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

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.

1996 ◽  
Vol 423 ◽  
Author(s):  
W. Huang ◽  
M. Dudley ◽  
C. Fazi

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.


1993 ◽  
Vol 307 ◽  
Author(s):  
S. Wang ◽  
M. Dudley ◽  
C. Carter ◽  
D. Asbury ◽  
C. Fazit

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.


2014 ◽  
Vol 1698 ◽  
Author(s):  
Jianqiu Guo ◽  
Balaji Raghothamachar ◽  
Michael Dudley ◽  
Joan J. Carvajal ◽  
Ali Butt ◽  
...  

ABSTRACTDefect structures in Rubidium Titanyl Phosphate (RTP) crystals (non-doped and doped) grown by the Top Seeded Solution Growth (TSSG) method were characterized using Synchrotron White Beam X-ray Topography. Main defects observed in non-doped crystals are growth sector boundaries while both growth sector boundaries and growth striations are observed in the Nb single doped and (Nb,Yb)-codoped crystals with relatively few linear defects such as dislocations. Results show that the overall crystalline quality is lowered as more doping elements are incorporated. Details of defect distributions are correlated with the growth process to facilitate high quality growth of doped RTP.


2005 ◽  
Vol 38 (6) ◽  
pp. 1012-1019 ◽  
Author(s):  
M. González-Mañas ◽  
B. Vallejo ◽  
M. A. Caballero

A complex pattern of opposite and antiparallel periodic poled domains in LiNbO3single crystals has been studied by X-ray topography. The antiparallel periodic poled domains appear directly at the growth interface during the growth in alternating crescent-shaped (CS) domains. The measured Li/Nb ratio is higher in the CS domains than in other zones. A model of the electric fields responsible for the observed configuration is proposed, connected to the role of the Li atom. Diffraction contrast associated with the different domain walls is examined and different kinds of dislocations associated with the ferroelectric domains are also studied, determining their geometrical characters.


2006 ◽  
Vol 13 (6) ◽  
pp. 484-488 ◽  
Author(s):  
Taihei Mukaide ◽  
Kentaro Kajiwara ◽  
Takashi Noma ◽  
Kazuhiro Takada

1965 ◽  
Vol 36 (12) ◽  
pp. 3815-3822 ◽  
Author(s):  
S. B. Austerman ◽  
J. B. Newkirk ◽  
D. K. Smith

2000 ◽  
Vol 14 (29n31) ◽  
pp. 3656-3661 ◽  
Author(s):  
N. L. SAINI ◽  
A. LANZARA ◽  
K. B. GARG ◽  
A. BIANCONI ◽  
T. ITO ◽  
...  

Cu K-edge XANES spectroscopy has been used to study local structure around the Cu-site in three-dimensional oxygen deficient perovkite La 8- x Sr x Cu 8 O 20 system. The combination of E//ab and E//c polarization and high resolution XANES spectra on high quality single crystals has allowed us to distinguish the various features associated with the complex Cu-O networks in the system which have then been compared with those of the La 2- x Sr x CuO 4 system.


2013 ◽  
Vol 1 (36) ◽  
pp. 5619 ◽  
Author(s):  
Giuseppe Paternò ◽  
Anna J. Warren ◽  
Jacob Spencer ◽  
Gwyndaf Evans ◽  
Victoria García Sakai ◽  
...  

1982 ◽  
Vol 37 (5) ◽  
pp. 419-426 ◽  
Author(s):  
M. Polcarová ◽  
J. Brádler

Dynamical theory of the X-ray diffraction on a crystal containing misfit boundary was applied to the interpretation of the contrast observed in X-ray topographs on 90° magnetic domain walls in single crystals of an Fe-Si alloy. The integrated intensities were computed for several cases corresponding to the actual conditions of experiments. Good agreement of theoretical and experi­mental results was obtained.


Sign in / Sign up

Export Citation Format

Share Document