Electromechanical coupling factor, k, of piezoelectric materials determines the conversion efficiency of mechanical to electrical energy or electrical to mechanical energy. Here, we provide an fundamental approach to design piezoelectric materials that provide near-ideal magnitude of k, via exploiting the electrocrystalline anisotropy through fabrication of grain-oriented or textured ceramics. Coupled phase field simulation and experimental investigation on textured Pb(Mg_1/3Nb_2/3)O₃-Pb(Zr,Ti)O₃ ceramics illustrate that k can reach same magnitude as that for a single crystal, far beyond the average value of traditional ceramics. To provide atomistic-scale understanding of our approach, we employ a theoretical model to determine the physical origin of k in perovskite ferroelectrics and find that strong covalent bonding between B-site cation and oxygen via d-p hybridization contributes most towards the magnitude of k. This demonstration of near-ideal k value in textured ceramics will have tremendous impact on design of ultra-wide bandwidth, high efficiency, high power density, and high stability piezoelectric devices.

Piezoelectric materials enable the conversion of mechanical energy into electrical energy and vice‐versa. Ultrahigh piezoelectricity has been only observed in single crystals. Realization of piezoelectric ceramics with longitudinal piezoelectric constant (d₃₃) close to 2000 pC N^–1, which combines single crystal‐like high properties and ceramic‐like cost effectiveness, large‐scale manufacturing, and machinability will be a milestone in advancement of piezoelectric ceramic materials. Here, guided by phenomenological models and phase‐field simulations that provide conditions for flattening the energy landscape of polarization, a synergistic design strategy is demonstrated that exploits compositionally driven local structural heterogeneity and microstructural grain orientation/texturing to provide record piezoelectricity in ceramics. This strategy is demonstrated on [001]_PC‐textured and Eu³⁺‐doped Pb(Mg_1/3Nb_2/3)O₃‐PbTiO₃ (PMN‐PT) ceramics that exhibit the highest piezoelectric coefficient (small‐signal d₃₃ of up to 1950 pC N^–1 and large‐signal d₃₃* of ≈2100 pm V^–1) among all the reported piezoelectric ceramics. Extensive characterization conducted using high‐resolution microscopy and diffraction techniques in conjunction with the computational models reveals the underlying mechanisms governing the piezoelectric performance. Further, the impact of losses on the electromechanical coupling is identified, which plays major role in suppressing the percentage of piezoelectricity enhancement, and the fundamental understanding of loss in this study sheds light on further enhancement of piezoelectricity. These results on cost‐effective and record performance piezoelectric ceramics will launch a new generation of piezoelectric applications.

The electrical modulation of magnetization through the magnetoelectric effect provides a great opportunity for developing a new generation of tunable electrical components. Magnetoelectric voltage tunable inductors (VTIs) are designed to maximize the electric field control of permeability. In order to meet the need for power electronics, VTIs operating at high frequency with large tunability and low loss are required. Here we demonstrate magnetoelectric VTIs that exhibit remarkable high inductance tunability of over 750% up to 10 MHz, completely covering the frequency range of state-of-the-art power electronics. This breakthrough is achieved based on a concept of magnetocrystalline anisotropy (MCA) cancellation, predicted in a solid solution of nickel ferrite and cobalt ferrite through first-principles calculations. Phase field model simulations are employed to observe the domain-level strain-mediated coupling between magnetization and polarization. The model reveals small MCA facilitates the magnetic domain rotation, resulting in larger permeability sensitivity and inductance tunability.