From δl- to δTc-pinning in CaKFe4As4 single crystals obtained by adjusting their defect structures

2021 ◽  
Author(s):  
Chunlei Wang ◽  
Tian He ◽  
Dong Chen ◽  
Jingyi Zhang ◽  
Chunfeng Fan ◽  
...  
Keyword(s):  
Single Crystals ◽  
Defect Structures

Characterization of Defect Structures in 3C-SiC Single Crystals Using Synchrotron White Beam X-ray Topography

1996 ◽  
Vol 423 ◽  
Author(s):  
W. Huang ◽  
M. Dudley ◽  
C. Fazi
Keyword(s):  
Single Crystals ◽  
Stacking Faults ◽  
Interference Microscopy ◽  
Defect Structures ◽  
Growth Sector ◽  
X Ray ◽  
Partial Dislocations ◽  
White Beam ◽  
Transmission And Reflection

AbstractDefect structures in (111) 3C-SiC single crystals, grown using the Baikov technique, have been studied using Synchrotron White Beam X-ray Topography (SWBXT). The major types of defects include complex growth sector boundary structures, double positioning twins, stacking faults on { 111 } planes, inclusions and dislocations (including growth dislocations and partial dislocations bounding stacking faults). Detailed stacking fault and double positioning twin configurations are determined using a combination of Nomarski interference microscopy, SEM and white beam x-ray topography in both transmission and reflection geometries. Possible defect generation phenomena are discussed.

Characterization of Defect Structures in SiC Single Crystals Using Synchrotron X-Ray Topography

1993 ◽  
Vol 307 ◽  
Author(s):  
S. Wang ◽  
M. Dudley ◽  
C. Carter ◽  
D. Asbury ◽  
C. Fazit
Keyword(s):  
Detailed Analysis ◽  
Single Crystals ◽  
Basal Plane ◽  
Defect Structures ◽  
Dislocation Generation ◽  
Screw Dislocations ◽  
X Ray ◽  
White Beam

ABSTRACTSynchrotron white beam X-ray topography has been used to characterize defect structures in 6H-SiC wafers grown on (0001) seeds. Two major types of defects are observed: super screw dislocations approximately perpendicular to the basal plane and dislocation networks lying in the basal plane. The super screw dislocations, which have open cores, are growth dislocations. These dislocations act as sources and/or sinks for the glide dislocation networks. Detailed analysis and discussion of dislocation generation phenomena and Burgers vectors will be presented.

Synchrotron X-Ray Topographic Study of Defects in High Quality, Flux Grown Ktiopo4 Single Crystals

1993 ◽  
Vol 307 ◽  
Author(s):  
S. Wang ◽  
M. Dudley ◽  
L. K. Cheng ◽  
J. D. Bierlein
Keyword(s):  
Detailed Analysis ◽  
Single Crystals ◽  
Domain Walls ◽  
Defect Structures ◽  
Growth Sector ◽  
High Quality ◽  
X Ray ◽  
Free Region ◽  
Ferroelectric Domains ◽  
Section Topography

ABSTRACTDefect structures in large, high quality flux-grown KTP single crystals have been studied by using synchrotron white beam X-ray topography. Growth dislocations, inclusions, growth sector boundaries, growth bands and surface micro-scratches were imaged. A number of planar defects in the dislocation-free region are imaged and determined to be inversion twin lamellae (lamellar ferroelectric domains) which have never been previously reported in KTP crystals. These inversion twin lamellae were also studied by section topography. Detailed analysis of observed contrast revealed that the domain walls bounding the lamellae are faulted with a fault vector of ½[0±1±1]. This fault vector seems to be consistent with the atomic structure of KTP. A detailed analysis is presented and discussed.

Laser Irradiation of Nickel: Defect Structures and Surface Alloying

1980 ◽  
Vol 1 ◽  
Author(s):  
L. Buene ◽  
D.C. Jacobson ◽  
S. Nakahara ◽  
J.M. Poate ◽  
C.W. Draper ◽  
...  
Keyword(s):  
Laser Radiation ◽  
Dislocation Density ◽  
Single Crystals ◽  
Cell Structure ◽  
Dislocation Cell ◽  
Dislocation Network ◽  
Defect Structures ◽  
Surface Alloying ◽  
Surface Layers ◽  
Laser Melting

ABSTRACTSurface layers of Ni crystals have been melted with Q-switched Nd-YAG laser radiation. The epitaxially regrown surface layers show significant differences between 〈100〉 and 〈111〉 crystals cut from the same boule. The 〈100〉 crystals exhibit a dislocation cell structure with a dislocation density of l011 - 1012 cm-2. The 〈111〉 crystals contain a laterally uniform dislocation network resulting in a much higher dislocation density for the 〈111〉 surface. The elements Ag, Au, Pd, Sn and Ta have been implanted into Ni single crystals at surface concentrations of up to 20 at %. All the as- implanted systems demonstrate solid solubility. We have used these implanted systems to study the alloys formed by laser melting of Ni. In all systems, with the exception of Ag, 100% of the atoms are trapped on lattice sites.

Study of Defect Structures in BeO Single Crystals by X‐Ray Diffraction Topography

1965 ◽  
Vol 36 (12) ◽  
pp. 3815-3822 ◽  
Author(s):  
S. B. Austerman ◽  
J. B. Newkirk ◽  
D. K. Smith
Keyword(s):  
Single Crystals ◽  
Defect Structures ◽  
X Ray Diffraction ◽  
X Ray

Spectroscopy of discrete vertically oriented single-crystals of n-type tetraazaterrylene: understanding the role of defects in molecular semiconductor photovoltaics

2014 ◽  
Vol 16 (30) ◽  
pp. 15825-15830 ◽  
Author(s):  
A. J. Wise ◽  
Y. Zhang ◽  
J. Fan ◽  
F. Wudl ◽  
A. L. Briseno ◽  
...  
Keyword(s):  
Single Crystals ◽  
Defect Structures ◽  
Molecular Semiconductor

Oriented single crystals of tetra-aza-terrylene (TAT), and photoluminescence of pristine and defect structures.

Characterization of defect structures in magnetic liquid encapsulated Kyropoulos grown InP single crystals

1997 ◽  
Vol 181 (1-2) ◽  
pp. 17-25 ◽  
Author(s):  
H. Chung ◽  
W. Si ◽  
M. Dudley ◽  
D.F. Bliss ◽  
R. Kalan ◽  
...  
Keyword(s):  
Single Crystals ◽  
Defect Structures ◽  
Magnetic Liquid

Defect structures of VB2 and NbB2 single crystals

1981 ◽  
Vol 82 ◽  
pp. 309-316 ◽  
Author(s):  
K. Nakano ◽  
M. Doi ◽  
K. Kuwayama ◽  
T. Imura
Keyword(s):  
Single Crystals ◽  
Defect Structures

Characterization of Defect Structures in Lely 6H-SiC Single Crystals Using Synchrotron White Beam X-Ray Topography

1994 ◽  
Vol 375 ◽  
Author(s):  
W. Huang ◽  
S. Wang ◽  
M. Dudley ◽  
P. Neudeck ◽  
J. A. Powell ◽  
...  
Keyword(s):  
Single Crystals ◽  
Basal Plane ◽  
Stacking Faults ◽  
Defect Structures ◽  
Dislocation Generation ◽  
X Ray ◽  
Partial Dislocations ◽  
White Beam ◽  
Generation Mechanisms

AbstractDefect structures in Lely SiC single crystals have been studied using synchrotron white beam X-ray topography. Basal plane dislocations and stacking faults probably generated during post-growth cooling are clearly revealed. For both perfect dislocations and partial dislocations bounding the stacking faults, Burgers vectors and line directions are determined from contrast extinction analysis as well as projected direction analysis on different topographic images. The fault planes and fault vectors of the stacking faults were determined using contrast extinction analysis. Possible dislocation generation mechanisms are briefly discussed.

Sign in / Sign up

Export Citation Format

Share Document