ON THE ROLE OF STACKING FAULTS IN SOME PROBLEMS OF GLIDE AND TWINNING IN CUBIC METALS

1967 ◽  
Vol 45 (2) ◽  
pp. 481-492 ◽  
Author(s):  
B. Escaig ◽  
G. Fontaine ◽  
J. Friedel
Keyword(s):  
Point Defects ◽  
Stacking Faults ◽  
Stacking Fault ◽  
Dislocation Network ◽  
Thermal Variation ◽  
Temperature Dependent ◽  
Cubic Metals ◽  
Thermally Activated ◽  
Stacking Fault Energies

The possible role of stacking faults is discussed in some problems of glide and twinning of cubic metals, especially at low temperatures.The first part analyzes a model for the thermal variation of macroyield in b.c.c. metals. If one assumes that the dislocations of such metals split along either the (110) or the (112) planes, the screw dislocations will be sessile. The strong temperature variation of macroyield could be due to the thermally activated slip of such screws, previously developed at lower stresses during the less temperature-dependent microyield. Reasonably high stacking-fault energies are required for satisfactory numerical fits.The second part studies the influence of a dense dislocation network on the propagation of a stacking fault. The friction force acting on the partial that propagates the fault must be taken into account when deducing a stacking-fault energy from the stress at which stacking faults develop in a strongly work-hardened (f.c.c.) metal. The trails of dipoles left at each tree crossed should prevent any creation of point defects; they should lead, after the faults have propagated some length, to its multiplication into a twin or martensitic lamella. The analogies with problems of slip bauds and dipole formation in easy glide are stressed.

Temperature Dependent Stability of Stacking Fault in Highly Nitrogen-Doped 4H-SiC Crystals

2016 ◽  
Vol 858 ◽  
pp. 109-112
Author(s):  
Chisato Taniguchi ◽  
Aiko Ichimura ◽  
Noboru Ohtani ◽  
Masakazu Katsuno ◽  
Tatsuo Fujimoto ◽  
...  
Keyword(s):  
Theoretical Model ◽  
Quantum Well ◽  
Double Layer ◽  
Basal Plane ◽  
Stacking Faults ◽  
Stacking Fault ◽  
Carrier Distribution ◽  
Temperature Dependent ◽  
Nitrogen Doped ◽  
Proposed Model

The formation of basal plane stacking faults in highly nitrogen-doped 4H-SiC crystals was theoretically investigated. A novel theoretical model based on the so-called quantum well action (QWA) mechanism was proposed; the model considers several factors, which were overlooked in a previously proposed model, and explains well the annealing-induced formation of double layer Shockley-type stacking faults in highly nitrogen-doped 4H-SiC crystals. We further revised the model to consider the carrier distribution in the depletion regions adjacent to the stacking fault and were successful in explaining the shrinkage of stacking faults during annealing at even higher temperatures.

Behavior Of Point Defects In CZ Silicon Crystal Growth-Formation Of Polyhedral Cavities And Oxidation-Induced Stacking Fault Nuclei

1996 ◽  
Vol 442 ◽  
Author(s):  
K Tanahashi ◽  
N. Inoue ◽  
Y. Mizokawa
Keyword(s):  
Crystal Growth ◽  
Ternary System ◽  
Point Defects ◽  
Silicon Crystal ◽  
Stacking Faults ◽  
Stacking Fault ◽  
Czochralski Silicon ◽  
Growth Formation

AbstractThe origin of oxidation–induced stacking faults (OSF) and polyhedral cavities in as–grown Czochralski silicon (CZ–Si) crystals is discussed with comparison to the behavior of previously investigated grown–in oxide precipitates. The incorporation, diffusion and reaction in the vacancy, self–interstitial and oxygen ternary system are considered to discuss the origin of grown–in defects.

Stacking-Fault Energies in Silicon, Diamond, and Silicon Carbide

1988 ◽  
Vol 141 ◽  
Author(s):  
P. J. H. Denteneer
Keyword(s):  
Silicon Carbide ◽  
Density Functional ◽  
Density Functional Method ◽  
Stacking Faults ◽  
Functional Method ◽  
Negative Energy ◽  
Perfect Crystal ◽  
Stacking Fault ◽  
Theoretical Approaches ◽  
Stacking Fault Energies

AbstractStacking faults in a perfect crystal can be seen as limiting structures of certain series of polytypes of that crystal. A parametrization of the energy of polytypes in terms of interaction constants between layers therefore allows for the calculation of stacking-fault energies. The first-principles pseudopotential-density-functional method is used to calculate total energies of a few simple polytypes of silicon and carbon. The energies of intrinsic and extrinsic stacking faults (γISF and γESF , respectively) in silicon and diamond that follow from these calculations are in much better agreement with available experimental numbers than in previous theoretical approaches. I find: γISF = 47 mJm-2 and γESF = 36 mJm-2 for Si, γISF = 300 mJm-2 and γESF = 253 mJm-2 for diamond. From recently published similar calculations for polytypes of silicon carbide one obtains a negative energy for the extrinsic stacking fault, if zincblende silicon carbide is taken as the unfaulted structure, suggesting the observed occurrence in nature of polytypism in silicon carbide.

The role of structural imperfections in the photodimerization of 9-cyanoanthracene

1971 ◽  
Vol 324 (1559) ◽  
pp. 459-468 ◽  
Keyword(s):  
Fluorescence Microscopy ◽  
Excitation Energy ◽  
Slip Plane ◽  
Stacking Faults ◽  
Stacking Fault ◽  
Burgers Vector ◽  
Partial Dislocations ◽  
Structural Imperfections ◽  
Active Slip

Crystalline 9-cyanoanthracene undergoes photodimerization to give the trans dimer which is unexpected on the basis of the topochemical preformation theory. The possibility that the reaction occurs at defects is investigated; and the nature of the structural imperfections are described, as are also the types of product nuclei and their modes of growth. Interference-contrast and fluorescence microscopy have been employed for the examination of cleaved and partially dimerized faces of the monomer. It is shown that there is an active slip plane (221), and consideration of feasible dislocation reactions, particularly those involving unit strength dislocations which have a component of the Burgers vector in [100], reveals that, within stacking-fault regions (bounded by partial dislocations), the monomer molecules are in trans registry. It is suggested that molecules in such stacking faults act as traps for the excitation energy, and that reaction occurs at these sites.

The calculation of stacking fault energies in close-packed metals

1990 ◽  
Vol 5 (10) ◽  
pp. 2107-2119 ◽  
Author(s):  
S. Crampin ◽  
K. Hampel ◽  
D. D. Vvedensky ◽  
J. M. MacLaren
Keyword(s):  
Stacking Fault ◽  
Face Centered Cubic ◽  
Electron Theory ◽  
Simple Scheme ◽  
Cubic Metals ◽  
Interface Unit ◽  
Face Centered ◽  
Experimental Values ◽  
The One ◽  
Stacking Fault Energies

The one-electron theory of metals is applied to the calculation of stacking fault energies in face-centered cubic metals. The extreme difficulties in calculating fault energies of the order of 0.01 eV/(interface unit-cell area) are overcome by applying the Force theorem and using the layer–Korringer–Kohn–Rostoker method to determine the charge density of isolated defects. A simple scheme is presented for accommodating deviations from charge neutrality inherent in this approach. The agreement between theoretical and experimental values for the stacking fault energy is generally good, with contributions localized to within three atomic planes of the fault, but suggest the quoted value for Rh is a significant overestimation.

Stacking Fault Energies in TiCx

1996 ◽  
Vol 458 ◽  
Author(s):  
R. M. Harris ◽  
P. D. Bristowe
Keyword(s):  
Tight Binding ◽  
Stacking Faults ◽  
Stacking Fault ◽  
Tight Binding Model ◽  
Binding Model ◽  
Preliminary Results ◽  
Surface Energies ◽  
Dislocation Dissociation ◽  
Stable Stacking Faults ◽  
Stacking Fault Energies

ABSTRACTWe have used a Tight Binding model to calculate the surface energies of various (111) stacking faults in TiC1.0 and TiC0.5. Based upon our preliminary results we have identified the stable stacking faults and have examined possible dislocation dissociation reactions.

The measurement of stacking-fault energies of pure face-centred cubic metals

1971 ◽  
Vol 24 (192) ◽  
pp. 1383-1392 ◽  
Author(s):  
D. J. H. Cockayne ◽  
M. L. Jenkins ◽  
I. L. F. Ray
Keyword(s):  
Stacking Fault ◽  
Cubic Metals ◽  
Stacking Fault Energies
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