rugosus, and Cibicides wuellerstorfi are all reliable depth indicators, being most abundant at depths >1,000 m, and are found in lower slope periplatform aprons, which are primarily comprised of sediment gravity flows. Reef-dwelling peneroplids and soritids (suborder Miliolina) and rotaliines (suborder Rotaliina) are most abundant at depths <300 m, reflecting downslope bottom transport in proximity to bank-margin reefs. Small miliolines, rosalinids, and discorbids are abundant in periplatform ooze at depths <300 m and are winnowed from the carbonate platform. Increased variation in assemblage diversity below 900 m reflects mixing of shallow- and deep-water species by sediment gravity flows.


Author(s):  
P.M. Rice ◽  
MJ. Kim ◽  
R.W. Carpenter

Extrinsic gettering of Cu on near-surface dislocations in Si has been the topic of recent investigation. It was shown that the Cu precipitated hetergeneously on dislocations as Cu silicide along with voids, and also with a secondary planar precipitate of unknown composition. Here we report the results of investigations of the sense of the strain fields about the large (~100 nm) silicide precipitates, and further analysis of the small (~10-20 nm) planar precipitates.Numerous dark field images were analyzed in accordance with Ashby and Brown's criteria for determining the sense of the strain fields about precipitates. While the situation is complicated by the presence of dislocations and secondary precipitates, micrographs like those shown in Fig. 1(a) and 1(b) tend to show anomalously wide strain fields with the dark side on the side of negative g, indicating the strain fields about the silicide precipitates are vacancy in nature. This is in conflict with information reported on the η'' phase (the Cu silicide phase presumed to precipitate within the bulk) whose interstitial strain field is considered responsible for the interstitial Si atoms which cause the bounding dislocation to expand during star colony growth.


Author(s):  
Naresh N. Thadhani ◽  
Thad Vreeland ◽  
Thomas J. Ahrens

A spherically-shaped, microcrystalline Ni-Ti alloy powder having fairly nonhomogeneous particle size distribution and chemical composition was consolidated with shock input energy of 316 kJ/kg. In the process of consolidation, shock energy is preferentially input at particle surfaces, resulting in melting of near-surface material and interparticle welding. The Ni-Ti powder particles were 2-60 μm in diameter (Fig. 1). About 30-40% of the powder particles were Ni-65wt% and balance were Ni-45wt%Ti (estimated by EMPA).Upon shock compaction, the two phase Ni-Ti powder particles were bonded together by the interparticle melt which rapidly solidified, usually to amorphous material. Fig. 2 is an optical micrograph (in plane of shock) of the consolidated Ni-Ti alloy powder, showing the particles with different etching contrast.


Author(s):  
R.C. Dickenson ◽  
K.R. Lawless

In thermal oxidation studies, the structure of the oxide-metal interface and the near-surface region is of great importance. A technique has been developed for constructing cross-sectional samples of oxidized aluminum alloys, which reveal these regions. The specimen preparation procedure is as follows: An ultra-sonic drill is used to cut a 3mm diameter disc from a 1.0mm thick sheet of the material. The disc is mounted on a brass block with low-melting wax, and a 1.0mm hole is drilled in the disc using a #60 drill bit. The drill is positioned so that the edge of the hole is tangent to the center of the disc (Fig. 1) . The disc is removed from the mount and cleaned with acetone to remove any traces of wax. To remove the cold-worked layer from the surface of the hole, the disc is placed in a standard sample holder for a Tenupol electropolisher so that the hole is in the center of the area to be polished.


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