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arXiv · 1708.04925

The Microscopic Model of BiFeO$_3$

Randy S. Fishman
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Abstract

Many years and great effort have been spent constructing the microscopic model for the room temperature multiferroic BiFeO3 However, earlier models implicitly assumed that the cycloidal wavevector q was confined to one of the three-fold symmetric axis in the hexagonal plane normal to the electric polarization. Because recent measurements indicate that q can be rotated by a magnetic field, it is essential to properly treat the anisotropy that confines q at low fields. We show that the anisotropy energy $-K_3 S^6 \sin^6 θ\cos 6 ϕ$ confines the wavevectors q to the three-fold axis $ϕ=0$ and $+-2 π/3$ within the hexagonal plane with $θ= π/2$.

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Randy S. Fishman. 2017-08-16. The Microscopic Model of BiFeO$_3$. https://doi.org/10.1016/j.physb.2017.09.103

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