1203.2417 (Emmanuel Arras et al.)

Interface-driven phase separation in multifunctional materials: the case
of GeMn ferromagnetic semiconductor    [PDF]

Emmanuel Arras, Frédéric Lançon, Ivetta Slipukhina, Éric Prestat, Mauro Rovezzi, Samuel Tardif, Andrey Titov, Pascale Bayle-Guillemaud, Francesco D'Acapito, André Barski, Vincent Favre-Nicolin, Matthieu Jamet, Joël Cibert, Pascal Pochet

We use extensive first principle simulations to show the major role played by interfaces in the mechanism of phase separation observed in semiconductor multifunctional materials. We make an analogy with the precipitation sequence observed in over-saturated AlCu alloys, and replace the Guinier-Preston zones in this new context. A new class of materials, the $\alpha$-phases, is proposed to understand the formation of the coherent precipitates observed in the GeMn system. The interplay between formation and interface energies is analyzed for these phases and for the structures usually considered in the literature. The existence of the $\alpha$-phases are assessed with arguments both theoretical and experimental.

View original: http://arxiv.org/abs/1203.2417