Dependence of electronic polarization on octahedral rotations in TbMnO 3 from first principles

Andrei Malashevich, David Vanderbilt

Research output: Contribution to journalArticlepeer-review

23 Scopus citations

Abstract

The electronic contribution to the magnetically induced polarization in orthorhombic TbMnO3 is studied from first principles. We compare the cases in which the spin cycloid, which induces the electric polarization via the spin-orbit interaction, is in either the b-c or a-b plane. We find that the electronic contribution is negligible in the first case, but much larger, and comparable to the lattice-mediated contribution, in the second case. However, we show that this behavior is an artifact of the particular pattern of octahedral rotations characterizing the structurally relaxed Pbnm crystal structure. To do so, we explore how the electronic contribution varies for a structural model of rigidly rotated MnO6 octahedra and demonstrate that it can vary over a wide range, comparable with the lattice-mediated contribution, for both b-c and a-b spirals. We present a phenomenological model that is capable of describing this behavior in terms of sums of symmetry-constrained contributions arising from the displacements of oxygen atoms from the centers of the Mn-Mn bonds.

Original languageEnglish (US)
Article number224407
JournalPhysical Review B - Condensed Matter and Materials Physics
Volume80
Issue number22
DOIs
StatePublished - Dec 4 2009

ASJC Scopus subject areas

  • Electronic, Optical and Magnetic Materials
  • Condensed Matter Physics

Fingerprint

Dive into the research topics of 'Dependence of electronic polarization on octahedral rotations in TbMnO 3 from first principles'. Together they form a unique fingerprint.

Cite this