Flexible ferroelectrics: High-quality ferroelectric materials, which polarize in response to an electric field, are usually oxides that crack when bent. Dong et al. found that high-quality membranes of barium titanate are surprisingly flexible and super-elastic. These films accommodate large strains through dynamic evolution of nanodomains during deformation. This discovery is important for developing more robust flexible devices. Science , this issue p. 475

State-of-the-art compact antennas rely on electromagnetic wave resonance, which leads to antenna sizes that are comparable to the electromagnetic wavelength. As a result, antennas typically have a size greater than one-tenth of the wavelength, and further miniaturization of antennas has been an open challenge for decades. Here we report on acoustically actuated nanomechanical magnetoelectric (ME) antennas with a suspended ferromagnetic/piezoelectric thin-film heterostructure. These ME antennas receive and transmit electromagnetic waves through the ME effect at their acoustic resonance frequencies. The bulk acoustic waves in ME antennas stimulate magnetization oscillations of the ferromagnetic thin film, which results in the radiation of electromagnetic waves. Vice versa, these antennas sense the magnetic fields of electromagnetic waves, giving a piezoelectric voltage output. The ME antennas (with sizes as small as one-thousandth of a wavelength) demonstrates 1–2 orders of magnitude miniaturization over state-of-the-art compact antennas without performance degradation. These ME antennas have potential implications for portable wireless communication systems.

We report a continuously tunable resistive switching behavior in Pt/BiFeO₃/Nb-doped SrTiO₃ heterostructure for ferroelectric memristor application. The resistance of this memristor can be tuned up to 5 × 10⁵% by applying voltage pulses at room temperature, which exhibits excellent retention and anti-fatigue characteristics. The observed memristive behavior is attributed to the modulation effect of the ferroelectric polarization reversal on the width of depletion region and the height of potential barrier of the p-n junction formed at the BiFeO₃/Nb-doped SrTiO₃ interface.

High-valence Pr-doped $\mathrm{Bi}\mathrm{Fe}{\mathrm{O}}_3$ (BPF) multiferroic thin film was prepared by pulsed laser deposition on a $\mathrm{Pt}∕\mathrm{Ti}{\mathrm{O}}_2∕\mathrm{Si}{\mathrm{O}}_2∕\mathrm{Si}$ substrate. X-ray diffraction analysis indicates that the BPF film is of pure phase with a polycrystalline perovskite structure. The BPF film exhibited enhanced multiferroic properties: (i) a rectangular-shaped electric hysteresis loop with a large $P_r$ of $75\mu \mathrm{C}∕{\mathrm{cm}}^2$ and a low $E_c$ of $250\mathrm{kV}∕\mathrm{cm}$ at $E_{\max }$ $\sim 620\mathrm{kV}∕\mathrm{cm}$ , (ii) a saturated magnetic hysteresis loop with a large $M_s$ of $58\mathrm{emu}∕{\mathrm{cm}}^3$ , and (iii) a fatigue-free behavior after being subjected to $1.2\times {10}^9$ switching cycles, which were superior to, in some aspects, those of La- or Nd-doped $\mathrm{Bi}\mathrm{Fe}{\mathrm{O}}_3$ films reported before.