scholarly journals Self-diffusion in plastic flow of amorphous solids

2019 ◽  
Vol 100 (6) ◽  
Author(s):  
Kamran Karimi
Keyword(s):  
Plastic Flow ◽  
Amorphous Solids ◽  
Self Diffusion

Self-Diffusion in the Molecular Crystal Adamantane; Comparison of NMR and Plastic-Flow Methods

1968 ◽  
Vol 20 (22) ◽  
pp. 1227-1228 ◽  
Author(s):  
H. A. Resing ◽  
N. T. Corke ◽  
J. N. Sherwood
Keyword(s):  
Plastic Flow ◽  
Molecular Crystal ◽  
Self Diffusion

Plastic Flow of Solid Mixtures of Li2SO4 and K2SO4

1966 ◽  
Vol 21 (5) ◽  
pp. 593-594
Author(s):  
Arnold Lundén ◽  
Björn Jonson ◽  
Bengt Augustsson
Keyword(s):  
Electrical Conductivity ◽  
Plastic Flow ◽  
Penetration Rate ◽  
Cation Transport ◽  
Considerable Change ◽  
Thermal Pretreatment ◽  
Self Diffusion ◽  
Order Of Magnitude ◽  
Relative Measurements ◽  
High Temperature Modification

The addition of K2SO4 to Li2SO4 causes a considerable change in the rheological properties of the cubic high temperature modification. A simple device for relative measurements of the plastic flow of the salt consisted of a sphere of stainless steel at the end of a steel rod on top of which weights were hung in order to obtain a suitable penetration rate through the salt. This rate depended on the composition of the mixture as well as on the thermal pretreatment of the salt. The temperature dependence was strong; a crude estimation gave an “activation energy” of the order of 2 x 105 cal/mole, i. e. more than an order of magnitude higher than for electrical conductivity or cation self-diffusion. This result is in agreement with the interpretation of the electrical conductivity as being due solely to cation transport.

scholarly journals Structural relaxation and self-diffusion in covalent amorphous solids: Silicon nitride as a model system

2007 ◽  
Vol 102 (4) ◽  
pp. 043516 ◽  
Author(s):  
H. Schmidt ◽  
W. Gruber ◽  
T. Gutberlet ◽  
M. Ay ◽  
J. Stahn ◽  
...  
Keyword(s):  
Silicon Nitride ◽  
Structural Relaxation ◽  
Amorphous Solids ◽  
Model System ◽  
Self Diffusion

Brittle and Ductile Character of Amorphous Solids

2016 ◽  
Vol 8 (3) ◽  
pp. 485-498
Author(s):  
Miguel Lagos ◽  
Raj Das
Keyword(s):  
Glass Transition ◽  
Plastic Flow ◽  
Metallic Glasses ◽  
Bulk Material ◽  
Amorphous Solids ◽  
Amorphous Structure ◽  
Atomic Scale ◽  
Brittle Solid ◽  
Disordered Structure ◽  
The Difference

Abstract.Common silicate glasses are among the most brittle of the materials. However, on warming beyond the glass transition temperature Tg glass transforms into one of the most plastic known materials. Bulk metallic glasses exhibit similar phenomenology, indicating that it rests on the disordered structure instead on the nature of the chemical bonds. The micromechanics of a solid with bulk amorphous structure is examined in order to determine the most basic conditions the system must satisfy to be able of plastic flow. The equations for the macroscopic flow, consistent with the constrictions imposed at the atomic scale, prove that a randomly structured bulk material must be either a brittle solid or a liquid, but not a ductile solid. The theory permits to identify a single parameter determining the difference between the brittle solid and the liquid. However, the system is able of perfect ductility if the plastic flow proceeds in two dimensional plane layers that concentrate the strain. Insight is gained on the nature of the glass transition, and the phase occurring between glass transition and melting.

Residual stress distributions in amorphous solids from atomistic simulations

Soft Matter ◽  
2020 ◽  
Vol 16 (38) ◽  
pp. 8940-8949
Author(s):  
Céline Ruscher ◽  
Jörg Rottler
Keyword(s):  
Residual Stress ◽  
Residual Stresses ◽  
Plastic Flow ◽  
Amorphous Solids ◽  
Atomistic Simulations ◽  
Stress Distributions

The distribution of local residual stresses that controls the properties of plastic flow in athermal amorphous solids is examined with atomistic simulations revealing that deviation from a pseudogap form appears after few percentages of deformation.

Self-Diffusion in Covalent Amorphous Solids – A Comparative Study Using Neutron Reflectometry and SIMS

2007 ◽  
Vol 263 ◽  
pp. 51-56 ◽  
Author(s):  
Harald Schmidt ◽  
Mukul Gupta ◽  
Udo Geckle ◽  
Michael Bruns
Keyword(s):  
Secondary Ion Mass Spectrometry ◽  
Diffusion Length ◽  
Diffusion Processes ◽  
Amorphous Solid ◽  
Amorphous Solids ◽  
Neutron Reflectometry ◽  
Amorphous Silicon Nitride ◽  
Self Diffusion ◽  
Secondary Ion

The self-diffusion of nitrogen is studied in amorphous silicon nitride, which is a model system for a covalently bound amorphous solid with a low atomic mobility where reliable diffusion data are still lacking. Comparative experiments on Si14Nx/Si15Nx (x ≈ 1.33) isotope multilayers were carried out with secondary ion mass spectrometry (SIMS) and neutron reflectometry (NR), respectively. It was found that experiments with SIMS are not very well suited for the determination of diffusivities in a broad temperature range. The minimum diffusion length of about 5-10 nm detectable with this method is too large. At high temperatures (> 1200 °C) the amorphous solid crystallizes before any diffusion is measured and at low temperatures (< 1100 °C) the diffusivities are too low to be detected. In contrast, with neutron reflectometry diffusion lengths in the order of 1 nm and diffusivities down to 10-24 m2 s-1 were measured between 950 and 1250 °C. The potential of this method for the determination of ultra slow diffusion processes is discussed.

scholarly journals Predicting Plastic Flow Events in Athermal Shear-Strained Amorphous Solids

2010 ◽  
Vol 104 (21) ◽  
Author(s):  
Smarajit Karmakar ◽  
Anael Lemaître ◽  
Edan Lerner ◽  
Itamar Procaccia
Keyword(s):  
Plastic Flow ◽  
Amorphous Solids
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