Skyrmion Nanodomains in Ferroelectric-Antiferroelectric Solid Solutions

Polar skyrmions have demonstrated rich physics and exotic properties for developing novel functionalities in the next-generation nanoelectronics. However, to date, skyrmion nanodomains exist only in a few material systems, such as ferroelectric/dielectric superlattices, free-stranding PbTiO3/SrTiO3 epitaxial bilayers, and ultrathin Pb(Zr,Ti)O3/SrTiO3/Pb(Zr,Ti)O3 sandwiches. These heterostructures are fabricated with elaborately designed boundary conditions to meet the delicate energy balance for stabilizing the topological phases. This critical requirement limits broad applications of skyrmions in electronic devices. Here, we show widespread skyrmion nanodomains in ferroelectric-antiferroelectric solid solutions, which are composed of ferroelectric PbTiO3 and one of antiferroelectric PbSnO3 [Pb(Ti1-x,Snx)O3], PbHfO3 [Pb(Ti1-x,Hfx)O3], and PbZrO3 [Pb(Ti1-x,Zrx)O3], respectively. The skyrmionic textures are formed by engineering the dipole-dipole and antiferrodistortive-dipole couplings in the competition between ferroelectric and antiferroelectric polar orderings, which allows the stabilization of topological phases in both bulk and film forms. A phase diagram is built for ceramics of the three series of solid solutions, revealing composition-dependent domain configurations and stabilization regions of the skyrmion nanodomains. In addition, the non-trivial domains also exhibit improved switching characters, reversible writing/erasure, and long-term retention for electrical manipulation of polar configurations. These findings open a new avenue for the investigation and exploitation of polar skyrmions in ferroelectric-based materials, providing opportunities in topological electronics.