Effect of magnetic order on the phase stability of the parent chalcogenide compound FeSe
S. L. Skornyakov+*, I. Leonov×, V. I. Anisimov+*
+Institute of Metal Physics UB of the RAS, 620990 Yekaterinburg, Russia
*Ural Federal University, 620002 Yekaterinburg, Russia
×Theoretical Physics III, Center for Electronic Correlations and Magnetism, Institute of Physics, University of Augsburg,
86135 Augsburg, Germany
Abstract
We present results of first-principle calculation
of the electronic structure and phase
stability of the parent compound of Fe-based superconductors, FeSe, in a
magnetically
ordered state. In particular, we investigate ferromagnetic (FM) and two
different types
of antiferromagnetic (AFM) configurations (with magnetic structure vectors
(π,0) and
(π,π)). Our results for the total energy exhibit a two-minima shape for
the FM and
a standard parabolic-like behavior for the AFM configurations. We find a
remarkable
reconstruction of the electronic structure in the vicinity of the M point
of the Brillouin
zone which is accompanied with a rapid increase of magnetic moment upon
expansion of the
lattice volume. On that basis we propose that both the anomalous behavior of
FeSe upon
expansion of the lattice reported for the paramagnetic state (Phys. Rev. Lett.
115, 106402 (2015))
and that obtained in the present work have a common origin.