Re-equilibration after quenches in athermal martensites:Conversion-delays for vapour to liquid domain-wall phases
Autor: | Turab Lookman, N. Shankaraiah, K. P. N. Murthy, Subodh R. Shenoy |
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Jazyk: | angličtina |
Rok vydání: | 2015 |
Předmět: |
Austenite
Condensed Matter - Materials Science Materials science Condensed matter physics Monte Carlo method Non-equilibrium thermodynamics Materials Science (cond-mat.mtrl-sci) FOS: Physical sciences Condensed Matter Physics Electronic Optical and Magnetic Materials Brillouin zone Martensite Structure factor Harmonic oscillator Entropy (order and disorder) |
Popis: | Entropy barriers and ageing states appear in martensitic structural-transition models, slowly re-equilibrating after temperature quenches, under Monte Carlo dynamics. Concepts from protein folding and ageing harmonic oscillators turn out to be useful in understanding these nonequilibrium evolutions. We show how the athermal, non-activated delay time for seeded parent-phase austenite to convert to product-phase martensite, arises from an identified entropy barrier in Fourier space. In an ageing state of low Monte Carlo acceptances, the strain structure factor makes constant-energy searches for rare pathways, to enter a Brillouin zone `golf hole' enclosing negative energy states, and to suddenly release entropically trapped stresses. In this context, a stress-dependent effective temperature can be defined, that re-equilibrates to the quenched bath temperature. 11 pages, 12 figures. Under process with Phys. Rev. B (2015) |
Databáze: | OpenAIRE |
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