Abstract
Electric polarization in conventional paraelectric/ferroelectric oxides usually involves the displacement of nonmagnetic transition-metal ions with an empty shell. Here we unravel an unusual mechanism for electric polarization based on the displacement of magnetic ions. Our simulations suggest that the competition between the long-range Coulomb interaction and short-range Pauli repulsion in a bipyramidal unit with proper lattice parameters would favor an off-center displacement of , which directly induces a local electric dipole. As a prototype example, we show that the electric dipole of a bipyramid in hexaferrites leads to a different family of magnetic quantum paraelectrics. The manipulation of this unique magnetic-ion-induced displacive electric polarization in a bipyramid could open up a promising route to generating unconventional dielectrics, ferroelectrics, and multiferroics.
- Received 2 March 2014
- Revised 3 November 2014
DOI:https://doi.org/10.1103/PhysRevB.90.180404
©2014 American Physical Society