A Study of the Rubber-Like Behavior of Mono-Domain Au-Cd Martensite

1996 ◽  
Vol 459 ◽  
Author(s):  
Xiaobing Ren ◽  
Kazuhiro Otsuka
Keyword(s):  
Interaction Energy ◽  
Elastic Field ◽  
Elastic Interaction ◽  
High Energy ◽  
Stress Fields ◽  
Focused Attention ◽  
Lower Symmetry ◽  
Symmetry Phase ◽  
Low Symmetry ◽  
Original Configuration

ABSTRACTThe origin of the rubber-like behavior in mono-domain Au-Cd martensite was explained in terms of a new model that focused attention on the change of long-range elastic interaction energy among vacancies during a domain reversion. Vacancies in martensite, the lower-symmetry phase, produce stress fields with lower symmetry. During martensite aging, vacancies tend to rearrange themselves to lower elastic interaction energy. The low-symmetry elastic field results in a low-symmetry vacancy configuration. When a stabilized martensite domain reverts to a new domain (twin) under external stress, the original vacancy configuration is inherited to the new domain, but such a configuration becomes a high energy configuration because of the lower symmetry of elastic field, and thus it tends to restore the original configuration by reverse twinning. The above vacancy reconfiguration model is consistent with the fact that the rubber-like behavior is closely related to vacancies.

Elastic Interaction of Defects on Crystal Surfaces

1999 ◽  
Vol 121 (2) ◽  
pp. 129-135 ◽  
Author(s):  
Demitris Kouris ◽  
Alonso Peralta ◽  
Karl Sieradzki
Keyword(s):  
Interaction Energy ◽  
Surface Defects ◽  
Film Growth ◽  
Crystal Surface ◽  
Elastic Field ◽  
Elastic Interaction ◽  
Flow Mode ◽  
Elastic Model ◽  
Far Field ◽  
Embedded Atom

Surface defects corresponding to adatoms, vacancies and steps interact, affecting and often dominating kinetic processes associated with thin-film growth. A discrete harmonic model for the evaluation of the interaction energy between surface defects is presented. It is based on the concept of eigenstrains and allows for the accurate evaluation of the elastic field, both at the immediate vicinity of the defects, as well as in the far field. Results for the interaction energy suggest conditions for which a body-centered-cubic crystal surface will grow in a stable, two-dimensional, step-flow mode. In order to verify the accuracy of the discrete elastic model, we present results of atomic simulations that incorporate Embedded Atom Method (EAM) potentials. The discrete elastic model results compare favorably with results from our atomic EAM simulations and agree with the far-field predictions of continuum elastic theory.

Topotactic Growth of Free-Standing Two-Dimensional Perovskite Niobates with Low Symmetry Phase

Nano Letters ◽  
2021 ◽  
Author(s):  
Fei Zhou ◽  
Yang Li ◽  
Xingqi Liao ◽  
Shuren Lin ◽  
Haizeng Song ◽  
...  
Keyword(s):  
Two Dimensional ◽  
Free Standing ◽  
Symmetry Phase ◽  
Low Symmetry

Algorithms for determining the phase of RHEED oscillations

2015 ◽  
Vol 48 (6) ◽  
pp. 1927-1934 ◽  
Author(s):  
Zbigniew Mitura ◽  
Sergei L. Dudarev
Keyword(s):  
Experimental Data ◽  
Direct Method ◽  
Incident Beam ◽  
Diffraction Theory ◽  
High Energy ◽  
Angle Of Incidence ◽  
High Energy Electron ◽  
Dynamical Diffraction ◽  
Glancing Angle ◽  
Low Symmetry

Oscillations of reflection high-energy electron diffraction (RHEED) intensities are computed using dynamical diffraction theory. The phase of the oscillations is determined using two different approaches. In the first, direct, approach, the phase is determined by identifying the time needed to reach the second oscillation minimum. In the second approach, the phase is found using harmonic analysis. The two approaches are tested by applying them to oscillations simulated using dynamical diffraction theory. The phase of RHEED oscillations observed experimentally is also analysed. Experimental data on the variation of the phase as a function of the glancing angle of incidence, derived using the direct method, are compared with the values computed using both the direct and harmonic methods. For incident-beam azimuths corresponding to low-symmetry directions, both approaches produce similar results.

scholarly journals Temperature controlled c axis elongated low symmetry phase BiFeO3 thin film on STO substrate

AIP Advances ◽  
2013 ◽  
Vol 3 (1) ◽  
pp. 012110 ◽  
Author(s):  
Peng Ren ◽  
Soon Khuen Cho ◽  
Peng Liu ◽  
Lu You ◽  
Xi Zou ◽  
...  
Keyword(s):  
Thin Film ◽  
Bifeo3 Thin Film ◽  
Symmetry Phase ◽  
Temperature Controlled ◽  
Low Symmetry

scholarly journals Eating ‘attentively’ reduces later energy consumption in overweight and obese females

2014 ◽  
Vol 112 (4) ◽  
pp. 657-661 ◽  
Author(s):  
Eric Robinson ◽  
Inge Kersbergen ◽  
Suzanne Higgs
Keyword(s):  
Energy Consumption ◽  
Food Intake ◽  
Energy Intake ◽  
High Energy ◽  
Focused Attention ◽  
Memory Representation ◽  
Snack Food ◽  
Attention Condition ◽  
Appetite Control ◽  
Ad Libitum

Attentional and memory processes underpin appetite control, but whether encouraging overweight individuals to eat more ‘attentively’ can promote reductions in energy consumption is unclear. In the present study with a between-subjects design, a total of forty-eight overweight and obese females consumed a fixed lunchtime meal. Their ad libitum energy intake of high-energy snack food was observed during a second laboratory session that occurred later that day. In the focused-attention condition, participants ate their lunch while listening to audio instructions that encouraged them to pay attention to the food being eaten. In a control condition, participants ate while listening to an audio book with a neutral (non-food-related) content. To test whether focused attention influenced food intake via enhancing the memory of the earlier consumed meal, we measured the participants' memory of their lunchtime meal. Ad libitum snack intake was approximately 30 % lower for participants in the focused-attention condition than for those in the control condition, and this difference was statistically significant. There was limited evidence that attention decreased later food intake by enhancing memory representation of the earlier consumed meal. Eating attentively can lead to a substantial decrease in later energy intake in overweight and obese individuals. Behavioural strategies that encourage a more ‘attentive’ way of eating could promote sustained reductions in energy intake and weight loss.

Perovskite Ti3AlC Carbide Splitting in High Nb Containing TiAl Alloys

2014 ◽  
Vol 1760 ◽  
Author(s):  
Li Wang ◽  
Heike Gabrisch ◽  
Uwe Lorenz ◽  
Frank-Peter Schimansky ◽  
Andreas Stark ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Interaction Energy ◽  
Elastic Interaction ◽  
Morphological Development ◽  
Tial Alloys ◽  
Transmission Electron ◽  
The Matrix

ABSTRACTTransmission electron microscopy has been used to investigate the morphological development of the perovskite (P-) Ti3AlC carbides in the γ matrix of a Ti-45Al-5Nb-0.75C alloy during annealing. P-Ti3AlC carbides in the γ matrix initially have a needle-like shape but during annealing at 800 °C they change to a plate-like shape. In the needle-like shape the carbides are orientated parallel to the [001] direction of the matrix. They extend along the [100]γ or [010]γ direction into plates later and subsequently split into sub particles after extended annealing. It is proposed that the elastic interaction energy between the split sub domains may be the reason that this decomposition into sub-particles is energetically favorable.

On the Manipulation of Nanoscale Self-Assembly by Elastic Field

2003 ◽  
Vol 794 ◽  
Author(s):  
Y.F. Gao
Keyword(s):  
Residual Stress ◽  
Self Assembly ◽  
Elastic Field ◽  
Elastic Interaction ◽  
The Self ◽  
Residual Stress Field ◽  
Feature Size ◽  
External Force Field ◽  
Layered Substrate ◽  
Self Assembled

ABSTRACTMorphological and compositional self-assembly can be manipulated by the long-range elastic field. This paper gives a universal formulation that determines the dependence of energetically favored orientation of those self-assembled structures on the elastic interaction. Elasticity anisotropy can lead to symmetry breaking and herringbone structures. A layered substrate can tune the feature size by modulus mismatch, or tune the orientation if the layers have different orientation preference, or guide the self-assembly by embedded structures. A closed-form result is derived for elastically isotropic layers by using Dundurs parameters. The self-assembled structures can also be affected by a nonuniform residual stress field or external force field. Higher order (nonlinear) perturbation theory, coupling between morphology and composition, and other issues are also addressed in the discussion.

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