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arXiv · 0803.4135

First-principles study of improper ferroelectricity in TbMnO3

Andrei Malashevich·David Vanderbilt
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Abstract

We have carried out a first-principles theoretical study of the magnetically induced polarization in orthorhombic TbMnO3, a prototypical material in which a cycloidal spin structure generates an electric polarization via the spin-orbit interaction. We compute both the electronic and the lattice-mediated contributions to the polarization and find that the latter is strongly dominant. We analyze the spin-orbit induced forces and lattice displacements from both atomic and mode-decomposition viewpoints, and show that a simple model based on nearest Mn--Mn neighbor Dzyaloshinskii-Moriya interactions is not able to account fully for the results. The direction and magnitude of our computed polarization are in good agreement with experiment.

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Andrei Malashevich, David Vanderbilt. 2008-05-14. First-principles study of improper ferroelectricity in TbMnO3. https://doi.org/10.1103/physrevlett.101.037210

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