相关论文: Giant optical enhancement of strain gradient in fe…
X-ray analysis of ferroelectric thin layers of Ba1/2Sr1/2TiO3 with different thickness reveals the presence of internal strain gradients across the film thickness and allows us to propose a functional form for the internal strain profile.…
We report on nanoscale strain gradients in ferroelectric HoMnO3 epitaxial thin films, resulting in a giant flexoelectric effect. Using grazing-incidence in-plane X-ray diffraction, we measured strain gradients in the films, which were 6 or…
Flexoelectricity - polarization induced by strain gradients - offers a route to polar functionality in centrosymmetric dielectrics, where traditional piezoelectric effects are absent. This study investigates the flexoelectric effect in…
Flexoelectricity describes the coupling between polarization and strain/stress gradients in insulating crystals. In this paper, using the Landau-Ginsburg-Devonshire phenomenological approach, we found that flexoelectricity could increase…
Flexoelectricity is a universal effect that generates electric polarization due to broken inversion symmetry caused by local strain gradient. The large strain gradient at nanoscale makes flexo-electric effects, especially in nanoscopic…
We report first-principle atomistic simulations on the effect of local strain gradients on the nanoscale domain morphology of free-standing PbTiO$_3$ ultrathin films. First, the ferroelectric properties of free films at the atomic level are…
Strain engineering of perovskite oxide thin films has proven to be an extremely powerful method for enhancing and inducing ferroelectric behavior. In ferroelectric thin films and superlattices, the polarization is intricately linked to…
We describe the directional growth of ferroelectric domains in a multiferroic BiFeO3 thin film, which was grown epitaxially on a vicinal (001) SrTiO3 substrate. A detailed structural analysis of the film shows that a strain gradient, which…
Modern electromechanical actuators and sensors rely on the piezoelectric effect that linearly couples strain and electric polarization. However, this effect is restricted to materials that lack inversion symmetry. In contrast, the…
The relationship between the applied elastic strain gradient and the induced electric polarization in the alpha-phase polyvinylidene fluoride (PVDF) films under bending conditions has been investigated. Our experimental studies have shown…
It has been well known that flexoelectricity can be exploited to generate an analogous piezoelectric response in non-piezoelectric materials. For the direct flexoelectric effect, the induced electric polarization is linearly proportional to…
The control of optical fields is usually achieved through the electro-optic or acousto-optic effect in single-crystal ferroelectric or polar compounds such as LiNbO3 or quartz. In recent years, tremendous progress has been made in…
The flexoelectric behaviors of solids under high strain gradient can be distinct from that under low strain gradient. Using the generalized Bloch theorem, we investigate theoretically the transversal flexoelectric effects in bent MgO…
Using Landau-Ginzburg-Devonshire theory, we considered the impact of the flexoelectro-chemical coupling on the size effects inpolar properties and phase transitions of thin ferroelectric films with a layer of elastic defects. We…
Much attention has been given recently to flexible and wearable integrated-electronic devices, with a strong emphasis on real-time sensing, computing and communication technologies. Thin ferroelectric films exhibit switchable polarization…
We reveal that strong flexoelectric effect of solids can be induced due to the signfi?cant charge migration along the strain gradient direction, which represents a new understanding of the origin of flexoelectricity. Beyond the linear…
Ferroelectric materials are characterized by the presence of an electric dipole that can be reversed by application of an external electric field, a feature that is exploited in ferroelectric memories. All ferroelectrics are piezoelectric,…
Multifunctionality as a paradigm requires materials exhibiting multiple superior properties. Integrating second-order optical nonlinearity and large bandgap with piezoelectricity could, for example, enable broadband, strain-tunable…
Epitaxial strain can be used to modify the properties of ferroelectric thin films. From the experimental viewpoint, the challenge is to fine-tune the magnitude of the strain. We illustrate how, by using a suitable combination of composition…
The polarization response of a material to a strain gradient, known as flexoelectricity, holds great promise for novel electromechanical applications. Despite considerable recent progress, however, the effect remains poorly understood. From…