The electric properties of eclogites from the Bohemian Massif under high temperatures and pressures

1976 ◽  
Vol 114 (3) ◽  
pp. 451-460 ◽  
Author(s):  
M. Laštovičková ◽  
E. I. Parchomenko
Keyword(s):  
High Temperatures ◽  
Bohemian Massif ◽  
Electric Properties

Immobilization Phenomenon of Partials Surrounding Double Shockley Stacking Faults in Heavily Nitrogen Doped 4H-SiC Crystal with Thermal Anneal

2018 ◽  
Vol 924 ◽  
pp. 160-163 ◽  
Author(s):  
Naohiro Sugiyama ◽  
Hiromasa Suo ◽  
Kazuma Eto ◽  
Yuichiro Tokuda ◽  
Isaho Kamata ◽  
...  
Keyword(s):  
High Temperature ◽  
Thermal Annealing ◽  
High Temperatures ◽  
Stacking Faults ◽  
Electric Properties ◽  
High Temperature Annealing ◽  
Nitrogen Doped ◽  
Low Resistance ◽  
Partial Dislocations ◽  
Expansion Behavior

The expansion behavior of double Shockley stacking faults (DSFs) was investigated in heavily nitrogen doped 4H-SiC crystals at high temperatures up to 1350°C. An immobilization phenomenon of partials surrounding DSFs was discovered by a thermal annealing at temperatures over 1275°C. The electric properties of SiC crystal were maintained after the partial dislocations were immobilized with a high temperature annealing. The mobile partial dislocations extended straight, but the immobile ones bent toward the glide direction. This immobilization phenomenon is significant and useful for achieving low-resistance SiC substrates without DSFs.

XV.—On the Thermo-Electric Properties of Charcoal and certain Alloys, with a Supplementary Thermo-Electric Diagram

1878 ◽  
Vol 28 (2) ◽  
pp. 321-343 ◽  
Author(s):  
C. G. Knott ◽  
J. G. MacGregor
Keyword(s):  
High Temperatures ◽  
Copper Wire ◽  
Electric Properties ◽  
Thin Wire ◽  
Thermo Electric ◽  
First Approximation ◽  
The Wire ◽  
Almost All

The determination by experiment of the thermo-electric relations of any one substance belonging to the electromotive series to all other such substances is sufficient to fix all mutual thermo-electric relations among these. The first endeavour of the experimenter is then to obtain as convenient a substance for this purpose as possible. In investigating charcoal and certain alloys, we have in almost all cases employed one or other of two alloys of platinum and iridium, which have been already used by Professor Tait for a like purpose. The wires we used were the same which he discusses in his “First Approximation to a Thermo-Electric Diagram,” under the names of M and N. Their complete freedom from oxidation, their elasticity, and the high temperatures of their fusing points, rendered them peculiarly suitable for thermo-electric investigations through long ranges of temperature.Generally both the M and N wires were firmly bound, each by its one extremity to the end or ends of the wire or wires respectively which were under investigation, in a multiple junction. This triple or, as it was in some cases, quadruple junction constituted the “hot junction.” The free extremities of the wires thus united were each bound to a moderately thin copper wire by very thin wire of the same metal, and the copper wires were led from these “cold junctions” to a commutator, which was in connection with a galvanometer. The commutator consisted of an arrangement of small mercury pools, into which the galvanometer and circuit wires, carefully amalgamated to ensure contact, dipped. All the junctions were formed in the manner indicated above, namely, by tightly binding the extremities of the wires together by thin copper wire.

Thermal and electric conductivity of three basaltic rocks of the Bohemian Massif under high temperatures

1982 ◽  
Vol 26 (1) ◽  
pp. 93-95 ◽  
Author(s):  
Z. V. Chanishvilli ◽  
Marcela Laštovičkova ◽  
Vladimír Kropáček ◽  
A. Janáčková
Keyword(s):  
Electric Conductivity ◽  
High Temperatures ◽  
Bohemian Massif ◽  
Basaltic Rocks

In situ REM imaging of surface processes on ceramic bulk crystals from 300 to 1670 K in a conventional TEM

1991 ◽  
Vol 49 ◽  
pp. 660-661
Author(s):  
Z. L. Wang ◽  
J. Bentley
Keyword(s):  
High Temperatures ◽  
Image Resolution ◽  
Atomic Processes ◽  
Crystal Surfaces ◽  
Beam Radiation ◽  
Surface Areas ◽  
Transmission Electron ◽  
Reflection Electron Microscopy ◽  
Gas Reactions

Studying the behavior of surfaces at high temperatures is of great importance for understanding the properties of ceramics and associated surface-gas reactions. Atomic processes occurring on bulk crystal surfaces at high temperatures can be recorded by reflection electron microscopy (REM) in a conventional transmission electron microscope (TEM) with relatively high resolution, because REM is especially sensitive to atomic-height steps.Improved REM image resolution with a FEG: Cleaved surfaces of a-alumina (012) exhibit atomic flatness with steps of height about 5 Å, determined by reference to a screw (or near screw) dislocation with a presumed Burgers vector of b = (1/3)<012> (see Fig. 1). Steps of heights less than about 0.8 Å can be clearly resolved only with a field emission gun (FEG) (Fig. 2). The small steps are formed by the surface oscillating between the closely packed O and Al stacking layers. The bands of dark contrast (Fig. 2b) are the result of beam radiation damage to surface areas initially terminated with O ions.

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