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Abstract Van der Waals integration of freestanding perovskite-oxide membranes with two-dimensional semiconductors has emerged as a promising strategy for developing high-performance electronics, such as field-effect transistors. In these innovative field-effect transistors, the oxide membranes have primarily functioned as dielectric layers, yet their great potential for structural tunability remains largely untapped. Free of epitaxial constraints by the substrate, these freestanding membranes exhibit remarkable structural tunability, providing a unique material system to achieve huge strain gradients and pronounced flexoelectric effects. Here, by harnessing the excellent structural tunability of PbTiO3 membranes and modulating the underlying substrate’s elasticity, we demonstrate the tip-pressure-induced polarization switching with an ultralow pressure (down to 0.06 GPa). Moreover, as an application demonstration, we develop a prototype non-volatile ferroelectric field-effect transistor integrated on silicon that can be operated mechanically and electrically. Our findings underscore the great potential of oxide membranes for utilization in advanced non-volatile electronics and highly sensitive pressure sensors.

Driven by the minimization of total energy, the multi-domain morphology is preferred in as-grown ferroelectrics to reduce the depolarization and strain energy during the paraelectric to ferroelectric phase transition. However, the complicated multi-domain is not desirable for certain high-performance ferroelectric electro-optic devices. In this work, we achieve a reproducible and stable large-area monodomain in as-grown bulk ferroelectric single crystal [Formula: see text]. The monodomain dominates the entire single crystal, which is attributed to the internal charge carriers from the photoexcited disproportionation reaction of Sn ions. The charge carriers effectively screen the depolarization field and therefore decrease the depolarization energy and facilitate the formation of monodomain. This work offers a potential approach for engineering bulk ferroelectrics with a stable monodomain, which is desirable for the high-performance ferroelectric electro-optic devices.

Freestanding perovskite oxides pave the way to novel flexural properties. Here, the authors observe the nanoscale strain gradient induced flexoelectric polarization with an unusual flexo-expansion/shrinkage effect in freestanding ferroelectric oxide.

Developing a single-phase self-rectifying memristor is desirable and functionally adaptive to dynamic environmental stimuli variations. Here, the authors report a single phase CuInP2S6 based memristor with continuously tunable current rectifying.

Piezoelectric metamaterials have received extensive attention in the fields of robotics, nondestructive testing, energy harvesting, etc. Natural piezoelectric ceramics possess only five nonzero piezoelectric coefficients due to the crystal symmetry of ∞mm, which has limited the development of related devices. To obtain nonzero piezoelectric coefficients, previous studies mainly focus on assembling piezoelectric ceramic units or multiphase metamaterials. However, only part of the nonzero piezoelectric coefficients or locally piezoelectric electromechanical modes are achieved. Additionally, it still remains a challenge for manipulating the piezoelectric coefficients in a wide range. In this work, full nonzero piezoelectric coefficients are obtained by symmetry breaking in the architected piezoelectric metamaterial. The piezoelectric coefficients are designable over a wide range from positive to negative through manipulating the directions of each strut for the three-dimensional architected lattice. The architected metamaterials exhibit multiple positive/inverse piezoelectric modes, including normal and shear deformation. Finally, a smart gradient architected piezoelectric metamaterial is designed to take advantage of this feature, which can sense the position of the normal and shear force. This work paves the way for the manipulation of piezoelectric metamaterial in a wide range with designable full nonzero piezoelectric coefficients, thereby enabling application potential in the fields of smart sensing and actuation. [ABSTRACT FROM AUTHOR]

Randomly distributed topological defects created during the spontaneous symmetry breaking are the fingerprints to trace the evolution of symmetry, range of interaction, and order parameters in condensed matter systems. However, the effective mean to manipulate topological defects into ordered form is elusive due to the topological protection. Here, we establish a strategy to effectively align the topological domain networks in hexagonal manganites through a mechanical approach. It is found that the nanoindentation strain gives rise to a threefold Magnus-type force distribution, leading to a sixfold symmetric domain pattern by driving the vortex and antivortex in opposite directions. On the basis of this rationale, sizeable mono-chirality topological stripe is readily achieved by expanding the nanoindentation to scratch, directly transferring the randomly distributed topological defects into an ordered form. This discovery provides a mechanical strategy to manipulate topological protected domains not only on ferroelectrics but also on ferromagnets/antiferromagnets and ferroelastics. [ABSTRACT FROM AUTHOR]