Charge-order-driven ferroelectricity and switching polarization in perovskite superlattices - Prof. Karin Rabe (Rutgers)

13.07.2017 11:00 – 11:30

First-principles calculations of the structure and properties of the 1:1 superlattice of LaVO$_{3}$ and SrVO$_{3}$ show a low-energy state in which layered charge ordering combines with the layered La/Sr cation ordering to produce a polar structure with a large nonzero spontaneous polarization normal to the interfaces. The magnitude of the polarization is comparable to that of conventional ferroelectrics. However, it is produced not by symmetry-lowering ionic displacements from a high-symmetry structure, but by electron transfer between the V$^{3+}$ and V$^{4+}$ layers. We relate the polar variants by displacements of the relevant Wannier center, and discuss some unusual behavior of the polarization that may arise in this system and related materials.

Lieu

Bâtiment: Ecole de Physique

MaNEP

entrée libre