Observation of dislocation reactions in CDTE at lattice resolution

1983 ◽  
Vol 41 ◽  
pp. 112-113
Author(s):  
T. Yamashita ◽  
R. Sinclair
Keyword(s):  
Partial Dislocation ◽  
Video Recording ◽  
Dislocation Motion ◽  
Video Tape ◽  
Exposure Rate ◽  
Shockley Partial Dislocation ◽  
Shockley Partial ◽  
Partial Dislocations ◽  
Lattice Resolution ◽  
Obvious Extension

Recently, lattice resolution video-recording of dislocation motion in CdTe has been reported by Sinclair et al, using the Cambridge 500 keV microscope equipped with a TV camera. Phenomena such as the motion of Shockley partial dislocations and climb of Frank dislocations were recorded onto a video tape which has an exposure rate of 50 half-frames per second. An obvious extension of this work is to study the dislocation reactions. An example of such a reaction which was detected in CdTe is shown in Fig. 1. The micrographs were taken several seconds apart in a JEOL 200CX microscope, and they show dissociation of a Frank dislocation into a Shockley partial dislocation and a Lomer dislocation (ie., a sessile lock).

Transformation–dislocation dipoles in Laves phases: A high-resolution transmission electron microscopy analysis

2010 ◽  
Vol 25 (10) ◽  
pp. 1983-1991 ◽  
Author(s):  
J. Aufrecht ◽  
A. Leineweber ◽  
V. Duppel ◽  
E.J. Mittemeijer
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
High Resolution ◽  
Partial Dislocation ◽  
Laves Phases ◽  
Dislocation Configuration ◽  
Shockley Partial Dislocation ◽  
Shockley Partial ◽  
Partial Dislocations ◽  
Transmission Electron

Images of synchro-Shockley partial dislocation arrangements in the Laves phases NbCr2 and HfCr2 have been obtained by high-resolution transmission electron microscopy. The analysis of the stacking sequences around these arrangements revealed the role of the constituting partial dislocations in enabling the polytypic C14 → C36/6H phase transformation in both alloys. The synchro-Shockley partial dislocations occur in and move through the crystals mainly as dipoles of partials of opposite signs, leading to—as compared to isolated partials—strain fields of lesser extent. In NbCr2 a single, probably quenched synchro-Shockley partial dislocation dipole, consisting of two partials with Burgers vectors of opposite sign, was identified. The ordered passage of a series of this type of line defects brings about the C14 → C36 transformation. In HfCr2 a complex synchro-Shockley partial dislocation configuration was revealed. It can be regarded as an “antiphase boundary” between two C36 domains. It is likely that this defect structure had formed by impingement of two domains of C36 growing perpendicular to the stacking direction by glide of synchro-Shockley partial dislocation dipoles.

scholarly journals Shrinking stacking fault through glide of the Shockley partial dislocation in hard-sphere crystal under gravity

2007 ◽  
Vol 105 (10) ◽  
pp. 1377-1383 ◽  
Author(s):  
Atsushi Mori ◽  
Yoshihisa Suzuki ◽  
Shin-Ichiro Yanagiya ◽  
Tsutomu Sawada ◽  
Kensaku Ito
Keyword(s):  
Hard Sphere ◽  
Partial Dislocation ◽  
Stacking Fault ◽  
Shockley Partial Dislocation ◽  
Shockley Partial

Shockley Partial Dislocation-Induced Self-Rectified 1D Hydrogen Evolution Photocatalyst

2019 ◽  
Vol 11 (22) ◽  
pp. 20521-20527 ◽  
Author(s):  
Zhonghui Han ◽  
Weizhao Hong ◽  
Weinan Xing ◽  
Yidong Hu ◽  
Yansong Zhou ◽  
...  
Keyword(s):  
Hydrogen Evolution ◽  
Partial Dislocation ◽  
Shockley Partial Dislocation ◽  
Shockley Partial

Effect of Ta on the Structure and Dynamics of γ/α2 Interfaces in Tial

1990 ◽  
Vol 213 ◽  
Author(s):  
S. R. Singh ◽  
J. M. Howe
Keyword(s):  
Partial Dislocation ◽  
Growth Mechanisms ◽  
Tial Alloys ◽  
Shockley Partial ◽  
Structure And Dynamics ◽  
Partial Dislocations ◽  
Α2 Phase ◽  
Atomically Flat ◽  
Ledge Mechanism ◽  
Image Simulations

ABSTRACTThe structure of γ/α interfaces in binary and Ta-containing TiAl alloys were analyzed by HRTEM and image simulations. Growth of α2 was found to be due to a ledge mechanism, consisting of Shockley partial dislocations on alternate (111)γ planes. The interface is atomically flat between the ledges and addition of Ta was found to transform arrays of growth ledges in the binary alloy into islands on the plate faces in the Ta-containing alloy. These islands of α2 on the γ/α2 interfaces were 4–7nm wide and increased in size with decreasing ageing temperature. The height of the ledges and islands were always a multiple of the c-parameter (0.46nm) of the α2 phase. The islands were bounded by 90°(edge) and 30° screw) Shockley partial dislocations. The 30° partial dislocation cores were localized whereas the 90° partial dislocation cores appeared to be highly delocalized due to presence of a high density of kinks, which in one case was found to be about 0.65nm−1.These results are interpreted in terms of the growth mechanisms and morphology of the α2 phase.

Densification Behavior in Spark-Plasma-Sintering of MgAl2O4 Spinel

2010 ◽  
Vol 654-656 ◽  
pp. 1986-1989
Author(s):  
Koji Morita ◽  
Byung Nam Kim ◽  
Hidehiro Yoshida ◽  
Keijiro Hiraga
Keyword(s):  
Effective Stress ◽  
Partial Dislocation ◽  
Stacking Faults ◽  
Dislocation Motion ◽  
Densification Rate ◽  
Densification Mechanism ◽  
Partial Dislocations ◽  
Plasma Sintering ◽  
Rate Relationship ◽  
Spark Plasma

The densification mechanism in park-plasma-sintering (SPS) processing was examined in MgAl2O4 spinel. As the relative density ρt increases, that is, as the effective stress σeff decreases, stress exponent n evaluated from effective stress-densification rate relationship continuously varies from n  4 to n  1. TEM observation shows that significant stacking faults caused by partial dislocations are frequently observed in the low ρt region. The results suggest that, for spinel, the predominant densification mechanism in SPS processing changes with ρt from plastic flow by a partial dislocation motion in the low ρt region (n  4) to diffusion-related creep in the high ρt region (n  1).

The study of defects in Sb2S3 by method of direct lattice resolution

1978 ◽  
Vol 36 (1) ◽  
pp. 312-313
Author(s):  
V.M. Kosevich ◽  
A.A. Sokol ◽  
A.G. Bagmut
Keyword(s):  
Defect Structure ◽  
Partial Dislocation ◽  
Stacking Faults ◽  
Substrate Plane ◽  
Partial Dislocations ◽  
Displacement Vectors ◽  
Initial Stage ◽  
Direct Lattice ◽  
Lattice Resolution ◽  
Deposited Films

1.Sb2S3 has the orthorombic lattice with a=11,23;b=11,31; c=3,84 Å. Its crystal structure is constructed of the double ribbons of antimony and sulphur atoms,parallel to [00l].Vacuum deposited films of Sb2S3 re amorphous{they were crystallyzed in spherolite mode by the electronbeam heating.The study of defect structure of the Sb2S3 spherolite crystals by method of direct lattice resolution was the aim of present work.The images of (100),(200),(010),(020),(110) and (110) planes were obtained.2.Several types of the ribbons stacking faults were obserwed in Sb2S3 crystals with (001) parallel to the substrate plane (Fig.1).The stac-kingfault planes and their displacement vectors R are the following: a) (010),(110),R=1/2 [010];b) (100),R=1/2 [210],R=1/4[210].3.There were obtained the images of partial dislocations with b=1/2 [010] and small-andle boundaries,consisted of the dissociated partial dislocation pairs,in Sb2s3 crystals with (100) and (010) planes parallel to the substrate.Small-angle boundaries appeared on initial stage of the spherolite growth,when splitting of spherolite single-crystal nucleus was taking place (Fig.2).

Synchrotron Topography Studies of Growth and Deformation-Induced Dislocations in 4H-SiC

2012 ◽  
Vol 1433 ◽  
Author(s):  
M. Dudley ◽  
H. Wang ◽  
F. Wu ◽  
S. Byrappa ◽  
S. Shun ◽  
...  
Keyword(s):  
Crystal Growth ◽  
Single Crystals ◽  
Basal Plane ◽  
Partial Dislocation ◽  
Reversible Process ◽  
Burgers Vector ◽  
Shockley Partial ◽  
Partial Dislocations ◽  
Equilibrium Concentrations ◽  
Dislocation Multiplication

ABSTRACTSynchrotron topography studies are presented of the behavior of growth dislocations and deformation-induced dislocations in 4H-SiC single crystals. The growth dislocations include those in threading orientation with line directions approximately along c with Burgers vectors of a, c, and na+mc (where n and m are integers) while the deformation-induced dislocations include those with line directions confined to the basal plane with Burgers vectors of a and Shockley partial dislocations with Burgers vectors of 1/3<1-100> as well as those with line directions in the {1-100} prismatic planes with Burgers vectors of a. Processes leading to the nucleation of the growth dislocations are discussed as well as their deflection onto the basal plane during crystal growth in a reversible process. This latter process can lead to the conversion of segments of the deflected growth dislocations into deformation induced dislocations. In some cases this can lead to dislocation multiplication via the Hopping Frank-Read source mechanism and in others to the motion of single Shockley partial dislocations leading to Shockley stacking fault expansion. Studies are also presented of interactions between threading growth dislocations with c-component of Burger’s vector facilitated by climb processes which are mediated by interactions with non-equilibrium concentrations of vacancies. This can lead to reactions whereby complete or partial dislocation Burgers vector annihilation occurs.

Computer Simulation of Creation of Dislocations in Copper Small Crystals

1993 ◽  
Vol 319 ◽  
Author(s):  
H. Tanaka ◽  
Masao Doyama
Keyword(s):  
Molecular Dynamics ◽  
Computer Simulation ◽  
Partial Dislocation ◽  
Stacking Fault ◽  
Shockley Partial Dislocation ◽  
Shockley Partial ◽  
Small Crystals ◽  
The Creation

AbstractDislocations were created near the center of the surface (101) of copper small crystals whose surfaces are (111), (111), (101), (101), (121), and (121) by use of n-body atom potentials and molecular dynamics. At first, a Heidenreich-Shockley partial dislocation was created., As the partial dislocation proceeds, the partial dislocation and the surface was connected with a stacking fault until the next Heidenreich-Shockley partial dislocation was created at the surface.Just before the creation of a partial dislocation the stress was the highest.

Creation of Dislocations in a Shall Copper Single Crystal

1992 ◽  
Vol 278 ◽  
Author(s):  
Masao Doyama
Keyword(s):  
Single Crystal ◽  
Yield Stress ◽  
Partial Dislocation ◽  
Stacking Fault ◽  
Copper Single Crystal ◽  
Shockley Partial ◽  
Partial Dislocations ◽  
Edge Dislocations

AbstractEdge dislocations were created on a surface of a small copper single crystal. Very sharp yield stress was observed when a partial dislocation was created. Edge dislocations in copper were split into Heidenreich–Shockley partial dislocations connected with the stacking fault.

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