Mn-inlaid antiphase boundaries in perovskite structure.

Improvements in the polarization of environmentally-friendly perovskite ferroelectrics have proved to be a challenging task in order to replace the toxic Pb-based counterparts. In contrast to common methods by complex chemical composition designs, we have formed Mn-inlaid antiphase boundaries in Mn-doped (K,Na)NbO thin films using pulsed laser deposition method. Here, we observed that mono- or bi-atomic layer of Mn has been identified to inlay along the antiphase boundaries to balance the charges originated from the deficiency of alkali ions and to induce the strain in the KNN films.

The role of local non-tetragonal polar displacements in the temperature- and pressure-induced phase transitions in PbTiO-BiMeO ferroelectrics.

In situ high-pressure/high-temperature Raman-scattering analyses on PbTiO , 0.92PbTiO 0.08Bi(Zn Ti )O and 0.

Boosting Energy Storage Performance of Glass Ceramics via Modulating Defect Formation During Crystallization.

Along with the demand for further miniaturization of high and pulsed power devices, it becomes more and more important to realize ultrahigh recoverable energy storage density (W ) with high energy storage efficiency (η) and ultrahigh discharge energy storage density (W ) accompanied by high power density (P ) in dielectrics. To date, it remains, however, a big challenge to achieve high W or W in glass ceramics compared to other dielectric energy storage materials. Herein, a strategy of defect formation modulation is applied to form "amorphous-disordered-ordered" microstructure in BaTiO -based glass ceramics so as to achieve a high W of 12.

Structure, Antiferroelectricity and Energy-Storage Performance of Lead Hafnate in a Wide Temperature Range.

Lead hafnate (PbHfO) has attracted a lot of renewed interest due to its potential as antiferroelectric (AFE) material for energy storage. However, its room temperature (RT) energy-storage performance has not been well established and no reports on the energy-storage feature of its high-temperature intermediate phase (IM) are available. In this work, high-quality PbHfO ceramics were prepared via the solid-state synthesis route.

Tuning of Polar Domain Boundaries in Nonpolar Perovskite.

Domain boundaries in ferroic materials are found to have various physical properties not observed in the surrounding domains. Such differences can be enhanced and bring promising functionalities when centrosymmetric nonpolar materials encounter polar domain boundaries. In this work, a tunable polar domain boundary is discovered in an antiferroelectric single crystal.

Strain-Induced Magnetoelectric Coupling in FeO/BaTiO Nanopillar Composites.

Magnetoelectric coupling properties are limited to the substrate clamping effect in traditional ferroelectric/ferromagnetic heterostructures. Here, FeO/BaTiO nanopillar composites are successfully constructed. The well-ordered BaTiO nanopillar arrays are prepared through template-assisted pulsed laser deposition.

Effects of Composition Segregation in PMN-PT Crystals on Ultrasound Transducer Performance.

This study investigates the relationship between the composition segregation in lead magnesium niobate-lead titanate (PMN-PT; PMN-29%PT, PMN-29.5%PT, PMN-30%PT, PMN-30.5%PT, and PMN-31%PT) single crystals within morphotropic phase boundary (MPB) and the corresponding ultrasonic transducer performance through PiezoCAD modeling and real transducer testing.

Ferroelectric phase-transition frustration near a tricritical composition point.

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(ZrTi)O.

Hybrid System Combining Two-Dimensional Materials and Ferroelectrics and Its Application in Photodetection.

Photodetectors are one of the most important components for a future "Internet-of-Things" information society. Compared to the mainstream semiconductor-based photodetectors, emerging devices based on two-dimensional (2D) materials and ferroelectrics as well as their hybrid systems have been extensively studied in recent decades due to their outstanding performances and related interesting physical, electrical, and optoelectronic phenomena. In this paper, we review the photodetection based on 2D materials and ferroelectric hybrid systems.

Lead-Free KNN-Based Textured Ceramics for High-Frequency Ultrasonic Transducer Application.

Environment-friendly lead-free piezoelectric materials with excellent piezoelectric properties are needed for high-frequency ultrasonic transducer applications. Recently, lead-free 0.915(KNaLi)NbO-0.

Phase transition enhanced superior elasticity in freestanding single-crystalline multiferroic BiFeO membranes.

The integration of ferroic oxide thin films into advanced flexible electronics will bring multifunctionality beyond organic and metallic materials. However, it is challenging to achieve high flexibility in single-crystalline ferroic oxides that is considerable to organic or metallic materials. Here, we demonstrate the superior flexibility of freestanding single-crystalline BiFeO membranes, which are typical multiferroic materials with multifunctionality.

Raman Scattering Studies of the Structural Phase Transitions in Single-Crystalline CHNHPbCl.

Methylammonium lead trihalide perovskites CHNHPbX (X = Cl, Br, and I) have recently attracted huge attention as a promising candidate for highly efficient solar cell absorber materials. To understand the physical properties of halide perovskites, we investigated the CHNHPbCl single crystal by Raman scattering spectroscopy from 80 K to room temperature. Benchmarking the phonon modes and their Raman activities obtained by density functional calculations, we successfully assign the molecular vibrations of methylammonium in the frequency range from 400 to 3300 cm.

Toward a Reliable Synaptic Simulation Using Al-Doped HfO RRAM.

The potential in a synaptic simulation for neuromorphic computation has revived the research interest of resistive random access memory (RRAM). However, novel applications require reliable multilevel resistive switching (RS), which still represents a challenge. We demonstrate in this work the achievement of reliable HfO-based RRAM devices for synaptic simulation by performing the Al doping and the postdeposition annealing (PDA).

Reliable resistive switching of epitaxial single crystalline cubic Y-HfO RRAMs with Si as bottom electrodes.

Previous studies have mainly focused on the resistive switching (RS) of amorphous or polycrystalline HfO-RRAM. The RS of single crystalline HfO films has been rarely reported. Yttrium doped HfO (YDH) thin films were fabricated and successful Y incorporation into HfO was confirmed by x-ray photoemission spectroscopy.

Polymer Matrix Nanocomposites with 1D Ceramic Nanofillers for Energy Storage Capacitor Applications.

Recent developments in various technologies, such as hybrid electric vehicles and pulsed power systems, have challenged researchers to discover affordable, compact, and super-functioning electric energy storage devices. Among the existing energy storage devices, polymer nanocomposite film capacitors are a preferred choice due to their high power density, fast charge and discharge speed, high operation voltage, and long service lifetime. In the past several years, they have been extensively researched worldwide, with 0D, 1D, and 2D nanofillers being incorporated into various polymer matrixes.

Super-elastic ferroelectric single-crystal membrane with continuous electric dipole rotation.

Ferroelectrics are usually inflexible oxides that undergo brittle deformation. We synthesized freestanding single-crystalline ferroelectric barium titanate (BaTiO) membranes with a damage-free lifting-off process. Our BaTiO membranes can undergo a ~180° folding during an in situ bending test, demonstrating a super-elasticity and ultraflexibility.

Low-Voltage-Manipulating Spin Dynamics of Flexible FeO Films through Ionic Gel Gating for Wearable Devices.

Mechanical flexible electronic/spintronic devices have shown enormous application potential to impact our daily life. Here, an in situ low-voltage-controlled flexible field-effect transistor structure was exploited, which consists of a support layer (mica), functional layer (FeO), and control layer (ionic gel). By applying a low voltage (1.

Determination of chemical ordering in the complex perovskite Pb(CdNb)O.

Pure-phase Pb(CdNb)O (PCN) single crystals and ceramics with a complex perovskite structure are synthesized for the first time. The local chemical ordering in PCN has been investigated by X-ray diffraction (including diffuse scattering) and Cs-corrected transmission electron microscopy experiments. It is concluded that the PCN samples have large coherent chemical ordering regions that even extend to the long range, and the ordering model is consistent with β-type chemical ordered regions.

Ionic Modulation of the Interfacial Magnetism in a Bilayer System Comprising a Heavy Metal and a Magnetic Insulator for Voltage-Tunable Spintronic Devices.

The voltage modulation of yttrium iron garnet (YIG) is of practical and theoretical significance; due to its advantages of compactness, high-speed response, and energy efficiency, it can be used for various spintronic applications, including spin-Hall, spin-pumping, and spin-Seebeck effects. In this study, a significant ferromagnetic resonance change is achieved within the YIG/Pt bilayer heterostructures uisng ionic modulation, which is accomplished by modifying the interfacial magnetism in the deposited "capping" platinum layer. With a small voltage bias of 4.

Ferroelectric domain wall dynamics characterized with X-ray photon correlation spectroscopy.

Technologically important properties of ferroic materials are determined by their intricate response to external stimuli. This response is driven by distortions of the crystal structure and/or by domain wall motion. Experimental separation of these two mechanisms is a challenging problem which has not been solved so far.

Achieving Higher Strength and Sensitivity toward UV Light in Multifunctional Composites by Controlling the Thickness of Nanolayer on the Surface of Glass Fiber.

The interphase between fiber and matrix plays an essential role in the performance of composites. Therefore, the ability to design or modify the interphase is a key technology needed to manufacture stronger and smarter composite. Recently, depositing nanomaterials onto the surface of the fiber has become a promising approach to optimize the interphase and composites.