Przemysław Piekarz

Mechanism of the Verwey transition in magnetite.

By combining ab initio results for the electronic structure and phonon spectrum with the group theory, we establish the origin of the Verwey transition in Fe3O4. Two primary order parameters with X3 and Delta5 symmetries are identified. They induce the phase transformation from the high-temperature cubic to the low-temperature monoclinic structure. The on-site Coulomb interaction U between 3d electrons at Fe ions plays a crucial role in this transition--it amplifies the coupling of phonons to conduction electrons and thus opens a gap at the Fermi energy.

Origin of the Verwey transition in magnetite: Group theory, electronic structure, and lattice dynamics study

The Verwey phase transition in magnetite has been analyzed using the group theory methods. It is found that two order parameters with the symmetries

Vibrational Properties of {alpha}- and {sigma}-phase Fe-Cr alloy.

{X}_{3}

Anharmonicity due to Electron-Phonon Coupling in Magnetite

and

Structure and elastic properties of Mg(OH)2 from density functional theory

{\ensuremath{\Delta}}_{5}

Short-Range Correlations in Magnetite above the Verwey Temperature

induce the structural transformation from the high-temperature cubic to the low-temperature monoclinic phase. The coupling between the order parameters is described by the Landau free energy functional. The electronic and crystal structure for the cubic and monoclinic phases were optimized using the ab initio density functional method. The electronic structure calculations were performed within the generalized gradient approximation including the on-site interactions between

The ab initio study of unconventional superconductivity in CeCoIn5 and FeSe

3d

Comparative ab initio study of lattice dynamics and thermodynamics of Fe2SiO4- and Mg2SiO4-spinels.

electrons at iron ions\char22{}the Coulomb element

Multiple magnetic phase transitions in Tb3Cu4Si4

U

Lattice dynamics of the heavy-fermion compound URu2Si2

and Hunds exchange