Abstract
When a disordered Cu0.75Au0.25 alloy is cooled down below Tc (≤ 663K), it orders into the L 12 phase (Cu3Au), exhibiting initially a microstructure of domain walls. Whereas at long time (t) the average size of the domains develops as a power law , at short times a distinct incubation period is observed experimentally. We show that a first-principles description of a configurational Hamiltonian via the 'mixed-space cluster expansion' that includes both 'chemical' and 'strain' effects produces such an incubation period in MonteCarlo simulations, whereas the classical short-ranged ('chemical' only) Ising description does not. We find that the origin of this delay time is the elastic energy, ensuing from the Cu-Au atomic size mismatch.
Original language | English |
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Article number | 086201 |
Journal | Journal of Physics Condensed Matter |
Volume | 19 |
Issue number | 8 |
DOIs | |
State | Published - Feb 28 2007 |