Universal Emergence of Spatially Modulated Structures Induced by Flexoantiferrodistortive Coupling in Multiferroics
The work was supported in part (S.V.K., A.B.) by the U.S. Department of Energy, Basic Energy Sciences, Materials Sciences and Engineering Division, the National Science Foundation Grants No. DMR-1210588 and No. DMR-0820404 (V.G., L.Q.C., and Y.G.).
We proved the existence of a universal flexoantiferrodistortive coupling as a necessary complement to the well-known flexoelectric coupling. The coupling is universal for all antiferrodistortive systems and can lead to the formation of incommensurate, spatially modulated phases in multiferroics. Our analysis can provide a self-consistent mesoscopic explanation for a broad range of modulated domain structures observed experimentally in multiferroics.