Structural and ferroelectric transitions in magnetic nickelate PbNiO3

Autor(en)

X. F. Hao, A. Stroppa, P. Barone, A. Filippetti, C. Franchini, S. Picozzi

Abstrakt

Density functional calculations have been tremendously useful in

understanding the microscopic origin of multiferroicity and in

quantifying relevant properties in many multiferroics and

magnetoelectrics. Here, we focus on a relatively new and promising

compound, PbNiO₃. The structural, electronic and magnetic properties of its two polymorphs, i.e. the orthorhombic structure with space group Pnma and the rhombohedral LiNbO₃-type structure with space group R3c have been studied by using density functional calculations within DFT + U

and hybrid functional schemes. Our data convey an accurate description

of the pressure-induced phase transition from the rhombohedral to

orthorhombic phase at a predicted critical pressure of 5 GPa in

agreement with the measured value of 3 GPa. Both phases show the G-type

antiferromagnetic configuration as a magnetic ground state, but differ

in the spatial anisotropy associated with nearest-neighbor exchange

couplings, which is strongly weakened in the rhombohedral LiNbO₃-type phase. The predicted large ferroelectric polarization of the rhombohedral phase (Hao et al 2012 Phys. Rev.

B 014116) has been re-explored and analyzed in detail using partial

density of states, Born effective charge tensors, charge density

difference, electron localization function analysis and distortion mode

analysis. The asymmetric bonding between the Pb 6s and O 2p orbitals

along the [111]-direction is responsible for the polar cationic

displacement, giving rise to a predicted large ferroelectric

polarization as high as  ~ 100 μC cm⁻².

Organisation(en)

Computergestützte Materialphysik

Externe Organisation(en)

Technische Universität Wien, Consiglio Nazionale delle Ricerche, Center for Computational Materials Science, CMS, Università degli Studi di Cagliari

Journal

New Journal of Physics

Band

16

Anzahl der Seiten

20

ISSN

1367-2630

DOI

https://doi.org/10.1088/1367-2630/16/1/015030

Publikationsdatum

01-2014

Peer-reviewed

Ja

ÖFOS 2012

103009 Festkörperphysik, 103015 Kondensierte Materie, 103025 Quantenmechanik, 103036 Theoretische Physik

Schlagwörter

Link zum Portal

https://ucrisportal.univie.ac.at/de/publications/feeb6d79-80d7-437c-8cfe-6992aed64411