Where are the geometrically necessary dislocations accommodating small imprints?

2009 ◽  
Vol 24 (3) ◽  
pp. 647-651 ◽  
Author(s):  
M. Rester ◽  
C. Motz ◽  
R. Pippan
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Twin Boundary ◽  
Crystal Orientation ◽  
Electron Backscatter Diffraction ◽  
Transmission Electron ◽  
Electron Backscatter ◽  
Copper Single Crystals ◽  
Backscatter Diffraction ◽  
Small Misorientation

Electron backscatter diffraction (EBSD) and transmission electron microscopy (TEM) analyses of small indentations in copper single crystals exhibit only slight changes of the crystal orientation in the surroundings of the imprints. Far-reaching dislocations might be the reason for these small misorientation changes. Using EBSD and TEM technique, this work makes an attempt to visualize the far-propagating dislocations by introducing a twin boundary in the vicinity of small indentations. Because dislocations piled up at the twin boundary produce a misorientation gradient, the otherwise far-propagating dislocations can be detected.

Heteroepitaxial CVD Growth of 3C-SiC on Diamond Substrate

2014 ◽  
Vol 778-780 ◽  
pp. 226-229 ◽  
Author(s):  
Véronique Soulière ◽  
Arthur Vo-Ha ◽  
Davy Carole ◽  
Alexandre Tallaire ◽  
Ovidiu Brinza ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Electron Backscatter Diffraction ◽  
Heteroepitaxial Growth ◽  
Silicon Deposition ◽  
Transmission Electron ◽  
Diamond Substrate ◽  
Electron Backscatter ◽  
Cvd Growth ◽  
Backscatter Diffraction

This work presents the successful CVD heteroepitaxial growth of 3C-SiC on diamond (100) substrates. When performing a direct SiC growth at 1500°C on such substrate, it leads to polycrystalline deposit. The use of a substrate pretreatment involving silicon deposition allows forming a more continuous and smoother layer. Electron BackScatter Diffraction and Transmission Electron Microscopy all revealed that the 3C-SiC layer grown on the (100) diamond substrate is monocrystalline and well oriented.

scholarly journals Dislocation Creep of Olivine and Amphibole in Amphibole Peridotites from Åheim, Norway

Minerals ◽  
2021 ◽  
Vol 11 (9) ◽  
pp. 1018
Author(s):  
Sejin Jung ◽  
Takafumi Yamamoto ◽  
Jun-ichi Ando ◽  
Haemyeong Jung
Keyword(s):  
Electron Microscopy ◽  
Slip System ◽  
Electron Backscatter Diffraction ◽  
Microstructural Analysis ◽  
Dislocation Creep ◽  
Transmission Electron ◽  
Electron Backscatter ◽  
Different Types ◽  
Localized Shear Deformation ◽  
Backscatter Diffraction

Amphibole peridotite samples from Åheim, Norway, were analyzed to understand the deformation mechanism and microstructural evolution of olivine and amphibole through the Scandian Orogeny and subsequent exhumation process. Three Åheim amphibole peridotite samples were selected for detailed microstructural analysis. The Åheim amphibole peridotites exhibit porphyroclastic texture, abundant subgrain boundaries in olivine, and the evidence of localized shear deformation in the tremolite-rich layer. Two different types of olivine lattice preferred orientations (LPOs) were observed: B- and A-type LPOs. Electron backscatter diffraction (EBSD) mapping and transmission electron microscopy (TEM) observations revealed that most subgrain boundaries in olivine consist of dislocations with a (001)[100] slip system. The subgrain boundaries in olivine may have resulted from the deformation of olivine with moderate water content. In addition, TEM observations using a thickness-fringe method showed that the free dislocations of olivine with the (010)[100] slip system were dominant in the peridotites. Our data suggest that the subgrain boundaries and free dislocations in olivine represent a product of later-stage deformation associated with the exhumation process. EBSD mapping of the tremolite-rich layer revealed intracrystalline plasticity in amphibole, which can be interpreted as the activation of the (100)[001] slip system.

Synthesis of New-structured PbTiO3 Nanowires With Reversible Bending Properties

2014 ◽  
Vol 67 (5) ◽  
pp. 790
Author(s):  
Jiang Wang ◽  
Jian Li ◽  
Youwen Wang
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Electron Backscatter Diffraction ◽  
X Ray Diffraction ◽  
Acicular Crystal ◽  
One Dimensional ◽  
X Ray ◽  
Transmission Electron ◽  
Bending Process ◽  
Backscatter Diffraction

One-dimensional PbTiO3 nanowires 40–500 nm in diameter and ~400 μm in length were synthesized via a hydrothermal strategy and characterized by X-ray diffraction, electron backscatter diffraction, scanning electron microscopy, and transmission electron microscopy. The results show that the PbTiO3 nanowires exhibit a new acicular crystal structure, which is a tetragonal superstructure composed of a large unit cell of 40 atoms (Pb : Ti : O = 1 : 1 : 3) with a = 12.35 Å, c = 3.83 Å. The PbTiO3 has a feature of unidirectional bending when observed through transmission electron microscopy several times. The bending can be controlled by the electron beam intensity in transmission electron microscopy and the bending process is reversible. Moreover, a possible mechanism for the bending behaviour was also studied, which indicates that macroscopic polarization is in the {110} plane and the direction is not consistent with the electric field, giving the possible driving force for the bending.

scholarly journals Texture and Microtexture of Pure (6N) and Commercially Pure Aluminum after Deformation by Extrusion with Forward-Backward Rotating Die (Kobo)

2016 ◽  
Vol 61 (1) ◽  
pp. 461-468 ◽  
Author(s):  
M. Bieda ◽  
S. Boczkal ◽  
P. Koprowski ◽  
K. Sztwiertnia ◽  
K. Pieła
Keyword(s):  
Electron Microscopy ◽  
Grain Size ◽  
Electron Backscatter Diffraction ◽  
Pure Aluminum ◽  
Pure Aluminium ◽  
Commercially Pure ◽  
Transmission Electron ◽  
Electron Backscatter ◽  
Backscatter Diffraction ◽  
Crystallographic Orientations

Pure aluminium (6N) and commercially pure aluminium (99.7) was deformed by KOBO method. Microstructure and texture of both materials after deformation was analyzed by means of scanning and transmission electron microscopy. Advanced methods of crystallographic orientations measurements like Electron Backscatter Diffraction - EBSD (SEM) and microdiffraction (TEM) was used. Grain size distribution and misorientation between grains in cross and longitudinal sections of the samples were analyzed. Differences in size and homogeneity of the grains were observed in both materials. Pure aluminium was characterized by larger grain size in both sections of extruded material. Whereas commercially pure aluminium reveals smaller grain size and more homogeneous and stable microstructure.

scholarly journals Microstructure Investigations of the Phase Boundaries in the Bridgman TRIP Steel Crystal

2010 ◽  
Vol 160 ◽  
pp. 211-216 ◽  
Author(s):  
D. Borisova ◽  
C. Schimpf ◽  
Andreas Jahn ◽  
V. Klemm ◽  
G. Schreiber ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Trip Steel ◽  
Electron Backscatter Diffraction ◽  
Orientation Distribution ◽  
Phase Boundaries ◽  
Reciprocal Space Mapping ◽  
Transmission Electron ◽  
The Individual ◽  
Backscatter Diffraction

Formation of microstructure defects at the phase boundaries in TRIP steels was investigated with the aid of microstructure analysis on a TRIP steel crystal, which was grown by the Bridgman technique. The microstructure studies comprised scanning electron microscopy (SEM), X-ray diffraction (XRD), electron backscatter diffraction (EBSD), transmission electron microscopy (TEM) and transmission electron microscopy with high resolution (HRTEM). Initial XRD measurements revealed that the crystals under study consist of austenite and ferrite with extremely strong preferred orientations. Subsequent XRD pole figure measurements and EBSD scans have shown that the orientation relationship between austenite and ferrite can be described by the Nishiyama-Wassermann model. For a detailed description of the microstructure of the Bridgman crystal, the orientation distribution of crystallites within the individual phases was investigated using the XRD reciprocal space mapping and the rocking curve measurements. These experiments have shown that the density of microstructure defects is much lower in ferrite than in austenite. The direct information about the defect structures at the phase boundaries between austenite and ferrite was obtained from the TEM micrographs, which revealed complicated micro-twin structures at the boundaries between the neighbouring phases. HRTEM discovered very narrow stripes of ferrite embedded in austenite that were regarded as a source of the microstructure defects in austenite.

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