Dislocation motion around loaded notches in ice single crystals

1999 ◽  
Vol 590 ◽  
Author(s):  
D. Cullen ◽  
X. Hu ◽  
I. Baker ◽  
M. Dudley
Keyword(s):  
Stress Field ◽  
Single Crystals ◽  
Constant Strain Rate ◽  
Dislocation Motion ◽  
Dislocation Loops ◽  
X Ray ◽  
Notch Stress ◽  
Basal Plane Dislocation ◽  
Dislocation Behavior

ABSTRACTSynchrotron X-ray topography has been used to study dislocation behavior around a notch in single crystal ice during in-situ deformation at a constant strain-rate of 1 × 10−8s−1 and a temperature of -8 °C. During deformation a dislocation depleted zone (DDZ) formed above the notch. Modeling the interaction between basal plane dislocation loops and the notch stress field suggested that this DDZ arose from dislocations gliding completely through the specimen.

X-Ray Diffraction Analysis and Modeling of Strain Induced Thermal Cycling in a Thin Aluminum (011) Bicrystal Film

2001 ◽  
Vol 695 ◽  
Author(s):  
D. E. Nowak ◽  
O. Thomas ◽  
S. P. Baker ◽  
E. A. Stach ◽  
K. Balzuweit ◽  
...  
Keyword(s):  
Thermal Cycling ◽  
Dislocation Motion ◽  
X Ray Diffraction ◽  
Metal Thin Films ◽  
X Ray ◽  
Transmission Electron ◽  
Threshold Temperatures ◽  
Slip Planes ◽  
Dislocation Behavior

ABSTRACTHeteroepitaxial films of aluminum bicrystals grown on silicon provide a model system in which to study plasticity in polycrystalline metal thin films. For the bicrystal films, dislocations are confined to move on two different slip plane orientations because of the orientation of the crystals on the substrate. In-situ transmission electron microscopy (TEM) observations during thermal cycling have shown two threshold temperatures for dislocation motion on cooling. A simple model uses the resolved shear stress on the possible slip planes to explain the TEM observations. Mechanisms responsible for the dislocation behavior are studied in-situ during thermal cycling between room temperature and 450°C with x-ray diffraction. The strains are determined using a sin2(Ψ) analysis at each temperature. Direct comparisons are made between the TEM observations, the model and x-ray diffraction results.

Evolution of Pore Ordering during Anodizing of Aluminum Single Crystals: In Situ Small-Angle X-ray Scattering Study

2021 ◽  
Author(s):  
Ilya V. Roslyakov ◽  
Andrei P. Chumakov ◽  
Andrei A. Eliseev ◽  
Alexey P. Leontiev ◽  
Oleg V. Konovalov ◽  
...  
Keyword(s):  
Single Crystals ◽  
Small Angle ◽  
X Ray ◽  
X Ray Scattering ◽  
Scattering Study ◽  
Ray Scattering

X-Ray Reflectivity Study of Single- and Bicrystals of Gold

1990 ◽  
Vol 208 ◽  
Author(s):  
M. R. Fitzsimmons ◽  
E. Burkel ◽  
J. Peisl
Keyword(s):  
Grain Boundary ◽  
Grain Boundaries ◽  
Single Crystals ◽  
Diffuse Scattering ◽  
Direct Evidence ◽  
X Ray ◽  
Specular Reflectivity ◽  
Boundary Measurements

ABSTRACTX-ray reflectivity techniques have been used to characterize the surfaces of 0.4µm thick Au films epitaxially grown on single-crystals of NaCl. Measurements of both the specular and non-specular reflectivity suggest that the Au surface is very rough. The nonspecular reflectivity provides valuable information about the correlation of the heights at different points on the surface. The first in situ reflectivity study of the formation and destruction of a grain boundary shows direct evidence for the existence of diffuse scattering from the grain boundary. Measurements of several [0011 twist grain boundaries suggest that the roughness and texture of an interface depends upon the geometrical orientation of the surrounding substrates.

X-RAY SURFACE DIFFRACTION OF METAL DEPOSITS AT METAL/LIQUID INTERFACES PART I: COPPER DEPOSIT ON Au(100)

1997 ◽  
Vol 04 (06) ◽  
pp. 1173-1178 ◽  
Author(s):  
M. CAPPADONIA ◽  
K. M. ROBINSON ◽  
J. SCHMIDBERGER ◽  
U. STIMMING
Keyword(s):  
Single Crystals ◽  
Perchloric Acid ◽  
Copper Deposit ◽  
Underpotential Deposition ◽  
Gold Surface ◽  
Liquid Interfaces ◽  
X Ray ◽  
Aqueous Perchloric Acid ◽  
Surface Diffraction

In this work the Cu deposition on Au (100) in aqueous perchloric acid has been investigated by in situ X-ray surface diffraction (XRSD). The Cu deposition reaction on gold single crystals exhibits an underpotential deposition (UPD) whereby a fraction of a monolayer is formed. The XRSD measurements show that the Cu UPD layer has a primitive (1×1) structure and that the adsorbed Cu species sit in fourfold hollow sites with a vertical distance between the Cu adlayer and the gold surface of 1.4 Å. The results are discussed in consideration of STM,1 EXAFS2 and XSW3 experiments.

Recrystallization of AA1050 Studied by 3DXRD

2006 ◽  
Vol 519-521 ◽  
pp. 1569-1578
Author(s):  
Dorte Juul Jensen
Keyword(s):  
Single Crystals ◽  
High Energy ◽  
Nucleation And Growth ◽  
X Rays ◽  
X Ray Diffraction ◽  
Orientation Relationships ◽  
X Ray ◽  
3 Dimensional ◽  
Kinetics Of

By 3 dimensional X-ray diffraction (3DXRD) using high energy X-rays from synchrotron sources it is possible to study in-situ the nucleation and growth during recrystallization. In this paper it is described and discussed how 3DXRD can supplement EBSP measurements of nucleation and growth. Three types of studies are considered: i) orientation relationships between nuclei and parent deformed matrix, ii) recrystallization kinetics of individual bulk grains and iii) filming of growing grains in deformed single crystals.

Domain Dynamics under Unipolar Electric Fields for BaTiO3 Single Crystals

2013 ◽  
Vol 582 ◽  
pp. 40-43
Author(s):  
Shotaro Ishikawa ◽  
Yuuki Kitanaka ◽  
Yuji Noguchi ◽  
Masaru Miyayama ◽  
Chikako Moriyoshi ◽  
...  
Keyword(s):  
Synchrotron Radiation ◽  
Single Crystals ◽  
Electric Fields ◽  
Direct Evidence ◽  
Reversible Change ◽  
X Ray ◽  
Domain Structures ◽  
Diffraction Patterns ◽  
Domain Dynamics

Domain structures and dynamics of BaTiO3 single crystals under in-situ electric fields along <110>c were investigated by using synchrotron radiation single-crystal X-ray diffractions. Diffraction patterns clearly show the presence of a 90 ° domain structure in the crystals poled along <110>c. The diffraction analysis provides direct evidence of a reversible change in the volume fractions of two kinds of the 90 o domains under unipolar in-situ electric fields. This reversible change in the domain structures under unipolar fields is suggested to originate from the interaction between spontaneous polarization and defect dipoles composed of acceptor and oxygen vacancy.

Diffraction studies under in situ electric field using a large-area hybrid pixel XPAD detector

2013 ◽  
Vol 46 (4) ◽  
pp. 1151-1161 ◽  
Author(s):  
Pierre Fertey ◽  
Paul Alle ◽  
Emmanuel Wenger ◽  
Bernard Dinkespiler ◽  
Olivier Cambon ◽  
...  
Keyword(s):  
Electric Field ◽  
Single Crystals ◽  
Operation Mode ◽  
Bragg Angle ◽  
Weak Electric Field ◽  
Structural Variations ◽  
Large Area ◽  
X Ray ◽  
Off Pump

A new experimental approach to perform in situ electric field diffraction on single crystals using an on-then-off pump–probe mode in situ (i.e. the field-switching method) with a synchrotron or a laboratory X-ray source is presented. Taking advantage of the fast readout of the XPAD hybrid pixel two-dimensional detector and its programmable functionalities, the operation mode of the detector has been customized to significantly increase the efficiency of the method. The very weak electric field-induced structural response of a piezoelectric crystal can be accurately measured. This allows the piezoelectric tensor to be precisely obtained from Δθ shifts while the structural variations can be modelled using a full set of ΔI/I data. The experimental method and methodology are detailed and tested as a case study on pure piezoelectric compounds belonging to the α-quartz family (SiO2 and GaAsO4 single crystals). Using the two scan modes developed, it is demonstrated that tiny Bragg angle shifts can be measured as well as small field-induced Bragg intensity variations (<1%). The relevance of measurements performed with an X-ray laboratory source is demonstrated: partial data sets collected at synchrotrons can be completed, but more interestingly, a large part of the study can now be realized in the laboratory (medium to strong intensity reflections) in a comparable data collection time.

Direct observation of monoclinic ferroelectric phase and domain switching process in (K0.25Na0.75)NbO3 single crystals

CrystEngComm ◽  
2015 ◽  
Vol 17 (14) ◽  
pp. 2872-2877 ◽  
Author(s):  
Hao Deng ◽  
Haiwu Zhang ◽  
Xiangyong Zhao ◽  
Chao Chen ◽  
Xi'an Wang ◽  
...  
Keyword(s):  
Light Microscopy ◽  
Single Crystals ◽  
Direct Observation ◽  
Ferroelectric Phase ◽  
Domain Switching ◽  
Polarized Light ◽  
Switching Process ◽  
X Ray Diffraction ◽  
X Ray

The domain-switching process of monoclinic K0.25Na0.75NbO3 single crystals were studied by in situ polarized light microscopy and X-ray diffraction.

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