Phase transition describes a mutational behavior of matter states at a critical transition temperature or external field. Despite the phase-transition orders are well sorted by classic thermodynamic theory, ambiguous situations interposed between the first- and second-order transitions were exposed one after another. Here, we report discovery of phase-transition frustration near a tricritical composition point in ferroelectric Pb(Zr1-xTix)O3. Our multi-scale transmission electron microscopy characterization reveals a number of geometrically frustrated microstructure features such as self-assembled hierarchical domain structure, degeneracy of mesoscale domain tetragonality and decoupled polarization-strain relationship. Associated with deviation from the classic mean-field theory, dielectric critical exponent anomalies and temperature dependent birefringence data unveil that the frustrated transition order stems from intricate competition of short-range polar orders and their decoupling to long-range lattice deformation. With supports from effective Hamiltonian Monte Carlo simulations, our findings point out a potentially universal mechanism to comprehend the abnormal critical phenomena occurring in phase-transition materials.

Piezo-/ferroelectrics are essential materials for electromechanical sensors and actuators and energy harvesters in a wide range of technological applications. The demand for piezo-/ferroelectric materials with high Curie temperature (TC) arises...

Lead zirconate PbZrO3 (PZ)-based antiferroelectric (AFE) materials have received tremendous attention due to their potential applications in high density energy storage capacitors. However, PZ suffers from an ultrahigh critical electric...

BiScO3–Pb(Cd1/3Nb2/3)O3–PbTiO3 single crystals with high quality have been successfully grown by the top-seeded solution growth method and the single ferroelastic domain structures and ferroelectric behaviors have also been reviewed.

Multi-scale domain structures in the BiScO3–PbTiO3 single crystal are imagined and analyzed by birefringence imaging microscopy (BIM) and piezoresponse force microscopy (PFM), revealing the local distortion in the vicinity of the domain walls.

Preparation condition plays a critical role in the structure and properties of ceramics. However, exactly how it affects lanthanum chromate (LaCrO3)‐based conducting oxides remains poorly understood. In this work, the effects of sintering temperature on the crystal structure, microstructure, and electrical conductivity of pure and Sr2+‐/Ca2+‐substituted LaCrO3 ceramics have been investigated. It is found that the calcining temperature can be reduced by 200–300 K to obtain a single‐perovskite structure by using nano‐powders as raw materials. A sintering temperature–induced structural transition from orthorhombic Pbnm phase to rhombohedral Rtrue3¯c$R\bar 3c$ phase is found in La0.8Sr0.2CrO3, and the possible mechanism is attributed to a thermally induced transformation of the thermodynamic metastable orthorhombic to stable rhombohedral phase after thermal treatment at higher temperatures. The electrical conductivity in a broad temperature range (from room temperature up to 1923 K) is measured. The conductivity increases with the elevated sintering temperature and soaking time, and it shows a remarkable enhancement by introducing the Sr and Ca ions. These results suggest that the sintering temperature should be well controlled and optimized to obtain desired crystal structure and electrical conductivity in LaCrO3‐based materials for various applications.

In this study, a series of solid solutions of (1−x)BaTiO3-xCa(Sn1/2Zr1/2)O3 (abbreviated as (1−x)BT-xCSZ, x = 0.00–0.15) ceramics have been prepared by the conventional solid-state reaction method to search for high performance lead-free piezoelectric materials. The structural evolution, microstructure, and piezoelectric properties are investigated. X-ray diffraction (XRD) results indicate that the phase symmetry strongly depends on the CSZ content. A tetragonal phase is well-maintained in the compositions of 0 ≤ x ≤ 0.03, and coexistence of tetragonal and cubic phases is obtained in the range of x = 0.06–0.09, beyond which a pure cubic phase becomes stable. More importantly, a significantly enhanced piezoelectric coefficient of d33 = 388 ± 9 pC/N is attained in the composition of x = 0.06 in the MPB region, where a tetragonal ferroelectric phase and an ergodic relaxor phase with average cubic symmetry coexist. Based on the analysis of crystal structure and dielectric properties, a temperature-composition phase diagram consisting of four phase regions is established. This study indicates that the lead-free BT-CSZ binary system has great potential for use in electromechanical transducer applications.