Magnetoelectric (ME) materials are of fundamental interest and show broad potential for technological applications. The common dominant contribution to the ME response is the lattice-mediated one, which is proportional to both the Born electric charge Ze and its analog, the dynamical magnetic charge Zm. Our previous study has shown that exchange striction acting on noncollinear spins induces much larger magnetic charges than those that depend on spin-orbit coupling. The hexagonal manganites RMnO3 and ferrites RFeO3 (R=Sc, Y, In, Ho-Lu) exhibit strong couplings between electric, magnetic, and structural degrees of freedom. The transition-metal ions in the basal plane antiferromagnetically coupled through super-exchange so as to form a 120°noncollinear spin arrangement. In this paper, we present a theoretical study of the magnetic charges, and of the spin-lattice and spin-electronic ME constants, in these hexagonal manganites and ferrites. We clarify the conditions under which exchange striction leads to enhanced Zm values and anomalously large in-plane spin-lattice ME effects.
|Original language||English (US)|
|Journal||Physical Review B - Condensed Matter and Materials Physics|
|State||Published - Jul 6 2015|
All Science Journal Classification (ASJC) codes
- Electronic, Optical and Magnetic Materials
- Condensed Matter Physics