Influence of global magnetic state on chemical interactions in high-pressure high-temperature synthesis of B2-Fe2Si
A.V. Ponomareva, A.V. Ruban, N. Dubrovinskaya, L. Dubrovinskiy, and I. A. Abrikosov
The iron-silicon system is important for metallurgy, thermoelectric applications, electrotechnic industry, and geophysics. In particular, Fe2Si system attracted substantial
attention due to reports on very low magnetocrystalline anisotropy of Fe1−xSix (15<x<34) alloys prepared in form nanoribbons by a rapid-quenching technique. We show that effective chemical interactions in an alloy can be tuned by its global magnetic state, which opens exciting possibilities for materials synthesis. Using first-principles theory we demonstrate that at pressure of 20 GPa and at high temperatures, the effective chemical interactions in paramagnetic Fe–Si system are strongly influenced by the magnetic disorder favoring a formation of cubic Fe2Si phase with B2 structure (see the results of our Monte-Carlo simulations in the Figure), which is not present in the alloy phase diagram. Our experiments confirm theoretical predictions, and the B2 Fe2Si alloy is synthesized from Fe–Si mixture using multianvil press.
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Last updated: 10/15/09