Ground-state properties of multivalent manganese oxides: Density functional and hybrid density functional calculations

Autor(en)

Cesare Franchini, Raimund Podloucky, Joachim Paier, Martijn Marsman, Georg Kresse

Abstrakt

We present density functional theory (DFT) calculations for MnO, Mn3 O4, ?- Mn2 O3, and ?-Mn O2, using different gradient corrected functionals, such as Perdew-Burke-Ernzerhof (PBE), PBE+U, and the two hybrid density functional Hartree-Fock methods PBE0 and Heyd-Scuseria-Ernzerhof (HSE). We investigate the structural, electronic, magnetic, and thermodynamical properties of the mentioned compounds. Despite the lack of sufficient experimental information allowing for a comprehensive comparison of our results, we find overall that hybrid functionals provide a more consistent picture than standard PBE. Although PBE+U is limited due to the uncertainty of choosing the parameter U, it nevertheless provides satisfactory results in terms of magnetic properties and energies of formation. This is in line with results of PBE0 and HSE calculations, but the PBE+U approach tends to overestimate the equilibrium volumes, and also it favors a half-metallic state for the more reduced oxides Mn3 O4, ?- Mn2 O3, and ?-Mn O2, rather than an insulating character as derived from the hybrid functional approaches. The comparison of measured valence-band spectra with the HSE density of states offers a further assessment of the capability of hybrid approaches in overcoming the deficiencies of DFT in treating these kinds of materials. © 2007 The American Physical Society.

Organisation(en)

Computergestützte Materialphysik, Institut für Physikalische Chemie, Institut für Theoretische Chemie

Externe Organisation(en)

Technische Universität Wien

Journal

Physical Review B

Band

75

Anzahl der Seiten

11

ISSN

1098-0121

DOI

https://doi.org/10.1103/PhysRevB.75.195128

Publikationsdatum

2007

Peer-reviewed

Ja

ÖFOS 2012

1030 Physik, Astronomie

Link zum Portal

https://ucrisportal.univie.ac.at/de/publications/bab1c6b8-8e15-455d-9bc4-07b34dd321d5