scholarly journals Irradiation enhanced diffusion and diffusional creep in U₃Si₂

2020 ◽  
Author(s):  
Michael William Donald Cooper ◽  
K. A. Gamble ◽  
Christopher Matthews ◽  
Anders David Ragnar Andersson
Keyword(s):  
Diffusional Creep ◽  
Enhanced Diffusion

Ion Beam Mixing of Ni-Ti Bilayered Thin Films

1985 ◽  
Vol 43 ◽  
pp. 290-291
Author(s):  
A. K. Rai ◽  
R. S. Bhattacharya ◽  
M. H. Rashid
Keyword(s):  
Crystal Structure ◽  
Thin Films ◽  
Amorphous Alloys ◽  
Ion Beam ◽  
Ion Bombardment ◽  
High Energy ◽  
Mixing Efficiency ◽  
Ion Beam Mixing ◽  
Enhanced Diffusion ◽  
Binary Metal

Ion beam mixing has recently been found to be an effective method of producing amorphous alloys in the binary metal systems where the two original constituent metals are of different crystal structure. The mechanism of ion beam mixing are not well understood yet. Several mechanisms have been proposed to account for the observed mixing phenomena. The first mechanism is enhanced diffusion due to defects created by the incoming ions. Second is the cascade mixing mechanism for which the kinematicel collisional models exist in the literature. Third mechanism is thermal spikes. In the present work we have studied the mixing efficiency and ion beam induced amorphisation of Ni-Ti system under high energy ion bombardment and the results are compared with collisional models. We have employed plan and x-sectional veiw TEM and RBS techniques in the present work.

Parallel Glide: A Fundamentally Different Type of Dislocation Motion in Ultrathin Metal Films

2003 ◽  
Vol 779 ◽  
Author(s):  
T. John Balk ◽  
Gerhard Dehm ◽  
Eduard Arzt
Keyword(s):  
Thermal Cycling ◽  
Grain Boundaries ◽  
Film Surface ◽  
Metal Films ◽  
Geometric Constraints ◽  
Film Stress ◽  
Diffusional Creep ◽  
Creep Model ◽  
Substrate Interface ◽  
Film Substrate

AbstractWhen confronted by severe geometric constraints, dislocations may respond in unforeseen ways. One example of such unexpected behavior is parallel glide in unpassivated, ultrathin (200 nm and thinner) metal films. This involves the glide of dislocations parallel to and very near the film/substrate interface, following their emission from grain boundaries. In situ transmission electron microscopy reveals that this mechanism dominates the thermomechanical behavior of ultrathin, unpassivated copper films. However, according to Schmid's law, the biaxial film stress that evolves during thermal cycling does not generate a resolved shear stress parallel to the film/substrate interface and therefore should not drive such motion. Instead, it is proposed that the observed dislocations are generated as a result of atomic diffusion into the grain boundaries. This provides experimental support for the constrained diffusional creep model of Gao et al.[1], in which they described the diffusional exchange of atoms between the unpassivated film surface and grain boundaries at high temperatures, a process that can locally relax the film stress near those boundaries. In the grains where it is observed, parallel glide can account for the plastic strain generated within a film during thermal cycling. One feature of this mechanism at the nanoscale is that, as grain size decreases, eventually a single dislocation suffices to mediate plasticity in an entire grain during thermal cycling. Parallel glide is a new example of the interactions between dislocations and the surface/interface, which are likely to increase in importance during the persistent miniaturization of thin film geometries.

scholarly journals Protein Motors Induced Enhanced Diffusion In Intracellular Transport

2010 ◽  
Vol 98 (3) ◽  
pp. 167a
Author(s):  
Ivan Santamaria-Holek
Keyword(s):  
Intracellular Transport ◽  
Enhanced Diffusion ◽  
Protein Motors

Effects of Concurrent Co or Ti Silicidation on Transient Diffusion and End-of-Range Damage in Phosphorus Implanted Silicon

1992 ◽  
Vol 262 ◽  
Author(s):  
J.W. Honeycutt ◽  
J. Ravi ◽  
G. A. Rozgonyi
Keyword(s):  
Secondary Ion Mass Spectrometry ◽  
Complete Removal ◽  
Dislocation Loops ◽  
Enhanced Diffusion ◽  
Depth Profiles ◽  
Enhanced Dissolution ◽  
Implantation Damage ◽  
Transmission Electron ◽  
Defect Behavior ◽  
Secondary Ion

ABSTRACTThe effects of Ti and Co silicidation on P+ ion implantation damage in Si have been investigated. After silicidation of unannealed 40 keV, 2×1015 cm-2 P+ implanted junctions by rapid thermal annealing at 900°C for 10–300 seconds, secondary ion mass spectrometry depth profiles of phosphorus in suicided and non-silicided junctions were compared. While non-silicided and TiSi2 suicided junctions exhibited equal amounts of transient enhanced diffusion behavior, the junction depths under COSi2 were significantly shallower. End-of-range interstitial dislocation loops in the same suicided and non-silicided junctions were studied by planview transmission electron microscopy. The loops were found to be stable after 900°C, 5 minute annealing in non-silicided material, and their formation was only slightly effected by TiSi2 or COSi2 silicidation. However, enhanced dissolution of the loops was observed under both TiSi2 and COSi2, with essentially complete removal of the defects under COSi2 after 5 minutes at 900°C. The observed diffusion and defect behavior strongly suggest that implantation damage induced excess interstitial concentrations are significantly reduced by the formation and presence of COSi2, and to a lesser extent by TiSi2. The observed time-dependent defect removal under the suicide films suggests that vacancy injection and/or interstitial absorption by the suicide film continues long after the suicide chemical reaction is complete.

scholarly journals Enhanced diffusion-edited NMR spectroscopy of mixtures using chromatographic stationary phases

2003 ◽  
Vol 100 (17) ◽  
pp. 9696-9698 ◽  
Author(s):  
S. Viel ◽  
F. Ziarelli ◽  
S. Caldarelli
Keyword(s):  
Nmr Spectroscopy ◽  
Stationary Phases ◽  
Enhanced Diffusion

scholarly journals Direction-dependent turning leads to anisotropic diffusion and persistence

2021 ◽  
pp. 1-37
Author(s):  
N. LOY ◽  
T. HILLEN ◽  
K. J. PAINTER
Keyword(s):  
Anisotropic Diffusion ◽  
Cell Movement ◽  
Orientation Dependence ◽  
Transport Equations ◽  
Heterogeneous Environment ◽  
Enhanced Diffusion ◽  
Mesoscopic Level

Cells and organisms follow aligned structures in their environment, a process that can generate persistent migration paths. Kinetic transport equations are a popular modelling tool for describing biological movements at the mesoscopic level, yet their formulations usually assume a constant turning rate. Here we relax this simplification, extending to include a turning rate that varies according to the anisotropy of a heterogeneous environment. We extend known methods of parabolic and hyperbolic scaling and apply the results to cell movement on micropatterned domains. We show that inclusion of orientation dependence in the turning rate can lead to persistence of motion in an otherwise fully symmetric environment and generate enhanced diffusion in structured domains.

Blocky Sb/C Anodes with Enhanced Diffusion Kinetics for High‐Rate and Ultra‐Long Cyclability Sodium Dual‐Ion Batteries

2021 ◽  
Author(s):  
Hong-Ji Li ◽  
Jing-Jing Li ◽  
Zhe Chen ◽  
Zhen-Zhen Wang ◽  
Jin Qu ◽  
...  
Keyword(s):  
High Rate ◽  
Diffusion Kinetics ◽  
Enhanced Diffusion

Enhanced diffusion upon amorphous-to-nanocrystalline phase transition in Mo/B4C/Si layered systems

2010 ◽  
Vol 108 (1) ◽  
pp. 014314 ◽  
Author(s):  
V. I. T. A. de Rooij-Lohmann ◽  
A. E. Yakshin ◽  
R. W. E. van de Kruijs ◽  
E. Zoethout ◽  
A. W. Kleyn ◽  
...  
Keyword(s):  
Phase Transition ◽  
Nanocrystalline Phase ◽  
Layered Systems ◽  
Enhanced Diffusion
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