Investigation of the dislocation structure in Czochralski germanium crystals grown in [211] and [110] growth direction

CrystEngComm ◽  
2021 ◽  
Author(s):  
Kevin-Peter Gradwohl ◽  
Melissa Roder ◽  
Andreas Danilewsky ◽  
Rajappan Radhakrishnan Sumathi
Keyword(s):  
Dislocation Structure ◽  
Czochralski Method ◽  
Growth Direction ◽  
Single Crystalline ◽  
X Ray ◽  
White Beam ◽  
Dislocation Densities ◽  
Crystalline Germanium

The dislocation structure of single-crystalline germanium crystals grown by the Czochralski method in [211] and [110] direction has been examined by white beam X-ray topography. The dislocation densities in different...

The Nucleation and Propagation of Threading Dislocations with C-Component of Burgers Vector in PVT-Grown 4H-SiC

2013 ◽  
Vol 740-742 ◽  
pp. 217-220 ◽  
Author(s):  
Fang Zhen Wu ◽  
Michael Dudley ◽  
Huan Huan Wang ◽  
Sha Yan Byrapa ◽  
Shun Sun ◽  
...  
Keyword(s):  
Basal Plane ◽  
Opposite Sign ◽  
Growth Direction ◽  
Threading Dislocations ◽  
Burgers Vector ◽  
X Ray ◽  
White Beam

Studies of threading dislocations with Burgers vector of c+a have been carried out using synchrotron white beam X-ray topography. The nucleation and propagation of pairs of opposite sign threading c+a dislocations is observed. Overgrowth of inclusions by growth steps leads to lattice closure failure and the stresses associated with this can be relaxed by the nucleation of opposite sign pairs of dislocations with Burgers vector c+a. Once these dislocations are nucleated they propagate along the c-axis growth direction, or can be deflected onto the basal plane by overgrowth of macrosteps. For the c+a dislocations, partial deflection can occasionally occur, e.g. the a-component deflects onto basal plane while the c-component continuously propagates along the growth direction. One factor controlling the details of these deflection processes is suggested to be related to the ratio between the height of the overgrowing macrostep and that of the surface spiral hillock associated with the threading growth dislocations with c-component of Burgers vector.

White-Beam Transmission Characterization of Texture in Mo Thin Films and Mo/W Multilayers

1993 ◽  
Vol 317 ◽  
Author(s):  
Marc Vill ◽  
S. G. MALHOTRA ◽  
Z. Rek ◽  
S. M. Yalisove ◽  
J. C. Bilello
Keyword(s):  
Growth Direction ◽  
X Rays ◽  
X Ray Diffraction ◽  
Orientation Data ◽  
X Ray ◽  
White Beam ◽  
Out Of Plane ◽  
Transmission Study ◽  
Beam Transmission ◽  
Plane Diffraction

ABSTRACTSynchrotron white-beam (polychromatic) x-ray radiation was used in a transmission Laue study of texture in monolithic mo films and Mo/W Multilayers. High intensity synchrotron radiation permits x-ray diffraction study of mo specimens >100μm in thickness, while 6μm is the practical thickness limit for a transmission study using a rotating anode x-ray source. The transmission Laue technique permits the collection of preferred orientation data from several families of diffracting planes on one photographic exposure. Polychromatic x-rays facilitate collection of diffraction information from a range of planar orientations without altering the orientation of the sample with respect to the incident x-ray beam. The texture information from a 35μm thick monolithic mo film and a 31μm thick multilayer of mo and W is presented. Two-fold symmetry seen in the {211} plane diffraction ring of the multilayer demonstrated both an in-plane and out-of-plane texture with a <110> growth direction. Three fold symmetry seen in the {310} and {222} plane diffraction rings of the monolithic mo film demonstrated both in-plane and out-of-plane texture which suggests a <111> growth direction.

scholarly journals The Influence of the Cooling Bores on Crystal Orientation and Lattice Parameter in Single-Crystalline Cored Turbine Blades

Materials ◽  
2021 ◽  
Vol 14 (14) ◽  
pp. 3842
Author(s):  
Jacek Krawczyk ◽  
Włodzimierz Bogdanowicz ◽  
Jan Sieniawski
Keyword(s):  
Solidification Front ◽  
Crystal Orientation ◽  
Turbine Blades ◽  
Lattice Parameter ◽  
Growth Direction ◽  
X Ray Diffraction ◽  
Single Crystalline ◽  
X Ray ◽  
Vertical Bridgman ◽  
Α Angle

The areas located near the cooling bores of single-crystalline cored turbine blades made of nickel-based CMSX-4 superalloy were studied. The blades were solidified by the vertical Bridgman technique in the industrial ALD furnace. Longitudinal sections of the blades were studied by Scanning Electron Microscopy, X-ray diffraction topography, X-ray diffraction measurements of the γ′-phase lattice parameter a, and the α angle of the primary crystal orientation. The local changes in α were analyzed in relation to the changes of the dendrite’s growth direction near the cooling bores. It was found that in the area approximately 3 ÷ 4 mm wide around the cooling bores, changes of α and a, both in the blade root and in the airfoil occurred. The local temperature distribution near the cooling bores formed a curved macroscopic solidification front, which caused changes in the chemical composition and, consequently, changes in the a value in a range of 0.002 Å to 0.014 Å. The mechanism of alloying elements segregation by tips of the dendrites on the bent solidification front was proposed. The multi-scale analysis that allows determining a relation between processes proceed both on a millimeter-scale and a micrometric and nanometric scale, was applied in the studies.

Material Structure of Microcrystalline Silicon Deposited with an Expanding Thermal Plasma

2003 ◽  
Vol 762 ◽  
Author(s):  
C. Smit ◽  
D.L. Williamson ◽  
M.C.M. van de Sanden ◽  
R.A.C.M.M. van Swaaij
Keyword(s):  
Thermal Plasma ◽  
Hydrogen Plasma ◽  
Plasma Chemistry ◽  
Plasma Source ◽  
Growth Direction ◽  
Interaction Time ◽  
Material Structure ◽  
Average Particle ◽  
Microcrystalline Silicon ◽  
X Ray

AbstractExpanding thermal plasma CVD (ETP CVD) has been used to deposit thin microcrystalline silicon films. In this study we varied the position at which the silane is injected in the expanding hydrogen plasma: relatively far from the substrate and close to the plasma source, giving a long interaction time of the plasma with the silane, and close to the substrate, resulting in a short interaction time. The material structure is studied extensively. The crystalline fractions as obtained from Raman spectroscopy as well as from X-ray diffraction (XRD) vary from 0 to 67%. The average particle sizes vary from 6 to 17 nm as estimated from the (111) XRD peak using the Scherrer formula. Small angle X-ray scattering (SAXS) and flotation density measurements indicate void volume fractions of about 4 to 6%. When the samples are tilted the SAXS signal is lower than for the untilted case, indicating elongated objects parallel to the growth direction in the films. We show that the material properties are influenced by the position of silane injection in the reactor, indicating a change in the plasma chemistry.

scholarly journals Dislocation densities in a low-carbon steel during martensite transformation determined by in situ high energy X-Ray diffraction

2021 ◽  
Vol 800 ◽  
pp. 140249
Author(s):  
Juan Macchi ◽  
Steve Gaudez ◽  
Guillaume Geandier ◽  
Julien Teixeira ◽  
Sabine Denis ◽  
...  
Keyword(s):  
Carbon Steel ◽  
Martensite Transformation ◽  
Low Carbon Steel ◽  
High Energy ◽  
Low Carbon ◽  
X Ray Diffraction ◽  
X Ray ◽  
Dislocation Densities

Synchrotron White-Beam X-Ray Topography Analysis of the Defect Structure of HVPE-GaN Substrates

2015 ◽  
Vol 4 (8) ◽  
pp. P324-P330 ◽  
Author(s):  
L. Kirste ◽  
A. N. Danilewsky ◽  
T. Sochacki ◽  
K. Köhler ◽  
M. Zajac ◽  
...  
Keyword(s):  
Defect Structure ◽  
X Ray ◽  
White Beam ◽  
Topography Analysis

SEM Characterization of Silicon Layers Grown on Carbon Foil

2009 ◽  
Vol 156-158 ◽  
pp. 473-476 ◽  
Author(s):  
Sergei K. Brantov ◽  
A.V. Eltzov ◽  
Olga V. Feklisova ◽  
Eugene B. Yakimov
Keyword(s):  
Dislocation Density ◽  
Defect Structure ◽  
Growth Direction ◽  
Carbon Foil ◽  
Twin Boundaries ◽  
X Ray ◽  
Electron Backscattering Diffraction ◽  
Silicon Ribbon ◽  
Selective Chemical

Characterization of defect structure in silicon ribbon grown on carbon foil has been carried out. The structure of grown Si layers and a dislocation density in these layers have been studied using selective chemical etching and the Electron Backscattering Diffraction. It is observed that the layers consist of rather large grains, the majority of which is elongated along the growth direction with a similar surface orientation and with a misorientation angle between neighboring grains of 60º. This means that such grains are separated by the (111) twin boundaries. The dislocation density in different grains is found to vary from 102 to 107cm-2. The energy dispersive X-Ray microanalysis has shown that some twin boundaries are enriched with carbon.

X-ray photoemission and bremsstrahlung isochromat spectroscopy of bulk single crystalline SixGe1−x alloys

1998 ◽  
Vol 88-91 ◽  
pp. 395-398 ◽  
Author(s):  
Y. Saito ◽  
S. Fujimori ◽  
S. Suzuki ◽  
S. Sato ◽  
T. Honda ◽  
...  
Keyword(s):  
Single Crystalline ◽  
X Ray
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