title: Electronic correlations determine the phase stability of iron up to the melting temperature.
abstract: We present theoretical results on the high-temperature phase stability and phonon spectra of paramagnetic bcc iron which explicitly take into account many-body effects. Several peculiarities, including a pronounced softening of the [110] transverse (T1) mode and a dynamical instability of the bcc lattice in harmonic approximation are identified. We relate these features to the α-to-γ and γ-to-δ phase transformations in iron. The high-temperature bcc phase is found to be highly anharmonic and appears to be stabilized by the lattice entropy.
authors.affiliation: Theoretical Physics III, Center for Electronic Correlations and Magnetism, Institute of Physics, University of Augsburg, 86135 Augsburg, Germany.
authors.forename: I
authors.initials: I
authors.lastname: Leonov
authors.affiliation: 1] Institute of Metal Physics, 620219 Yekaterinburg GSP-170, Russia [2] Institute of Quantum Materials Science, 620107 Yekaterinburg, Russia.
authors.forename: A I
authors.initials: AI
authors.lastname: Poteryaev
authors.affiliation: 1] Institute of Metal Physics, 620219 Yekaterinburg GSP-170, Russia [2] Institute of Quantum Materials Science, 620107 Yekaterinburg, Russia.
authors.forename: Yu N
authors.initials: YN
authors.lastname: Gornostyrev
authors.affiliation: Institute of Theoretical Physics, University of Hamburg, 20355 Hamburg, Germany.
authors.forename: A I
authors.initials: AI
authors.lastname: Lichtenstein
authors.affiliation: 1] Radboud University Nijmegen, Institute for Molecules and Materials, 6525 AJ Nijmegen, Netherlands [2] Ural Federal University, 620990 Yekaterinburg, Russia.
authors.forename: M I
authors.initials: MI
authors.lastname: Katsnelson
authors.affiliation: 1] Institute of Metal Physics, 620219 Yekaterinburg GSP-170, Russia [2] Ural Federal University, 620990 Yekaterinburg, Russia.
authors.forename: V I
authors.initials: VI
authors.lastname: Anisimov
authors.affiliation: Theoretical Physics III, Center for Electronic Correlations and Magnetism, Institute of Physics, University of Augsburg, 86135 Augsburg, Germany.
authors.forename: D
authors.initials: D
authors.lastname: Vollhardt