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 (T${}_1$) mode and a dynamical instability of the bcc lattice in harmonic approximation are identified. We relate these features to the $\alpha$-to-$\gamma$ and $\gamma$-to-$\delta$ phase transformations in iron. The high-temperature bcc phase is found to be highly anharmonic and appears to be stabilized by the lattice entropy.

8 pages, 3 figures

References in corpus (2)

• Entropy driven stabilization of energetically unstable crystal structures explained from first principles theory
• Magnetism of iron and nickel from rotationally invariant Hirsch-Fye quantum Monte Carlo calculations

Cited by in corpus (16)

• Mode-decomposition based on crystallographic symmetry in the band-unfolding method
• Magnetic Collapse and the Behavior of Transition Metal Oxides at High Pressure
• Dynamic Simulation of Structural Phase Transitions in Magnetic Iron
• Prediction of the Curie temperature considering the dependence of the phonon free energy on magnetic states
• Emergence of quantum critical charge and spin-state fluctuations near the pressure-induced Mott transition in MnO, FeO, CoO, and NiO
• Longitudinal spin fluctuations in bcc and liquid Fe at high temperature and pressure calculated with a supercell approach
• Exchange interactions in iron and nickel: DFT+DMFT study in paramagnetic phase
• Transition from Pauli paramagnetism to Curie-Weiss behaviour in vanadium
• Phase stability of Fe from first-principles: atomistic spin dynamics coupled with ab initio molecular dynamics simulations and thermodynamic integration
• Itinerant magnetism of chromium under pressure: a DFT+DMFT study
• Phase transitions and spin-state of iron in FeO at the conditions of Earth's deep interior
• Magnetic properties of half metal from the paramagnetic phase: DFT+DMFT study of exchange interactions in CrO${}_2$
• MXene Fe2C as a promising candidate for the 2D XY ferromagnet
• A combined inelastic neutron scattering and \textit{ab initio} lattice dynamics study of FeSi
• Coulomb correlations and magnetic properties of L1${}_0$ FeCo: a DFT+DMFT study
• Correlation-driven phonon renormalisation and the equation of state of $\gamma$-cerium