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arXiv · 0811.1472

Strong short-range magnetic order in a frustrated FCC lattice and its possible role in the iron structural transformation

A. N. Ignatenko·A. A. Katanin·V. Yu. Irkhin
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Abstract

We investigate magnetic properties of a frustrated Heisenberg antiferromagnet with a face-centered cubic (FCC) lattice and exchange interactions between the nearest- and next-nearest neighbours, J1 and J2. In a collinear phase with the wave vector Q = (pi,pi,pi) the equations of the self-consistent spin-wave theory for the sublattice magnetization and the average short range order parameter are obtained and numerically solved. The dependence of the Neel temperature T_N on the ratio J2/J1 is obtained. It is shown, that at strong enough frustration there is a wide temperature region above T_N with strong short range magnetic order. Application of this result to description of structural phase transition between alpha and gamma-phase of Fe is considered.

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A. N. Ignatenko, A. A. Katanin, V. Yu. Irkhin. 2008-11-10. Strong short-range magnetic order in a frustrated FCC lattice and its possible role in the iron structural transformation. https://doi.org/10.1134/s0021364008100093

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