scholarly journals DISLOCATION INTERACTIONS WITH THERMAL PHONONS AND CONDUCTION ELECTRONS.

1972 ◽  
Author(s):  
T Jr Vreeland ◽  
K M Jassby
Author(s):  
C. W. Price

Little evidence exists on the interaction of individual dislocations with recrystallized grain boundaries, primarily because of the severely overlapping contrast of the high dislocation density usually present during recrystallization. Interesting evidence of such interaction, Fig. 1, was discovered during examination of some old work on the hot deformation of Al-4.64 Cu. The specimen was deformed in a programmable thermomechanical instrument at 527 C and a strain rate of 25 cm/cm/s to a strain of 0.7. Static recrystallization occurred during a post anneal of 23 s also at 527 C. The figure shows evidence of dissociation of a subboundary at an intersection with a recrystallized high-angle grain boundary. At least one set of dislocations appears to be out of contrast in Fig. 1, and a grainboundary precipitate also is visible. Unfortunately, only subgrain sizes were of interest at the time the micrograph was recorded, and no attempt was made to analyze the dislocation structure.


1994 ◽  
Vol 164 (4) ◽  
pp. 375 ◽  
Author(s):  
B.V. Vasil'ev ◽  
M.I. Kaganov ◽  
V.L. Lyuboshits

2003 ◽  
Vol 94 (4) ◽  
pp. 436-441 ◽  
Author(s):  
A. K. De ◽  
T. Waterschoot ◽  
B. C. De Cooman

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
David Wallis ◽  
Lars N. Hansen ◽  
Angus J. Wilkinson ◽  
Ricardo A. Lebensohn

AbstractChanges in stress applied to mantle rocks, such as those imposed by earthquakes, commonly induce a period of transient creep, which is often modelled based on stress transfer among slip systems due to grain interactions. However, recent experiments have demonstrated that the accumulation of stresses among dislocations is the dominant cause of strain hardening in olivine at temperatures ≤600 °C, raising the question of whether the same process contributes to transient creep at higher temperatures. Here, we demonstrate that olivine samples deformed at 25 °C or 1150–1250 °C both preserve stress heterogeneities of ~1 GPa that are imparted by dislocations and have correlation lengths of ~1 μm. The similar stress distributions formed at these different temperatures indicate that accumulation of stresses among dislocations also provides a contribution to transient creep at high temperatures. The results motivate a new generation of models that capture these intragranular processes and may refine predictions of evolving mantle viscosity over the earthquake cycle.


2020 ◽  
Vol 39 (1) ◽  
pp. 297-303
Author(s):  
Toru Akasofu ◽  
Masanobu Kusakabe ◽  
Shigeru Tamaki

AbstractThe bonding character of liquid lead telluride \text{PbTe} is thermodynamically investigated in detail. Its possibility as an ionic melt composed of cation {\text{Pb}}^{2+} and anion {\text{Te}}^{2-} is not acceptable, by comparing the ionization energy of \text{Pb} atom, electron affinity of \text{Te} atom and the ionic bonding energy due to the cation {\text{Pb}}^{2+} and anion {\text{Te}}^{2-} with the help of structural information. Solid lead telluride PbTe as a narrow band gap semiconductor might yield easily the overlapping of the tail of valence band and that of conduction one. And on melting, it becomes to an ill-conditioned metallic state, which concept is supported by the electrical behaviors of liquid Pb–Te alloys observed by the present authors. As structural information tells us about the partial remain of some sorts of covalent-type mono-dipole and poly-dipole of the molecule \text{PbTe}, all systems are thermodynamically explained in terms of a mixture of these molecules and cations {\text{Pb}}^{4+} and {\text{Te}}^{2+} and a small amount of the conduction electrons are set free from these elements based on the ternary solution model.


2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Taehyun Kim ◽  
In Ho Cha ◽  
Yong Jin Kim ◽  
Gyu Won Kim ◽  
Andrey Stashkevich ◽  
...  

AbstractThe manipulation of magnetization with interfacial modification using various spin-orbit coupling phenomena has been recently revisited due to its scientific and technological potential for next-generation memory devices. Herein, we experimentally and theoretically demonstrate the interfacial Dzyaloshinskii–Moriya interaction characteristics penetrating through a MgO dielectric layer inserted between the Pt and CoFeSiB. The inserted MgO layer seems to function as a chiral exchange interaction mediator of the interfacial Dzyaloshinskii–Moriya interaction from the heavy metal atoms to ferromagnet ones. The potential physical mechanism of the anti-symmetric exchange is based on the tunneling-like behavior of conduction electrons through the semi-conductor-like ultrathin MgO. Such behavior can be correlated with the oscillations of the indirect exchange coupling of the Ruderman–Kittel–Kasuya–Yosida type. From the theoretical demonstration, we could provide approximate estimation and show qualitative trends peculiar to the system under investigation.


Sign in / Sign up

Export Citation Format

Share Document