Radiation-induced micr-structures as ground states of the SH energy functional
Résumé
We demonstrate that the Swift-Hohenberg functional as used to describe patterning observed in out of equilibrium systems such as diblock copolymers, Rayleigh-Benard convection and thin film magnetic garnets, can be applied to radiation-induced patterns that occur in non-miscible alloys. By comparing ground states obtained from the minimization of this functional and a 2D numerical simulation performed on an irradiated AgCu material which is the archetype of a non-miscible alloy we show that the Swift-Hohenberg functional provides all possible patterns generated under irradiation and the solubility limits of radiation-induced precipitates in these patterns. To rationalize the formation of these radiation-induced patterns, we propose a generic "pseudo phase diagram" that relies not only on the irradiation flux and temperature but also the overall composition of the alloy. Tuning this overall composition offers the opportunity to tailor new materials with various micro-structures overcoming the limitation of the equilibrium phase diagram.