Antiferroelectrics characterized by voltage-driven reversible transitions between antiparallel and parallel polarity are promising for cutting-edge electronic and electrical power applications. Wide-ranging explorations revealing the macroscopic performances and microstructural characteristics of typical antiferroelectric systems have been conducted. However, the underlying mechanism has not yet been fully unraveled, which depends largely on the atomistic processes. Herein, based on atomic-resolution transmission electron microscopy, the deterministic phase transition pathway along with the underlying lattice-by-lattice details in lead zirconate thin films was elucidated. Specifically, we identified a new type of ferrielectric-like dipole configuration with both angular and amplitude modulations, which plays the role of a precursor for a subsequent antiferroelectric to ferroelectric transformation. With the participation of the ferrielectric-like phase, the phase transition pathways driven by the phase boundary have been revealed. We provide new insights into the consecutive phase transformation in low-dimensional lead zirconate, which thus would promote potential antiferroelectric-based multifunctional devices.

A dipole wave is composed of head-to-tail connected electric dipoles in the form of sine function. Potential applications in information carrying, transporting, and processing are expected, and logic circuits based on nonlinear wave interaction are promising for dipole waves. Although similar spin waves are well known in ferromagnetic materials for their roles in some physical essence, electric dipole wave behavior and even its existence in ferroelectric materials are still elusive. Here, we observe the atomic morphology of large-scale dipole waves in PbTiO3/SrTiO3 superlattice mediated by tensile epitaxial strains on scandate substrates. The dipole waves can be expressed in the formula of y = Asin (2πx/L) + y0, where the wave amplitude (A) and wavelength (L) correspond to 1.5 and 6.6 nm, respectively. This study suggests that by engineering strain at the nanoscale, it should be possible to fabricate unknown polar textures, which could facilitate the development of nanoscale ferroelectric devices.

Inducing clear ferroelectricity in the quantum paraelectric SrTiO 3 is important for triggering methods to discover hidden phases in condensed matter physics. Several methods such as isotope substitution and freestanding membranes could introduce ferroelectricity in SrTiO 3 toward nonvolatile memory applications. However, the stable transformation from quantum paraelectric SrTiO 3 to ferroelectricity SrTiO 3 at room temperature still remains challenging. Here, we used multiple nano-engineering in (SrTiO 3 ) 0.65 /(CeO 2 ) 0.35 films to achieve an emergent room-temperature ferroelectricity. It is shown that the CeO 2 nanocolumns impose large out-of-plane strains and induce Sr/O deficiency in the SrTiO 3 matrix to form a clear tetragonal structure, which leads to an apparent room-temperature ferroelectric polarization up to 2.5 μC/cm 2 . In collaboration with density functional theory calculations, it is proposed that the compressive strains combined with elemental deficiency give rise to local redistribution of charge density and orbital order, which induce emergent tetragonality of the strained SrTiO 3 . Our work thus paves a pathway for architecting functional systems in perovskite oxides using a multiple nano-design.